Many people have commented on testing different frequencies (which I hadn't thought of!). I did some quick tests today and got the same results. Fiberglass was surprisingly the best. Check out John Brandt's explanation: ruclips.net/video/3mGbPHx_8X8/видео.html
Belinda, thanks for doing this. But I think big miss here is, the frequency spectrum. It is expected Roxul Safe N Sound Rockwool bats would do much better in lower frequency spectrum which is very tough to contain compared to high frequencies. If you look at STC ratings of various insulation you might see that reflected. But I would like to see, you perform that test and provide results, which I trust more much than other's tests done with commercial interest.
@@nayudusrini that's interesting, didn't think about different frequencies would matter but it makes sense. The products funny enough only gives one number on the package.
3 года назад+6
I'm sorry, but this is only acoustic correction. So they can alter the acoustic quality of the room they're in but do nothing to "insulate". For insulation you need "mass, spring, mass" and air tightness. Those panels won't help in acoustic insulation. The only thing they do is diminish reflection and resonance.
What is amazing about rockwool, and why it is the preferred material in professional recording studio, is that it absorbs sound very evenly across the frequency range, even down to quite low frequencies.
@ALJ Studios I have freelanced and been a staff engineer in some extremely high end studios designed by top names and in all of them they utilized sophisticated geometry with several layers of rockwool lining the walls of the control room with a permeable fabric covering it. I am unaware of a better setup.
@@cf5914 cool, thank youfor sharing your experience and expertise. I feel like rocwool is such a cool concept in the same kind of way as it's just cool to think about the fact that airplanes and helicopters actually work.. they just sit on top of air from our point of view.. or the fact that the Netherlands holds the sea at bay. I think it's madness that we put rocks into essentially a badass cotton candy machine and it makes lava silly string that you can compare to wool... Have you heard of any studies into having it behind a breathable fabric? I know it was once called as dangerous as asbestos but I don't think it is. I guess if undisturbed it can't hurt too much but if not sealed very tightly I wonder if it ends up being inhaled at all. Surely singers etc would complain of their throat drying? Just wondering if you know.
@@shanemccann2915 I know of no issues with having the breathable fabric. These setups are now VERY standard in professional studios and have been for 15+ years.
The fiberglass dropped the sound pressure level more than the other materials because of the Kraft paper backing. All you were testing was airflow. The panels you hang on the wall are meant to reduce the amplitude of sound waves reflecting back to the source from the walls. You’d need to put the SPL meter on the same side of the treatment as phone to see how the insulation works to dampen reflections. What you showed is that if you want to stop outside sounds getting in any improvement in airtightness will help. Get an airtight storage container from your kitchen and put the phone in there making the noise and check the sound pressure level. It should be better than any insulation.
She states at the start that she is discussing audio absorption not reflection, most people can't make a aur vacuum box around themselves to stop exterior noise pollution
You are saying The 1mm kraft backing with zero mass made this big 40% difference ? the difference stands and the other ones dont have a kraft backing. In any case this test is not very useful because they tested a high pitch note, shouldve tested real loud bass.
Her test does a fine job at showing how much sound the materials can absorb. If you are trying to stop a sound reflecting off a surface and coming back to you with an absorption panel, the panel is going to be placed in front of the reflective surface to absorb energy from the sound waves, then it will reflect off the wall and pass back through the panel, where even more energy will be absorbed.
Yeah, in a recording studio you have to cut down on both internal reflections (to improve recording audio quality) AND external transmission (to improve isolation with the outside). It's helpful to see how useless acoustic foam is regarding isolation, but only because there's a common misconception among a lot of people that acoustic foam improves isolation, which it clearly doesn't (nor is it meant to).
This is really interesting! I think your test may be held back a little by the fact you only tested a single tone, however, as different materials tend to do a better job dampening sound at different frequencies. I'd be interested to see a follow-up!
Also if possible, make a video of sound panels with different insulation and test it in same room and how it will affect the room sound charateristics?
I tested different frequencies after making this video and got the same results. I hope to build a small room/testing facility in the future to perform more tests!
I really like your videos but on this one I would mention 2 of my issues with it: 1: I would test these materials with different frequencies, not just one high pitch sound. Probably all materials will show different characteristics through the audible frequency range. 2. The fiberglass won because it has that paper backing on one side of it and that helps a lot on high frequency. Apart of these small issues, I really hope that you will carry on and make more and more short but educational videos! Good luck with them! Dan
@@briansransom no, it's the best reflector to reflect back to the phone the test tone that is 1kHz. It is not testing the absortion capabilty for reverb of 50ms or less of a 1kHz tone in this case.
I would be curious to see how the decibel drops at different tones, especially the lowest tones in the 40hz-250hz range. From my understanding certain materials are good at the mid-high frequencies but can't absorb the pressure waves of sound as it dips into the lower range. Great video as always!
3 года назад
for lower ranges you need mass (so heavy open-celled insulation). But its only for correction. If you want to avoid annoying your neighbor those panels wont hep a bit.
Congrats on the sponsorship! Have you seen any of the channel Tech Ingredients' videos on sound isolation? I was also surprised by your results with fiberglass.
I was just trying to find that video.. There were a couple over the last couple of years and this was the one I found so far.. i think it was the one where he did the speakers and the type of insulation in them... ruclips.net/video/jjZHFIdfUFk/видео.html @Belinda Carr
@@BelindaCarr was just trying to find that video.. There were a couple over the last couple of years and this was the one I found so far.. i think it was the one where he did the speakers and the type of insulation in them... ruclips.net/video/jjZHFIdfUFk/видео.html
With respect, your test may be flawed. The video shows that the fiberglass has a backing on it which should have reflected a great deal of sound back towards the emission point. The other materials did not have that. It would be interesting to see whether the results are the same when all materials don't have a backing. My hypothesis is that it will change the results significantly. Also, using backed insulation then creates an issue for panel design. A panel using insulation with backing should place the backing on the wall side of the panel. Aside from the test methodology topic, you could expand on the topic of acoustic room treatment in the future by discussing panel designs which unevenly disperse the sound waves which are not absorbed. A big part of acoustic room treatment is reducing the magnitude of reflections coming from a specific direction and in randomizing the reflections.
Part of what sound panels are designed to do is reduce reflections of sound coming from within the room. So while it's important to be aware of how well your materials reduce noise coming from outside, part of the benefit of acoustic foam is that its shape and material are designed to reduce reverb. Perhaps there's a type of test that could be designed where you make a loud noise and then test how quickly the sound dissipates. I'd be really interested in a video like that! I work with people who create home setups for dialogue recording, and often we find that closets are a great natural space due to the absorption properties of just clothes!
I used fiberglass between bedrooms in a new house with 5/8 drywall and found it had almost no effect on ambient room noise: music, taking, moving around. I tried Safe n' Sound between two bedrooms in a second house with 5/8 drywall and found it had minimal, perhaps even less effect. Now I saw Scott MacGillivray on HGTV use Safe n' Sound and it cut the sound transmission between floors by about 95%. I'd like to watch that vid again. Of course, he used sound isolating metal channels on the rock for the ceiling. Classically, the only thing that damps sound has been MASS. Heavy stuff like concrete, masonry, concrete block and/or isolation of the silent space from the rest of the structure. This latest vid is quite interesting. I think I will use the isolating strips along with insulation of some kind on the next place.
Many of those garden variety acoustic sound panels have sand within them which can also be a good mass medium for making it more difficult for sounds or vibrations to travel through.
disappointed my 2 fav methods didn't make it into your tests. MLV is worth looking at, esp for low frequencies & keeping sound within a room. and the cheapest option (old towels), is hard to beat for lowering in-room resonance of mid/high tones.
Thanks for a great test! I wonder if the rockwool does better on lower frequencies. As far as sound blocking, the lower frequencies seem more difficult to dissipate. Possibly a frequency blocking comparison?
Yes, rockwool is better on lower frequencies. there are data sheets that show the differences between sound dampening between different insulators at different frequencies.
As others have mentioned, Rockwool should be better at absorbing in the lower frequency range. It has about twice the density of fiberglass. Interesting test results. Would like to see the lower mid tones and bass tones tested.
Your tests are measuring sound transmission, but sound panels are designed to absorb sound. The two aren't exactly the same, which is why the kraft-faced fiberglass seemingly outperformed the mineral wool batts. The angular foam isn't used to reduce sound transmission; it's used to absorb some sound and reflect the rest in different angles so as to reduce/eliminate echo/reverb. If you were to build sound panels properly, you would use Owens Corning 703/705 series rigid fiberglass boards and use fabric specifically designed to allow sound to pass through it and hit the insulation rather than reflect it. Guilford of Maine is a primary supplier of such fabric. This is not cheap, so I can understand using batts and any kind of fabric. If you were to remodel a space or build a sound room to isolate from external sounds, you'd add mass-loaded vinyl in-between layers of gypsum wallboard to the usual wall construction. This, too, is not cheap, but if you were to do it right, this is how you'd do it.
The sound meter you are using is weighted, which means high and low frequencies are tapered off, quite severely in the case of A weighting. C weighting is better but still flawed compared to Z weighting. www.noisemeters.ca/help/faq/frequency-weighting/ A proper test would use a calibrated microphone, and a frequency sweep from 20-20000Hz. A single tone test tells you virtually nothing about the acoustic properties of a material. cross-spectrum.com/measurement/calibrated_umik.html
I'm thinking that most people that want "panels" are looking to reduce reverberation (echo) in a room, to make it sound less like a gymnasium or bathroom. In a case like that you want a low density with almost anything but a flat surface. Look at those anechoic chambers. Their baffling is the audio frequency equivalent of radar absorbent 'stealth' coatings. Exposed egg crate foam would probably help the most in creating a 'dead' room. Often if using flat panels just having them off axis is going to work better than being 'normal' (perpendicular) to the sound source. *Something like a sheet of mass damping in the back of them will stop transmission all the way through and drink up a lot of whatever pressure waves _do_ make it through your primary line of defense.
It is well known that mineral wool like rockwool is one of the best sound dampening materials. (not insulation, dampening) It is open enough for air pressure to move through it and heavy enough to dampen it, converting it into heat. The thicker the mineral wool, the lower the frequency it is effective at. Rule of thumb is to use 1/4 of the lowest wavelength you want to dampen.
congrats on the sponsor you deserve it. I know this is two years old but just found it. Ive seen other videos of yours as well. Smart and pretty lady. Thank you for all you do and sharing these videos.
Yes, a good test for DB reduction, at one particular frequency at one particular point but most sound panels are primarily trying to stop annoying standing waves in a room that cause kind of, and sometimes very annoying reverb. In studios we can also make traps that are deeper in size or less deep to trap certain target frequencies. I think Mineral wool is more desirable, it is used in fire assemblies and won't burn like fiberglass does, it is water resistant, mineral wool can be expelled from the lungs and it does a slightly better job in the low end, otherwise the professional ratings are fairly close. For me I use mineral wool because it is widely available in low or really high density batts and panels and of course it is basically fireproof. The 703 fiberglass acoustic insulation is very expensive and I have to have them shipped. Here in NY I can hit my least favorite store Home Depot and get 1.5" 24x48 rockwool comfort board and double up or triple up depending on how low of frequencies I want to absorb and make pretty large panels that really work! . Comfort board is very stiff and dense doesn't even need a wood frame, although I use a frame so fastening fabric is easier. Or one can stick with batts that are smaller, less dense and need a frame. I think when testing one should compare products with the same density as well, so you are not comparing apples and oranges.
Not only was it unscientific it was inaccurate, trying to measure both absorption and transmission at once. Still it is better than some of the misinformation out there.
Congratulations on the sponsorship. Been watching your videos on storage units used as houses, glad to see you are growing more and more the potential of the channel, cheers :)
We use R30+ designed for 2x6 walls but in 2x4 wall depth. We also use 5/8 thick Sheetrock. Gets down into the low 60s and high 50s. Very effective for the $$
I use Thermafiber (I started using it in the 1970's, long before anyone heard of it) in living spaces, because I don't want to be breathing fiberglass dust. But inside a speaker cabinet, fiberglass is the only thing that works, and it you're using anything else. you're doing it wrong.
maybe i was allergic i dont know, but ive installed months ago 12 gikacoustic panels made of rockwool in my bedroom, where i m using my pc too during the day. well basically i was in the room almost everytime. i had after few days itchy and dry eyes during morning+ a lot of headache, ive tried to remove them, symtoms disappeared, put them back, symptom again each times. so in the end you can try, but begin with few panels first, and see how it goes. if you use it only during the day, i m almost sure you will never have problem, but if you are in the same room with those panels, not sure.
Doing a sound absorption comparison of insulating materials is a great idea. I'd be interested to see more. In particular, the distinction made at the start between noise and other sound such as music, speech, loud bangs and thuds, motor hum or engine drone is very significant and worth expanding on, I believe. It'd be great to see the performance of each material judged on more than one frequency and type of sound as well as different levels of loudness. I'd also like for the thickness of the material used in each experiment to be more clearly stated. I like the experimental set-up as it is simple and reproducible by anyone and also avoids sound transmission via supporting structures e.g. wooden frames and panels or plasterboard etc. which are the main culprits for sound transmission through walls, ceilings etc.
Another self-proclaimed guru comparing apples with oranges for use as bananas! First of all, the absorption materials are designed to absorb sound, not to block the sound. The fiberglass and rockwool are practically the same materials designed to be built into the walls as insulation and sound dumpening due to their absorption properties. As opposed to acoustic foam, that is designed to cover the reflective surfaces on the outside. Yet another incomparable "comparison": she compares materials of the same width and length, completely ignoring the thickness. Any acoustic engineer will tell you that sound absorption property directly depends on the thickness. The thicker the material, the lower frequency it will absorb. Yet she compares 3 or 4 inch thick rock/glasswool, that have NRC of about 1.0 to 1 inch cheap acoustic foam that has NRC of about 0.5 making absolutely no comment about it. And all she compares is 12 x 12 inches size, that has no relevance to the test she performs. The thickness and density does. Keeping the thickness of the samples the same and removing paper liner would produce comparable but very different results. I do not mind her testing the sound absorption materials for transmission loss properties as long as the experiment us done correctly. Of course anyone can compare anything to anything, but in order not to be misleading she should have said: 3 inch thick rockwool with paper liner is better/worse than 4 inch thick rockwool without the paper/ 1 inch acoustic foam. ( but worse than 3 inch brick). And then? And then she proceeds making acoustic panel just like everyone else on the internet. Which is FOR SOUND ABSORPTION purpose! So what is the point of showing transmission loss experiment to prove efficiency of "reflection loss" utility???
I’m not sure how useful this test is. Panels are typically put up to dull reflected sound, not to prevent sound from passing thru the panel. The test as shown might be informative regarding how well the different materials do at keeping high pitched sound from passing thru a wall or something. But it doesn’t really demonstrate how well the material performs at muffling reflections of sound within a room.
Thanks for the test, the result is that you have no idea about the sound yourself If you have problems with 1 khz like the sound your mobile phone makes, you should move out of your shoe box... remove the paper layer from the fiberglass and you get different results, say a realistic tone like 250 Hz and again you get a different result... You can also link more videos, you should then understand for yourself what the statement in the video is... the statement is that both rock wool and fiberglass do not stop the sound ... there are other insulating materials for such tasks, such as wood fiber ... but the most striking thing is the construction of the wall
Agree with other comments that you should perform the test with multiple frequencies, 1/2 octives min, 1/3 or less even better. Also, it wasn't a fair test due to the fiberglass' paper backing. The paper backing will block and reflect sound, not absorb it, as is desired in sound panels.
Great video Belinda. I'm interested in insulating my small home woodshop so I don't disturb the neighbors. A 4*4 meters room with just one door. I'm using power tools which produce loud high frequencies, such as a table saw. Can you give me any pointers?
Absolutely wrongly done tests. Doesn’t have to do anything with the reality. Box is not air tight, all you were testing was SPL level ls and pink sheets with paper side wins because it made the box almost air tight. Do the same but with air tight container and put the dense rockwool and you’ll see real results.
I know this is an old video but I just gotta say, I play guitar and drums, and I'm in the process of creating a recording space. I also work construction and it's always interesting to me just how much the sound in a room becomes isolated (not completely isolated, before all the know-it-alls crucify me) when you speak in it, not to mention all the noise and power tools. And of course depending on the R-value this can increase or decrease. Anyway she does a great job, and a DIY'er at that! Awesome video!
Hello Belinda, very interesting video on the sound panels. I was really surprised about the fiberglass material being the most effective. I would have thought something more dense would have been better. Congratulation on your sponsorship also. Take care. 🙂
Thank you for the very useful video. I would like to know where I can get fiberglass from. I would also like you to provide me with the purchase link. Best regards.
An acoustic treatment service offering told they'll use polyester wool, does that work for acoustic absorption? If so, to what extent compared to Rockwool or fiberglass?
Your test has nothing to do with the purpose of acoustic panel in studios. Also your fiberglass results were inaccurate because they had a reflective material to hold it in place, thus blocking the tone. Also very dangerous to your health. Acoustic panels are for treating acoustics not sound proofing.
Just for the record. If you want to do SPL tests, you need an SPL-test setup. Source (speaker playing white noise (all audible frequencies), with an output of 1Watt) @ 1m distance from the recorder (microphone). This way you get uniform results and you will be able to adjust the placing of your equipment in precise ways (speakers, microphone and your panels) Testing a random frequency will only show how that SPECIFIC frequency is affected by the dampening material. In a recording situation, you want to get rid of reverb and standing waves. You also want to decouple your microphone from any vibration (like a computer on the same desk as the microphone). Anyway. Multiple cans of worms... I can assure you that the method you used in this video does NOT work (for different reasons).
Rigid fiberglass for low/mid/high absorption (broadband) panels. Lower density Rockwell (mineral wool) for corner-chunk bass traps. Acoustic foam for wasting your money. Pink fluffy fiberglass with kraft paper for…???
Hi Belinda, I commented on the video that was linked after reading that Canadian study, NR 761. It actually says mineral wool (Rockwool) actually performed slightly better than fiber glass insulation when it came to wood stud construction. Not sure why it's the opposite here
GREAT VIDEO!!! My only critique is that we never got to see/witness/hear your final project. I was sitting on the edge of my seat, with a bunch of popcorn, waiting to see what happened....then.. * poof * Nada! Is there a part #2 coming? I was trying to see EXACTLY which fibreglass you're using. Wanna check my local homedepot here in Canada for it.
You may have fallen for the classic acoustic pannel trap! I'm new to the topic (so I might be wrong) but from the research I've done there's a difference in absorbsion and blocking. For example, concrete is very good at blocking sound but reflects it. If you were to submerge your phone in concrete, let it dry, then produce the sound, it'd be almost impossible to hear, but you wouldn't want your sound pannels made from it. The property we want in acoustic pannels is sound absorbsion since we only care about sound reflecting back to us. From what I've read fiberglass is actually worse for sound absorbsoin than both rockwool and denim but better at blocking. There's a special program to determine the sound reverberation of a room. LTT does a video using this process. Again, I'm very new to the topic so I might be wrong. LTT's video: ruclips.net/video/Sowki1N_YeY/видео.html The Acustic Pannel Trap: ruclips.net/video/HwaZhT_CrYI/видео.html
NOTE FROM PROFESSIONAL SOUND ENGENIEER: Please note that this method only test the materials sound suppressing/insulating properties and NOT the absorption coefficient nor the refractory index of it. That taken into account - Nice short video, not really any other stuff raising flags. Best Regards
Problem is for sound transmission you want mass. Rockwool has more mass and you can cram it tight to put more making it more effective. It's also more effective for low frequency.
What we care about in home audio production is absorption across as much of the audible range of frequencies as possible. You are correct that absorption decreases in the lower frequencies (bass). You tell us the dB or sound pressure level of the emitted sound from your emitter, but I didn’t catch any mention of the frequency. We need absorption data measured vs. frequency from 20 Hz to 20 kHz. You seem to be someone who could either perform this testing, or provide a learned review of available data. This would be more meaningful than stuff in a cardboard box.
I'm sorry to say your testing methodology is flawed. Sound transmission loss is one thing and sound absorption is quite another. Had you covered your cardboard box with layers of drywall sealed tightly to it, your meter would have read even lower than it did with the fiberglass (the paper facing on which probably accounts for most of the transmission loss). But as you might imagine, hanging drywall panels on your walls will not lower your RT60 (reverberation time) any more than the drywall that's already in place. This is so because while drywall's mass makes it somewhat effective at blocking sound transmission, its hard, flat surface makes it quite good at reflecting acoustical energy and therefore lousy at absorbing it. Fibrous insulation is effective at converting acoustical energy to heat (i.e. absorbing sound) but no fibrous insulation products alone are terribly effective at preventing sound transmission. For this you need inert mass (like drywall!). Insulation is stuffed inside of cavity walls because it dampens the vibrations of the air resonating between the wall panels. On its own, as your experiment showed, it doesn't block much at all.
There is a flaw in your test setup. you measured the effect of a single frequency. You also used a high-frequency sound. The further you go down with the frequency... the more noticeable the differences would be. Unfortunately, this makes the test unusable. Rockwool would prove to be more broadband and effective in the lower low frequencies. Glass wool can’t do that. But I still think it's nice that you dealt with the topic👍
While your test's were not entirely scientific they were a good approximation of what to generally expect. The results with fiberglass over Thermafiber however are a bit misleading. The Rockwool insulation is a higher quality and more stable than Thermafiber and should yield a better result. Fiberglass would also lose some of it's acoustic ability if it were to be compressed at all. I work at Canada's largest National industrial and commercial insulation distributor and can say that of all the sound studio's we have supplied in my region (Eastern Canada) Rockwool has been used exclusively and not just sound studios but gyms and wellness centers as well. Love your channel ... Cheers
Hi Belinda, As I am sure you have gathered from the other comments, you might want to return to this topic again. As you said, it is a very complex science. An important part of the science is that different materials absorb differently at different frequencies. The test tone you used is not a realistic test because the frequency is far too high. For sound panel testing, you will need to perform the tests outside or in an extremely large room (more than the quarter wave distance from each wall). You can easily cobble together a speaker (make sure you get a full range driver), and use Room EQ Wizard to perform the analysis (freeware). Driver and microphone will set you back well under $200.00 and probably under $100.00 if you go cheap.
The foam is only effective at dispersing reflected sound waves and as your test showed has little effect on pass through waves. The integral vapor barrier on the fiberglass batts would have produced the drop you saw in your 1khz sine wave test tone. Being more dense than fiberglass, the rockwool will be more effective in the low and low-mid frequency ranges. I have built a couple of mobile recording booths which typically give me a 20-25dB damping. These consist of a layer of 1/2" MDF on the exterior, a layer of 1/2" homasote board, a layer of egg-crate foam and a covering of acoustically transparent fabric to create a finish layer. Being very dense, the MDF reduces the energy transmission from outside sources. An 1/8" air gap and the homasote further dampen any sounds that do make it through the MDF. The egg-crate foam is a much cheaper alternative to the commercially available acoustic panels but is just as effective an damping the mid and high frequency reflections inside the booth. It is important to use an acoustically transparent material to close up the panels because any sound wave that cannot pass through it will be reflected, effectively acting much like a solid surface. In the above instances the only reason I didn't use rockwool was because it would have forced my wall thickness to 6 inches. As it was I was able to keep the wall panels to a 3 inch thickness.
sound loses decibel, wherein differing surfaces interact, the ultimate i have found, is to layer rockwool and carboard and poly, multiple multiple layers. we use this for dampening huge exhaust vans, but there is a company that offers a super thin poly that reduces noise as much as 18" of concrete, a layer or 2 of this can make a jet liner quiet......this material, wrapped around your sound boxes could be a massive improvement, however, last time i checked it was extremely expensive at $1000 per 30ft x 10ft x 1/2'
Hi Belinda Carr, Thanks for the useful information, I have one question may be funny but need to know. The question is can I use this Rock wool or Fibre wool for my car to reduce noise Inside Cabin the place i want to put Boot, Hood, and the door pads and floor pls suggest me
Then why most people prefer Rock wool in stead of fibreglass? I'm fairly new to this, so I don't know much about acoustic panels. Please correct me if I'm wrong. And also please suggest to me exactly what type of panels I should use for my home studio and how thick the panels should be. Thank you, I love your content. ❤️🙏
This is very, very, very old research. See cellulose acetate fibre for sound absorption. The fibre has very high surface area to mass ratio as the fibre cross section resembles a starfish. I did these tests 37 years ago and both rock wool and fibre glass were only 30% efficient relative to cellulose acetate (cigarette tow).
So is it safe to say that rockwool is better for blocking sound and fiberglass is better for adsorbing sound? I'm thinking to build a room inside a room as my vocal booth. So, if I want to put insulation between drywall to help block the sound I can use rockwool, then on the second wall I was thinking to put drywall on drywall as the external facing layer, then fiberglass insulation between the studs, then a fabric on the inside instead of drywall so that the room can be as dead as possible. I'm just basing this off seeing that the STC rating is higher for denser material and based on your experiment, the NRC rating seems to be better for less dense material. What are your thoughts?
Hi! Interesting video but I can’t help thinking that what you want to know is absorbency rather than transmission/propagation - for example: a sheet of 1inch thick marble would ace your test but reflect nearly 100% audible frequencies back into a room if used as a sound panel? Have I misunderstood?
Sound insulation is not the same as sound absorption. Please use the correct terminology. Also: your measuring method is not good. There are ISO standards describing the best methods. Each material has a sound absorption coefficient associated with them measured according to ISO standards in a reverberation chamber. You can simply look them up and compare them. No need to do your own tests. Tip: using a thicker layer (+10 cm) of absorption provides better absorption in the low frequencies.
Sound insulation or soundproofing has nothing to do with acoustic treatment. What you proved is that this whool was better for soundproofing this very frequency. The job of an acoustic pannel is so much different. I hope viewers can make the difference. Also, rockwool is generally safer to breathe than fiberglass (which is supposed to go inside the walls, not within your studio). No offence meant, but using the wrong material based on this video could be a health risk. Stay safe everyone.
Those "acoustic panels" made of foam, and come in various shapes like the sawtooth version you used are Not of any use in blocking sound. What they do do is break up reflections from the surface they sit on. Some people call that "deadening" (I don't) They basically reduce or eliminate echos.. nothing more. As far as I know they were never intended o block sound from going through them.. For that they are borderline useless.
I liked this video until the presenter showed paper-backed fiberglass insulation. How do I know the paper backing didn't have a major effect on sound absorption? The shredded denim and Rockwool have no paper backing.
I'm glad someone else brought up different frequencies as well. This is a huge factor in choosing panels for sound deadening, or dampening reflections, bass trapping etc. Your test method while interesting misses a lot of important factors. You CANNOT use a phone to test real sound properties.
This test is badly designed. Rock wool is best for sound absorption not sound insulation the treatment of rock wool should apply to reverberation reduction not sound insulation.
I noticed you left the paper backing on the fiberglass. I would think that as far as sound blocking that probably added to the decibel drop due to an added layer . Your other materials did not have a paper backing which somewhat negates your experiment. Try taking the paper off of the fiberglass. Thanks for doing this video. Jeffrey Sac
so I can use regular pink insulation as its better than green one, even if both are from rockwool ? and for putting in my ceiling, I wonder if I really should use the 6" think one or just the 3" that fits in reg. 2x4 ? I want the most quietness between me and my tenant downstairs, but does paying for the thicker one going to lower the sound enough to justify the cost, or does one layer of 3" stuff (greenstuff for example) enough sound dampening ?
thx for doing this comparison. Donnacona board also claims to be a noise reducer. It may be same as Celotex. It would be nice if you could test this out. Btw, you are my favorite RUclipsr right now.
The experiment makes a lot of sense, but we need to be careful when trying to generalize the results, especially to the scenario of wall insulation. In the case of wall insulation, there is a cavity where sound can easily go through/resonate in, and we try to fill the cavity; also, the sound source is NOT inside the wall. In this experiment however, there is no cavity to begin with, and the sound source (the phone) is sandwiched right between two fiber panels. This is a very different setup than the wall insulation case.
Slag wool is NOT comparable to Rock wool in sound absorption. We use Rock wool extensively on our building projects and tried Slag wool as it was cheaper, it was not nearly as good for sound.
Your fiberglass will settle in walls which will create air gaps. Any vector sound can find is the problem so you didn't really make a mistake. That and you didn't have the material sandwiched between anything which may impact the performance.
Complicated subject with lots of traditional beliefs. Rockwood and denim do offer better absorbtion at ≤ 250 Hz in many cases in sound panels. here transmission loss is measured, not random incidence absorbtion as needed for a sound panel. practical concerns in walls are fire and moisture resistance. For panels and gobos the practical issues are weight and plumes of fibers when touched or moved. Foam is the winner for panels if cost is no object. Denim is a good choice for DIY from retail big box. Space panels from walls for low frequency. I am a professional user with some background in small room acoustics but not an acoustic consultant, comment based on practical experience.
I really like watching your videos, but this one shows your misunderstanding of the subject. For your own credibility, I would remove this video and study up on the subject.
Your test kind of misses the point of sound panels. Sound panels aren't insulation, even though they're made of insulation. They're sound absorbers. So for example a brick wall is fantastic sound insulation but absolutely terrible sound absorption. You've really done a test that is more applicable to the placement of insulation say in a wall cavity than as an absorber hanging on a wall. The ease with which sound enters a material and the way that it's fibers efficiently convert sound energy to heat really determines the efficacy of sound panel material. Which is why fiberglass was so effective, but wedge cut foam probably would have beaten rockwool in a more applicable test of effect on reverb time of the room or effect on frequency response of the room. That's why sound panels are called sound treatment and not sound proofing. But of course insulation actually placed in walls is still sound proofing.
Google Sonopan 2, it is a relatively new sound proofing material with perhaps some of the most superior acoustical dampening properties I have ever seen. It is fairly cheap at about $30 for a 4 foot x 8 foot sheet that is 3/4 inch thick.
If you want to block sound, you are better off with a very stiff material. The products you tested are meant to reduce echo, not block sound - as such, they are very useful for reducing the reverberation time of an office or listening room. Cinderblocks, for example, are excellent at blocking sound but are useless for reducing echo.
Once toured an Armstrong Cork facility which included a walk-in anechoic chamber. Armstrong was no fan of the pink stuff but here the chamber walls and ceiling were lined with fiberglass insulation in the shape of pointy cones. This room was almost acoustically dead. The sound energy soaked into the fibers & dissipated with no return potential. Sound transmission between rooms is a different animal; good sound walls require some combo of sound energy absorption, rigidity, density or mass. Example..Stud walls lack mass and rigidity and thus tend to be poor sound isolators. A stud wall covered with lead lined wall board performs much better due to the added mass of the thin lead sheet. Concrete and masonry tend to be great at killing sound transmission, almost entirely due to mass. Room shape also plays large in dissipating sound; sound energy loves boxes with 90deg corners or perfect silos since there is little to confuse or defuse sound energy patterns. Automotive mufflers are a great study concerning damping using only sound wave confusion (pattern breaking).
I just redid my walls. I took out all the fiberglass insulation then installed three layers first layer was 1/2” foam panels second layer was 1/2“ sheet rock, third layer was 2” foam panel. Then one more 1/2” sheet rock to finish off the wall. Then you tell me to just use fiberglass insulation. Ugh.
If you're using sound panels to absorb sound echoing around in the room, be aware that this is not how they are tested. What she's measuring is sound transmission, not sound absorption. These are two completely separate functions. Ironically, you could cover the box with a layer of concrete and the levels would drop even more. But concrete absorbs almost no sound compared to any of these materials. What you want to measure is the sound reflecting (or not reflecting) off the surface. A more meaningful homebrew test would have a reflection off the absorbing material be the only path from the source to the sound level meter. It's actually kind of tricky. And yes, the answer is different at different frequencies.
Could you please do one with the RUclips video “speaker test” because they go through the entire range top to bottom of frequency just beyond the range of human hearing
What are your credentials for giving out such information. Are you a sound engineer, do you have a phd in the environmental effects of using such materials - really.
Many people have commented on testing different frequencies (which I hadn't thought of!). I did some quick tests today and got the same results. Fiberglass was surprisingly the best.
Check out John Brandt's explanation: ruclips.net/video/3mGbPHx_8X8/видео.html
Thanks so much for doing this one! 🌎☺️✌️
Belinda, thanks for doing this. But I think big miss here is, the frequency spectrum. It is expected Roxul Safe N Sound Rockwool bats would do much better in lower frequency spectrum which is very tough to contain compared to high frequencies. If you look at STC ratings of various insulation you might see that reflected. But I would like to see, you perform that test and provide results, which I trust more much than other's tests done with commercial interest.
I would think fiberglass does well because it's more bouncy and fluffy therefore absorbs the sound waves a little better.
@@nayudusrini that's interesting, didn't think about different frequencies would matter but it makes sense. The products funny enough only gives one number on the package.
I'm sorry, but this is only acoustic correction. So they can alter the acoustic quality of the room they're in but do nothing to "insulate". For insulation you need "mass, spring, mass" and air tightness. Those panels won't help in acoustic insulation. The only thing they do is diminish reflection and resonance.
What is amazing about rockwool, and why it is the preferred material in professional recording studio, is that it absorbs sound very evenly across the frequency range, even down to quite low frequencies.
The lows are the real problem they can even require sand and other heavy materials to stop, high freq are not even an issue.
I used rockwool for my atmos install in my condo The people upstair couldn't even tell I had in ceiling speakers
@ALJ Studios I have freelanced and been a staff engineer in some extremely high end studios designed by top names and in all of them they utilized sophisticated geometry with several layers of rockwool lining the walls of the control room with a permeable fabric covering it. I am unaware of a better setup.
@@cf5914 cool, thank youfor sharing your experience and expertise.
I feel like rocwool is such a cool concept in the same kind of way as it's just cool to think about the fact that airplanes and helicopters actually work.. they just sit on top of air from our point of view.. or the fact that the Netherlands holds the sea at bay. I think it's madness that we put rocks into essentially a badass cotton candy machine and it makes lava silly string that you can compare to wool...
Have you heard of any studies into having it behind a breathable fabric? I know it was once called as dangerous as asbestos but I don't think it is. I guess if undisturbed it can't hurt too much but if not sealed very tightly I wonder if it ends up being inhaled at all. Surely singers etc would complain of their throat drying?
Just wondering if you know.
@@shanemccann2915 I know of no issues with having the breathable fabric. These setups are now VERY standard in professional studios and have been for 15+ years.
The fiberglass dropped the sound pressure level more than the other materials because of the Kraft paper backing. All you were testing was airflow. The panels you hang on the wall are meant to reduce the amplitude of sound waves reflecting back to the source from the walls. You’d need to put the SPL meter on the same side of the treatment as phone to see how the insulation works to dampen reflections. What you showed is that if you want to stop outside sounds getting in any improvement in airtightness will help. Get an airtight storage container from your kitchen and put the phone in there making the noise and check the sound pressure level. It should be better than any insulation.
i agree these test are so misleading as they can be. she should remove this video asap.
She states at the start that she is discussing audio absorption not reflection, most people can't make a aur vacuum box around themselves to stop exterior noise pollution
I have to agree with you beachton123, if you watch again you will see the girl's facial expression when she explains comments on the pink fiberglass.!
You are saying The 1mm kraft backing with zero mass made this big 40% difference ? the difference stands and the other ones dont have a kraft backing. In any case this test is not very useful because they tested a high pitch note, shouldve tested real loud bass.
Her test does a fine job at showing how much sound the materials can absorb. If you are trying to stop a sound reflecting off a surface and coming back to you with an absorption panel, the panel is going to be placed in front of the reflective surface to absorb energy from the sound waves, then it will reflect off the wall and pass back through the panel, where even more energy will be absorbed.
You seem to be measure audio transmission, but I thought sound panels were to prevent audio reflection.
Yeah, in a recording studio you have to cut down on both internal reflections (to improve recording audio quality) AND external transmission (to improve isolation with the outside). It's helpful to see how useless acoustic foam is regarding isolation, but only because there's a common misconception among a lot of people that acoustic foam improves isolation, which it clearly doesn't (nor is it meant to).
Fiberglass and mineral wool do both, but insulation way better
Glad you have a good sponsor. I will keep that in mind when I need various types of insulation. Best of luck and keep going 💪
This is really interesting! I think your test may be held back a little by the fact you only tested a single tone, however, as different materials tend to do a better job dampening sound at different frequencies. I'd be interested to see a follow-up!
Ohh, yes, I am now curious about this too! We need a full spectrum sweep!
@@jesinu exactly I need t know how it does with frequencies below 200hz
Also if possible, make a video of sound panels with different insulation and test it in same room and how it will affect the room sound charateristics?
I tested different frequencies after making this video and got the same results. I hope to build a small room/testing facility in the future to perform more tests!
should use white noise
I really like your videos but on this one I would mention 2 of my issues with it:
1: I would test these materials with different frequencies, not just one high pitch sound.
Probably all materials will show different characteristics through the audible frequency range.
2. The fiberglass won because it has that paper backing on one side of it and that helps a lot on high frequency.
Apart of these small issues, I really hope that you will carry on and make more and more short but educational videos!
Good luck with them!
Dan
So the best insulator would be paper then.
@@briansransom no, it's the best reflector to reflect back to the phone the test tone that is 1kHz. It is not testing the absortion capabilty for reverb of 50ms or less of a 1kHz tone in this case.
I would be curious to see how the decibel drops at different tones, especially the lowest tones in the 40hz-250hz range. From my understanding certain materials are good at the mid-high frequencies but can't absorb the pressure waves of sound as it dips into the lower range. Great video as always!
for lower ranges you need mass (so heavy open-celled insulation). But its only for correction. If you want to avoid annoying your neighbor those panels wont hep a bit.
Congrats on the sponsorship! Have you seen any of the channel Tech Ingredients' videos on sound isolation? I was also surprised by your results with fiberglass.
Thanks, Tucker! No, I haven't, but I'm going to check out his channel now.
I was just trying to find that video.. There were a couple over the last couple of years and this was the one I found so far.. i think it was the one where he did the speakers and the type of insulation in them... ruclips.net/video/jjZHFIdfUFk/видео.html @Belinda Carr
@@BelindaCarr was just trying to find that video.. There were a couple over the last couple of years and this was the one I found so far.. i think it was the one where he did the speakers and the type of insulation in them... ruclips.net/video/jjZHFIdfUFk/видео.html
With respect, your test may be flawed. The video shows that the fiberglass has a backing on it which should have reflected a great deal of sound back towards the emission point. The other materials did not have that. It would be interesting to see whether the results are the same when all materials don't have a backing. My hypothesis is that it will change the results significantly.
Also, using backed insulation then creates an issue for panel design. A panel using insulation with backing should place the backing on the wall side of the panel.
Aside from the test methodology topic, you could expand on the topic of acoustic room treatment in the future by discussing panel designs which unevenly disperse the sound waves which are not absorbed. A big part of acoustic room treatment is reducing the magnitude of reflections coming from a specific direction and in randomizing the reflections.
Congratulations on your sponsor!
I'm glad you are beginning to get the recognition you deserve for your very informative and unbiased reporting.
Part of what sound panels are designed to do is reduce reflections of sound coming from within the room. So while it's important to be aware of how well your materials reduce noise coming from outside, part of the benefit of acoustic foam is that its shape and material are designed to reduce reverb. Perhaps there's a type of test that could be designed where you make a loud noise and then test how quickly the sound dissipates. I'd be really interested in a video like that! I work with people who create home setups for dialogue recording, and often we find that closets are a great natural space due to the absorption properties of just clothes!
I used fiberglass between bedrooms in a new house with 5/8 drywall and found it had almost no effect on ambient room noise: music, taking, moving around. I tried Safe n' Sound between two bedrooms in a second house with 5/8 drywall and found it had minimal, perhaps even less effect.
Now I saw Scott MacGillivray on HGTV use Safe n' Sound and it cut the sound transmission between floors by about 95%. I'd like to watch that vid again. Of course, he used sound isolating metal channels on the rock for the ceiling.
Classically, the only thing that damps sound has been MASS. Heavy stuff like concrete, masonry, concrete block and/or isolation of the silent space from the rest of the structure. This latest vid is quite interesting. I think I will use the isolating strips along with insulation of some kind on the next place.
Many of those garden variety acoustic sound panels have sand within them which can also be a good mass medium for making it more difficult for sounds or vibrations to travel through.
Another Belinda Carr video? HELL YEAH!!! It’s cool to see her evolution and to be here early-ish, before she eclipses 500k subscribers.
Yikes, long way to go! Thanks, Trevor :)
disappointed my 2 fav methods didn't make it into your tests. MLV is worth looking at, esp for low frequencies & keeping sound within a room. and the cheapest option (old towels), is hard to beat for lowering in-room resonance of mid/high tones.
Carpet remnants work well, also.
@@tonyhemingway7980 ...good tip, thx
Thanks for a great test! I wonder if the rockwool does better on lower frequencies. As far as sound blocking, the lower frequencies seem more difficult to dissipate. Possibly a frequency blocking comparison?
Yes, rockwool is better on lower frequencies.
there are data sheets that show the differences between sound dampening between different insulators at different frequencies.
Rockwool is all hype. In home theater rooms it has been proven time and time again that the pink stuff works better..
As others have mentioned, Rockwool should be better at absorbing in the lower frequency range. It has about twice the density of fiberglass. Interesting test results. Would like to see the lower mid tones and bass tones tested.
Your tests are measuring sound transmission, but sound panels are designed to absorb sound. The two aren't exactly the same, which is why the kraft-faced fiberglass seemingly outperformed the mineral wool batts. The angular foam isn't used to reduce sound transmission; it's used to absorb some sound and reflect the rest in different angles so as to reduce/eliminate echo/reverb.
If you were to build sound panels properly, you would use Owens Corning 703/705 series rigid fiberglass boards and use fabric specifically designed to allow sound to pass through it and hit the insulation rather than reflect it. Guilford of Maine is a primary supplier of such fabric. This is not cheap, so I can understand using batts and any kind of fabric.
If you were to remodel a space or build a sound room to isolate from external sounds, you'd add mass-loaded vinyl in-between layers of gypsum wallboard to the usual wall construction. This, too, is not cheap, but if you were to do it right, this is how you'd do it.
The sound meter you are using is weighted, which means high and low frequencies are tapered off, quite severely in the case of A weighting. C weighting is better but still flawed compared to Z weighting.
www.noisemeters.ca/help/faq/frequency-weighting/
A proper test would use a calibrated microphone, and a frequency sweep from 20-20000Hz. A single tone test tells you virtually nothing about the acoustic properties of a material.
cross-spectrum.com/measurement/calibrated_umik.html
I'm thinking that most people that want "panels" are looking to reduce reverberation (echo) in a room, to make it sound less like a gymnasium or bathroom.
In a case like that you want a low density with almost anything but a flat surface.
Look at those anechoic chambers. Their baffling is the audio frequency equivalent of radar absorbent 'stealth' coatings.
Exposed egg crate foam would probably help the most in creating a 'dead' room.
Often if using flat panels just having them off axis is going to work better than being 'normal' (perpendicular) to the sound source.
*Something like a sheet of mass damping in the back of them will stop transmission all the way through and drink up a lot of whatever pressure waves _do_ make it through your primary line of defense.
Fantastic work Belinda. It would be very interesting to share a graph of how each insulation did with various frequencies.
I made a video testing the sound dampening effect of r60 of fiberglass. It was a crazy difference.
It is the low frequencies that are so difficult to attenuate.
It is well known that mineral wool like rockwool is one of the best sound dampening materials. (not insulation, dampening)
It is open enough for air pressure to move through it and heavy enough to dampen it, converting it into heat.
The thicker the mineral wool, the lower the frequency it is effective at. Rule of thumb is to use 1/4 of the lowest wavelength you want to dampen.
Yep, especially at low frequencies. The hardest frequencies to combat in bedroom studios are the low frequencies.
Very poorly designed and poorly controlled test in my opinion
congrats on the sponsor you deserve it. I know this is two years old but just found it. Ive seen other videos of yours as well. Smart and pretty lady. Thank you for all you do and sharing these videos.
Yes, a good test for DB reduction, at one particular frequency at one particular point but most sound panels are primarily trying to stop annoying standing waves in a room that cause kind of, and sometimes very annoying reverb.
In studios we can also make traps that are deeper in size or less deep to trap certain target frequencies. I think Mineral wool is more desirable, it is used in fire assemblies and won't burn like fiberglass does, it is water resistant, mineral wool can be expelled from the lungs and it does a slightly better job in the low end, otherwise the professional ratings are fairly close. For me I use mineral wool because it is widely available in low or really high density batts and panels and of course it is basically fireproof. The 703 fiberglass acoustic insulation is very expensive and I have to have them shipped. Here in NY I can hit my least favorite store Home Depot and get 1.5" 24x48 rockwool comfort board and double up or triple up depending on how low of frequencies I want to absorb and make pretty large panels that really work! . Comfort board is very stiff and dense doesn't even need a wood frame, although I use a frame so fastening fabric is easier. Or one can stick with batts that are smaller, less dense and need a frame.
I think when testing one should compare products with the same density as well, so you are not comparing apples and oranges.
Not only was it unscientific it was inaccurate, trying to measure both absorption and transmission at once. Still it is better than some of the misinformation out there.
Congratulations on the sponsorship. Been watching your videos on storage units used as houses, glad to see you are growing more and more the potential of the channel, cheers :)
Do these dampening panels more or less have the same qualities across frequencies? I guess more specifically "lower" range frequencies.
We use R30+ designed for 2x6 walls but in 2x4 wall depth. We also use 5/8 thick Sheetrock. Gets down into the low 60s and high 50s. Very effective for the $$
I use Thermafiber (I started using it in the 1970's, long before anyone heard of it) in living spaces, because I don't want to be breathing fiberglass dust. But inside a speaker cabinet, fiberglass is the only thing that works, and it you're using anything else. you're doing it wrong.
Upstairs neighbour having a newborn during lockdown did it for me
Hi, I was wondering if any health related issues can occur. I'm planning to put a a lot of panels in my bedroom.
maybe i was allergic i dont know, but ive installed months ago 12 gikacoustic panels made of rockwool in my bedroom, where i m using my pc too during the day.
well basically i was in the room almost everytime.
i had after few days itchy and dry eyes during morning+ a lot of headache, ive tried to remove them, symtoms disappeared, put them back, symptom again each times.
so in the end you can try, but begin with few panels first, and see how it goes.
if you use it only during the day, i m almost sure you will never have problem, but if you are in the same room with those panels, not sure.
@@cmarquais oh okay, good to know. thanks!
Doing a sound absorption comparison of insulating materials is a great idea. I'd be interested to see more. In particular, the distinction made at the start between noise and other sound such as music, speech, loud bangs and thuds, motor hum or engine drone is very significant and worth expanding on, I believe. It'd be great to see the performance of each material judged on more than one frequency and type of sound as well as different levels of loudness. I'd also like for the thickness of the material used in each experiment to be more clearly stated. I like the experimental set-up as it is simple and reproducible by anyone and also avoids sound transmission via supporting structures e.g. wooden frames and panels or plasterboard etc. which are the main culprits for sound transmission through walls, ceilings etc.
Another self-proclaimed guru comparing apples with oranges for use as bananas! First of all, the absorption materials are designed to absorb sound, not to block the sound. The fiberglass and rockwool are practically the same materials designed to be built into the walls as insulation and sound dumpening due to their absorption properties. As opposed to acoustic foam, that is designed to cover the reflective surfaces on the outside. Yet another incomparable "comparison": she compares materials of the same width and length, completely ignoring the thickness. Any acoustic engineer will tell you that sound absorption property directly depends on the thickness. The thicker the material, the lower frequency it will absorb. Yet she compares 3 or 4 inch thick rock/glasswool, that have NRC of about 1.0 to 1 inch cheap acoustic foam that has NRC of about 0.5 making absolutely no comment about it.
And all she compares is 12 x 12 inches size, that has no relevance to the test she performs. The thickness and density does. Keeping the thickness of the samples the same and removing paper liner would produce comparable but very different results. I do not mind her testing the sound absorption materials for transmission loss properties as long as the experiment us done correctly. Of course anyone can compare anything to anything, but in order not to be misleading she should have said: 3 inch thick rockwool with paper liner is better/worse than 4 inch thick rockwool without the paper/ 1 inch acoustic foam. ( but worse than 3 inch brick). And then? And then she proceeds making acoustic panel just like everyone else on the internet. Which is FOR SOUND ABSORPTION purpose! So what is the point of showing transmission loss experiment to prove efficiency of "reflection loss" utility???
Despite being the clear cut winner, is there any down sides to using fiberglass as an insulation compared to rockwool's?
I’m not sure how useful this test is. Panels are typically put up to dull reflected sound, not to prevent sound from passing thru the panel. The test as shown might be informative regarding how well the different materials do at keeping high pitched sound from passing thru a wall or something. But it doesn’t really demonstrate how well the material performs at muffling reflections of sound within a room.
Thanks for the test, the result is that you have no idea about the sound yourself
If you have problems with 1 khz like the sound your mobile phone makes, you should move out of your shoe box...
remove the paper layer from the fiberglass and you get different results, say a realistic tone like 250 Hz and again you get a different result...
You can also link more videos, you should then understand for yourself what the statement in the video is...
the statement is that both rock wool and fiberglass do not stop the sound ...
there are other insulating materials for such tasks, such as wood fiber ...
but the most striking thing is the construction of the wall
Agree with other comments that you should perform the test with multiple frequencies, 1/2 octives min, 1/3 or less even better. Also, it wasn't a fair test due to the fiberglass' paper backing. The paper backing will block and reflect sound, not absorb it, as is desired in sound panels.
Great video Belinda. I'm interested in insulating my small home woodshop so I don't disturb the neighbors. A 4*4 meters room with just one door. I'm using power tools which produce loud high frequencies, such as a table saw. Can you give me any pointers?
Absolutely wrongly done tests. Doesn’t have to do anything with the reality. Box is not air tight, all you were testing was SPL level ls and pink sheets with paper side wins because it made the box almost air tight. Do the same but with air tight container and put the dense rockwool and you’ll see real results.
I know this is an old video but I just gotta say, I play guitar and drums, and I'm in the process of creating a recording space. I also work construction and it's always interesting to me just how much the sound in a room becomes isolated (not completely isolated, before all the know-it-alls crucify me) when you speak in it, not to mention all the noise and power tools. And of course depending on the R-value this can increase or decrease. Anyway she does a great job, and a DIY'er at that! Awesome video!
Hello Belinda, very interesting video on the sound panels. I was really surprised about the fiberglass material being the most effective. I would have thought something more dense would have been better. Congratulation on your sponsorship also. Take care. 🙂
Feel like natural wool insulation would have been a good one to include in these tests.
Thank you for the very useful video. I would like to know where I can get fiberglass from. I would also like you to provide me with the purchase link. Best regards.
An acoustic treatment service offering told they'll use polyester wool, does that work for acoustic absorption? If so, to what extent compared to Rockwool or fiberglass?
Are you sure that’s a crown stapler and not a Brad nailer? Great video! I’ll be switching to fiberglass for sure.
Your test has nothing to do with the purpose of acoustic panel in studios.
Also your fiberglass results were inaccurate because they had a reflective material to hold it in place, thus blocking the tone. Also very dangerous to your health.
Acoustic panels are for treating acoustics not sound proofing.
Just for the record.
If you want to do SPL tests, you need an SPL-test setup.
Source (speaker playing white noise (all audible frequencies), with an output of 1Watt) @ 1m distance from the recorder (microphone).
This way you get uniform results and you will be able to adjust the placing of your equipment in precise ways (speakers, microphone and your panels)
Testing a random frequency will only show how that SPECIFIC frequency is affected by the dampening material.
In a recording situation, you want to get rid of reverb and standing waves. You also want to decouple your microphone from any vibration (like a computer on the same desk as the microphone).
Anyway. Multiple cans of worms... I can assure you that the method you used in this video does NOT work (for different reasons).
I really like this woman and her ideas
Rigid fiberglass for low/mid/high absorption (broadband) panels.
Lower density Rockwell (mineral wool) for corner-chunk bass traps.
Acoustic foam for wasting your money.
Pink fluffy fiberglass with kraft paper for…???
Hi Belinda, I commented on the video that was linked after reading that Canadian study, NR 761. It actually says mineral wool (Rockwool) actually performed slightly better than fiber glass insulation when it came to wood stud construction. Not sure why it's the opposite here
A combination of several types is best because some are better low frequency dampeners and some are better high frequency dampeners.
GREAT VIDEO!!! My only critique is that we never got to see/witness/hear your final project. I was sitting on the edge of my seat, with a bunch of popcorn, waiting to see what happened....then.. * poof *
Nada! Is there a part #2 coming? I was trying to see EXACTLY which fibreglass you're using. Wanna check my local homedepot here in Canada for it.
You may have fallen for the classic acoustic pannel trap! I'm new to the topic (so I might be wrong) but from the research I've done there's a difference in absorbsion and blocking. For example, concrete is very good at blocking sound but reflects it. If you were to submerge your phone in concrete, let it dry, then produce the sound, it'd be almost impossible to hear, but you wouldn't want your sound pannels made from it. The property we want in acoustic pannels is sound absorbsion since we only care about sound reflecting back to us. From what I've read fiberglass is actually worse for sound absorbsoin than both rockwool and denim but better at blocking. There's a special program to determine the sound reverberation of a room. LTT does a video using this process.
Again, I'm very new to the topic so I might be wrong.
LTT's video: ruclips.net/video/Sowki1N_YeY/видео.html
The Acustic Pannel Trap: ruclips.net/video/HwaZhT_CrYI/видео.html
NOTE FROM PROFESSIONAL SOUND ENGENIEER:
Please note that this method only test the materials sound suppressing/insulating properties and NOT the absorption coefficient nor the refractory index of it.
That taken into account - Nice short video, not really any other stuff raising flags.
Best Regards
Problem is for sound transmission you want mass. Rockwool has more mass and you can cram it tight to put more making it more effective. It's also more effective for low frequency.
What we care about in home audio production is absorption across as much of the audible range of frequencies as possible. You are correct that absorption decreases in the lower frequencies (bass). You tell us the dB or sound pressure level of the emitted sound from your emitter, but I didn’t catch any mention of the frequency. We need absorption data measured vs. frequency from 20 Hz to 20 kHz. You seem to be someone who could either perform this testing, or provide a learned review of available data. This would be more meaningful than stuff in a cardboard box.
Thank you for the video. Fiberglass is so much more easier to get. I’ll be building my panels and using fiberglass for my acoustic issues.
I would use Basotect or Caruso Iso Bond. Way better to work with and for health.
I'm sorry to say your testing methodology is flawed. Sound transmission loss is one thing and sound absorption is quite another. Had you covered your cardboard box with layers of drywall sealed tightly to it, your meter would have read even lower than it did with the fiberglass (the paper facing on which probably accounts for most of the transmission loss).
But as you might imagine, hanging drywall panels on your walls will not lower your RT60 (reverberation time) any more than the drywall that's already in place. This is so because while drywall's mass makes it somewhat effective at blocking sound transmission, its hard, flat surface makes it quite good at reflecting acoustical energy and therefore lousy at absorbing it.
Fibrous insulation is effective at converting acoustical energy to heat (i.e. absorbing sound) but no fibrous insulation products alone are terribly effective at preventing sound transmission. For this you need inert mass (like drywall!). Insulation is stuffed inside of cavity walls because it dampens the vibrations of the air resonating between the wall panels. On its own, as your experiment showed, it doesn't block much at all.
There is a flaw in your test setup. you measured the effect of a single frequency. You also used a high-frequency sound. The further you go down with the frequency... the more noticeable the differences would be. Unfortunately, this makes the test unusable. Rockwool would prove to be more broadband and effective in the lower low frequencies. Glass wool can’t do that. But I still think it's nice that you dealt with the topic👍
While your test's were not entirely scientific they were a good approximation of what to generally expect. The results with fiberglass over Thermafiber however are a bit misleading. The Rockwool insulation is a higher quality and more stable than Thermafiber and should yield a better result. Fiberglass would also lose some of it's acoustic ability if it were to be compressed at all. I work at Canada's largest National industrial and commercial insulation distributor and can say that of all the sound studio's we have supplied in my region (Eastern Canada) Rockwool has been used exclusively and not just sound studios but gyms and wellness centers as well. Love your channel ... Cheers
Hi Belinda,
As I am sure you have gathered from the other comments, you might want to return to this topic again.
As you said, it is a very complex science. An important part of the science is that different materials absorb differently at different frequencies. The test tone you used is not a realistic test because the frequency is far too high.
For sound panel testing, you will need to perform the tests outside or in an extremely large room (more than the quarter wave distance from each wall). You can easily cobble together a speaker (make sure you get a full range driver), and use Room EQ Wizard to perform the analysis (freeware). Driver and microphone will set you back well under $200.00 and probably under $100.00 if you go cheap.
The foam is only effective at dispersing reflected sound waves and as your test showed has little effect on pass through waves.
The integral vapor barrier on the fiberglass batts would have produced the drop you saw in your 1khz sine wave test tone.
Being more dense than fiberglass, the rockwool will be more effective in the low and low-mid frequency ranges.
I have built a couple of mobile recording booths which typically give me a 20-25dB damping. These consist of a layer of 1/2" MDF on the exterior, a layer of 1/2" homasote board, a layer of egg-crate foam and a covering of acoustically transparent fabric to create a finish layer.
Being very dense, the MDF reduces the energy transmission from outside sources. An 1/8" air gap and the homasote further dampen any sounds that do make it through the MDF. The egg-crate foam is a much cheaper alternative to the commercially available acoustic panels but is just as effective an damping the mid and high frequency reflections inside the booth. It is important to use an acoustically transparent material to close up the panels because any sound wave that cannot pass through it will be reflected, effectively acting much like a solid surface.
In the above instances the only reason I didn't use rockwool was because it would have forced my wall thickness to 6 inches. As it was I was able to keep the wall panels to a 3 inch thickness.
sound loses decibel, wherein differing surfaces interact, the ultimate i have found, is to layer rockwool and carboard and poly, multiple multiple layers. we use this for dampening huge exhaust vans, but there is a company that offers a super thin poly that reduces noise as much as 18" of concrete, a layer or 2 of this can make a jet liner quiet......this material, wrapped around your sound boxes could be a massive improvement, however, last time i checked it was extremely expensive at $1000 per 30ft x 10ft x 1/2'
Hi Belinda Carr,
Thanks for the useful information,
I have one question may be funny but need to know.
The question is can I use this Rock wool or Fibre wool for my car to reduce noise Inside Cabin the place i want to put Boot, Hood, and the door pads and floor pls suggest me
How can they use fiberglass or rock wool with vented enclosures , just imagine all the tiny glass particles you are breathing . 😥🖐🔊😡
Hi Belinda, when making sound panels you should have measured reflection of the panel iso how much sound goes thru it.
Then why most people prefer Rock wool in stead of fibreglass? I'm fairly new to this, so I don't know much about acoustic panels. Please correct me if I'm wrong. And also please suggest to me exactly what type of panels I should use for my home studio and how thick the panels should be. Thank you, I love your content. ❤️🙏
This is very, very, very old research. See cellulose acetate fibre for sound absorption. The fibre has very high surface area to mass ratio as the fibre cross section resembles a starfish. I did these tests 37 years ago and both rock wool and fibre glass were only 30% efficient relative to cellulose acetate (cigarette tow).
So is it safe to say that rockwool is better for blocking sound and fiberglass is better for adsorbing sound? I'm thinking to build a room inside a room as my vocal booth. So, if I want to put insulation between drywall to help block the sound I can use rockwool, then on the second wall I was thinking to put drywall on drywall as the external facing layer, then fiberglass insulation between the studs, then a fabric on the inside instead of drywall so that the room can be as dead as possible. I'm just basing this off seeing that the STC rating is higher for denser material and based on your experiment, the NRC rating seems to be better for less dense material. What are your thoughts?
Hi! Interesting video but I can’t help thinking that what you want to know is absorbency rather than transmission/propagation - for example: a sheet of 1inch thick marble would ace your test but reflect nearly 100% audible frequencies back into a room if used as a sound panel? Have I misunderstood?
Sound insulation is not the same as sound absorption. Please use the correct terminology. Also: your measuring method is not good. There are ISO standards describing the best methods. Each material has a sound absorption coefficient associated with them measured according to ISO standards in a reverberation chamber. You can simply look them up and compare them. No need to do your own tests. Tip: using a thicker layer (+10 cm) of absorption provides better absorption in the low frequencies.
Sound insulation or soundproofing has nothing to do with acoustic treatment.
What you proved is that this whool was better for soundproofing this very frequency. The job of an acoustic pannel is so much different.
I hope viewers can make the difference. Also, rockwool is generally safer to breathe than fiberglass (which is supposed to go inside the walls, not within your studio).
No offence meant, but using the wrong material based on this video could be a health risk.
Stay safe everyone.
Those "acoustic panels" made of foam, and come in various shapes like the sawtooth version you used are Not of any use in blocking sound. What they do do is break up reflections from the surface they sit on. Some people call that "deadening" (I don't) They basically reduce or eliminate echos.. nothing more. As far as I know they were never intended o block sound from going through them.. For that they are borderline useless.
I liked this video until the presenter showed paper-backed fiberglass insulation. How do I know the paper backing didn't have a major effect on sound absorption? The shredded denim and Rockwool have no paper backing.
Nice video... BUT why use a phone rather than a full-range speaker??? You're only getting the higher frequencies and the SPL is tiny!
I'm glad someone else brought up different frequencies as well. This is a huge factor in choosing panels for sound deadening, or dampening reflections, bass trapping etc. Your test method while interesting misses a lot of important factors. You CANNOT use a phone to test real sound properties.
This test is badly designed. Rock wool is best for sound absorption not sound insulation the treatment of rock wool should apply to reverberation reduction not sound insulation.
Maybe the noise level drop is very related to MW density, so using a light weight MW panels around 40 kg/cubic meter may improve the insulation level.
I noticed you left the paper backing on the fiberglass. I would think that as far as sound blocking that probably added to the decibel drop due to an added layer . Your other materials did not have a paper backing which somewhat negates your experiment. Try taking the paper off of the fiberglass. Thanks for doing this video.
Jeffrey Sac
so I can use regular pink insulation as its better than green one, even if both are from rockwool ? and for putting in my ceiling, I wonder if I really should use the 6" think one or just the 3" that fits in reg. 2x4 ? I want the most quietness between me and my tenant downstairs, but does paying for the thicker one going to lower the sound enough to justify the cost, or does one layer of 3" stuff (greenstuff for example) enough sound dampening ?
thx for doing this comparison. Donnacona board also claims to be a noise reducer. It may be same as Celotex. It would be nice if you could test this out. Btw, you are my favorite RUclipsr right now.
The experiment makes a lot of sense, but we need to be careful when trying to generalize the results, especially to the scenario of wall insulation.
In the case of wall insulation, there is a cavity where sound can easily go through/resonate in, and we try to fill the cavity; also, the sound source is NOT inside the wall.
In this experiment however, there is no cavity to begin with, and the sound source (the phone) is sandwiched right between two fiber panels. This is a very different setup than the wall insulation case.
Slag wool is NOT comparable to Rock wool in sound absorption.
We use Rock wool extensively on our building projects and tried Slag wool as it was cheaper, it was not nearly as good for sound.
Your fiberglass will settle in walls which will create air gaps. Any vector sound can find is the problem so you didn't really make a mistake. That and you didn't have the material sandwiched between anything which may impact the performance.
Complicated subject with lots of traditional beliefs. Rockwood and denim do offer better absorbtion at ≤ 250 Hz in many cases in sound panels. here transmission loss is measured, not random incidence absorbtion as needed for a sound panel. practical concerns in walls are fire and moisture resistance. For panels and gobos the practical issues are weight and plumes of fibers when touched or moved. Foam is the winner for panels if cost is no object. Denim is a good choice for DIY from retail big box. Space panels from walls for low frequency. I am a professional user with some background in small room acoustics but not an acoustic consultant, comment based on practical experience.
I really like watching your videos, but this one shows your misunderstanding of the subject. For your own credibility, I would remove this video and study up on the subject.
Your test kind of misses the point of sound panels. Sound panels aren't insulation, even though they're made of insulation. They're sound absorbers. So for example a brick wall is fantastic sound insulation but absolutely terrible sound absorption. You've really done a test that is more applicable to the placement of insulation say in a wall cavity than as an absorber hanging on a wall. The ease with which sound enters a material and the way that it's fibers efficiently convert sound energy to heat really determines the efficacy of sound panel material. Which is why fiberglass was so effective, but wedge cut foam probably would have beaten rockwool in a more applicable test of effect on reverb time of the room or effect on frequency response of the room. That's why sound panels are called sound treatment and not sound proofing. But of course insulation actually placed in walls is still sound proofing.
Google Sonopan 2, it is a relatively new sound proofing material with perhaps some of the most superior acoustical dampening properties I have ever seen. It is fairly cheap at about $30 for a 4 foot x 8 foot sheet that is 3/4 inch thick.
If you want to block sound, you are better off with a very stiff material. The products you tested are meant to reduce echo, not block sound - as such, they are very useful for reducing the reverberation time of an office or listening room. Cinderblocks, for example, are excellent at blocking sound but are useless for reducing echo.
Once toured an Armstrong Cork facility which included a walk-in anechoic chamber. Armstrong was no fan of the pink stuff but here the chamber walls and ceiling were lined with fiberglass insulation in the shape of pointy cones. This room was almost acoustically dead. The sound energy soaked into the fibers & dissipated with no return potential. Sound transmission between rooms is a different animal; good sound walls require some combo of sound energy absorption, rigidity, density or mass. Example..Stud walls lack mass and rigidity and thus tend to be poor sound isolators. A stud wall covered with lead lined wall board performs much better due to the added mass of the thin lead sheet. Concrete and masonry tend to be great at killing sound transmission, almost entirely due to mass.
Room shape also plays large in dissipating sound; sound energy loves boxes with 90deg corners or perfect silos since there is little to confuse or defuse sound energy patterns. Automotive mufflers are a great study concerning damping using only sound wave confusion (pattern breaking).
I just redid my walls. I took out all the fiberglass insulation then installed three layers first layer was 1/2” foam panels second layer was 1/2“ sheet rock, third layer was 2” foam panel. Then one more 1/2” sheet rock to finish off the wall. Then you tell me to just use fiberglass insulation. Ugh.
If you're using sound panels to absorb sound echoing around in the room, be aware that this is not how they are tested. What she's measuring is sound transmission, not sound absorption. These are two completely separate functions. Ironically, you could cover the box with a layer of concrete and the levels would drop even more. But concrete absorbs almost no sound compared to any of these materials. What you want to measure is the sound reflecting (or not reflecting) off the surface. A more meaningful homebrew test would have a reflection off the absorbing material be the only path from the source to the sound level meter. It's actually kind of tricky. And yes, the answer is different at different frequencies.
Could you please do one with the RUclips video “speaker test” because they go through the entire range top to bottom of frequency just beyond the range of human hearing
What are your credentials for giving out such information. Are you a sound engineer, do you have a phd in the environmental effects of using such materials - really.
Acoustic engineering is a specialized NOT advanced branch of engineering. If it were advanced, this video would not be made.