This is probably one of the best if not the best channel about room acoustics ever. Everything you need to know explained in a very simple but effective way. No need to scroll and search in hundreds of forum posts. This is gold! Keep up. Highly appreciated.
He’s for sure been the most helpful..it’s hard to listen to most engineers speak …..just his tone sounds like his logic is undeniable and his theories absolute and u dare not challenge his word
Great videos. Most of it actually usable for home listening rooms also. I don't want to build studio but I need to treat my listening room in order to achieve balanced and natural sounding sweet spot.
@Laura Brown stop outside noise doesn't do much to your inside room acoustics itself - absorption and reflection (keep noise out) aren't the same and many stuff like Molton just *reflects* high frequencies, for bass it don't do anything at all
You have authentic depth of knowledge, and you're quite skilled at conveying complex ideas clearly. This was a real treat to watch, and the best I would ever expect to find for free. Thanks so much for sharing so generously.
One more note on open-air gapping. I read a GIK mounting test using a 4" rockwool panel where one panel was tested flat on the wall and the other was tested with a 3" open-air gap. The 3" air gap did get a small boost in absorption coefficient starting from 160 Hz and down, but started to create an absorption coefficient loss starting from 630 Hz and up. So no matter what, you don't get something for nothing. It's a tradeoff. Again in this situation though, it's still better to just use a 6" panel over a 4" panel open-air gapped.
Soon after I wonder about an aspect of room treatment I get recommended a video where you cover the topic. It's invaluable what you're doing for us newbies of home studio setups. Thanks a million
I’m curious, o guess we’re assuming the gap is against Sheetrock?Would the measurements change if the wall was treated? For example: if I had a room that was treated with 2 inch, then added 6 inch with 6 inch gap in various spots as needed better somehow? Rather than just having a gap with sheet rock.
Just discovered your channel….. This simple formula you described is priceless!. I was always told it can be a good idea to leave a small gap behind hung panels, but I never knew there was a specific formula behind getting the best results. Great stuff !! 😉👍
I have reasons for needing the air gap other than performance - at least two of my planned absorber positions have light switches which I need access to. Using thicker panels is pretty much out of the question. What I don't see a lot of advice about is how to actually mount panels (in my case GIK) with an air gap. I know GIK have brackets for ceiling clouds, but I don't know if they're the best or easiest option for wall mounting. Any tips would be appreciated!
How would that work if the panel is put in a corner? (Meaning the air gap would be triangular). Does the same rules apply in terms of ratio? Keep up the good content!
Super informative video, thanks for that. Does this mean that I can have air gaps for my corner bass traps instead of super chunks, and the absorption may be the same or even better?
Excellent video. Clear and concise backed by scientific principles. You obviously know exactly what you're talking about. I'm an immediate disciple. Many thanks.
Some acoustic panels come with a solid backing material such as plywood. In this case I assume that an air gap does nothing, since the wood back acts like a wall. Correct?
most of the low frequencies don't really care about that, they go through - that is why you see bass traps reducing the amplitude of bass frequencies while having a hard outer shell (and sometimes hard inner spacers with air gap). Hope this makes sense. I think for mid frequencies it might be rather true though. Also, real life often overwrites these nice charts, these are just guidelines.
Very interesting, so if I understand the conclusion at the end correctly, it would be beneficial to have an air gap (all be it not more than the core size), but if you have the space and resources it would still be better to just have a thicker absorption panel that would take up the same space (panel + gap). I did elevate some of my wall panels with acoustic foam on the sides of some tiles (so it has a gap to the wall inside but doesn't have open spaces on the side). But next treatment I will just get foam sheets to just have a thicker panel to elevate them. Thanks a lot! Great channel!
I have a 10cm thick ceiling absorber preventing me from early reflection at listening spot. Does this mean I have to hang this not more than 10cm from the ceiling to avoid the non-effectiveness in the lower mids? Thank you for all this incredible wisdom you share here with us.
The absorber should be place as close as possible to the 1/4 wavelength position, where the amplitude is greatest and the absorption most effective. Longer wavelengths have 1/4 wavelengths farther from the wall, so the absorber must be moved farther from the wall to be effective, compared with shorter wavelengths. Please correct me if I am wrong.
@@Harald_Reindl😂rite or theres a few tools they make to help combat that 1 is a device called a SWIFFER DUSTER &. 2 thee most common tool for this is called a BROOM, sh!t use a dirty tee shirt. CLEAN YOUR STU!!!😂😂
Great explanation! I have a related question... what would be the difference in having an absorption panel close/against the wall as opposed to having them hanging on a stand closer to the listening position, and say 3 feet away from left and right wall?
it seems the graph with the air gap has more comb filtering going on, though. as much as you may save a few dollars by using an air gap, wouldn't it be better to have a flatter dampening/absorption curve, unless the peaks and valleys are precisely opposite what you're attempting to "fix"?
Great video, thank you. To counteract the dip in mid-range frequency absorption with a large gap, would it be prudent to put an additional layer of absorption on the wall (so effectively double layering the panels, one against the wall, one a few inches off)?
Depends on the room really. Maybe you don’t want less mid and if so then just make the absorption thick and thin but no inbetween or add bass traps and those ugly useless foam because that pretty much only touches high frequencies
Hi, i plan to rent a 100 sqm room as a dance studio ( 3.5 meter height ) , i will be using the cement ceiling for ceiling mounts for my hoops/poles . Anyway, the tenant beside me will be a 24 hr CALL CENTER , we still don’t have a partition between us ( on the partition i plan to install the dance mirror ) . For the partition, the owner will install a DOUBLE wall hardiflex . Will that be enough to deaden or block the sound for both rooms? A supplier suggested to : Insert 3 or 4 INCHES ROCKWOOL fiber in between the hardiflex, then on my side - place the MASS LOADED VINYL ROLL on top of the hardiflex acoustic, ( there might be a gap in between this and the actual wall where i will place the mirror , they suggested that instead of using plywood for the mirror to be place, i should use SILICATE BOARD as a replacement, then finally the mirror. Not sure if there is a more cost effective way for this . Thanks your reply will be much appreciated
Just a question: how to know how much of absorbtion you need in a specific room? how to know how much you want to kill in the spectrum, and not only where?
What about putting the panel with a gap from the wall, but filling the gap with foam, in order to capture those mid frequencies? In other words, wall, foam, panel...?
This may be obvious to some, but misleading for others. When you state the depth of the absorption material in your calculations I assume this means the material itself, not the depth of the frame of the panel. For an example some of my panels are 3.25 inches deep, but the absorption material is at the front away from the wall and is only 2 inches deep. That should mean that material is already 1.25 inches away from the wall and close to the optimal equi-distance from the wall as the depth of the absorption. Were panels manufactured with the panel frames twice the depth of the absorbent material there would be no need to hang panels for optimal absorption. Please correct me if I have misunderstood.
I am thinking in using now, silk screening mesh fabric to cover my panels. It's made of nylon, stretches very well, and allows the sound to go inside the rockwool 100% letting it do its job completely well, the way rockwool is supposed to work. It is not expensive if bought by the roll at Walmart. Using the correct opening, won't allow the tiny pieces of rockwool get out of the panel, that are really bad if you breath them. What do you think? .
Do the cuts and shapes of acoustic foams actually make any difference at all? For eg: compared to a thick block of 2 inch acoustic foam , is a 2 inch pyramid foam better or worse? Or is it a marketing strategy to make less amount of foam more appealing by saying : more cuts means more surface area means more absorption etc?
Amazing, really - thank for the session on what to be thinking about before you start hanging your absorption panels..(I was just in the process of doing this) ...and thank you for the valuable set up procedure on how to hear the sweet spot for your speaker placement, I was able to understand the process and it gave me more of an insight on what I should have been focusing on - Thank you Acoustic Insider!
When you switch that calculator to "random incidence", that effect totally disappears and then it's just deeper = better. Now I'm wondering if I should back-fill my absorbers for more even absorption. EDIT: For treating modal frequencies, 0 degrees incidence works since those standing waves hit the wall dead on in a rectangular room. So it's better to use the material to cover more area if making it thicker doesn't increase bass absorption.
Great video as always. Question: Is there an upper limit on rockwool thickness when it comes to bass trapping? For example, let's say you have a room big enough where you can pack a full 1m (!) of rockwool against the walls. Is the bass even going to get through that much material or are you just wasting rockwool at that poing? Thanks as always for the great videos.
I'd simulate it in the absorption sim Jesco showed here. It's vital to enter the Rockwool characteristics in the variables. Or, you can split it like he suggested, ie. .5m material with .5m gap. Or just go for it ... put up a full 1m depth. Typically the thicker the velocity trap, the less dense the material requirements are.
@@FOH3663 Good tip! I should have mentioned that I did this and that's what the simulator reported (after about .5m there is very little difference). The only part I couldn't figure out was the flow resistivity for Rockwool RWA-45. From what I have seen, it's right around 10k (the default value at AcousticModeling.com) but that was extrapolated data from a random acoustics forum, not an official Rockwool spec sheet. I'm not sure they've posted that information for RWA-45. Anyway thanks for your good response!
@@LeoMakes You probably got it sorted by now, but it mainly depends on how low your speakers extend and how dense the material you're using is. So it could be worth it if: a) The insulation you're using has very low flow resistivity (1000-5000) b) Your speakers are producing sound in the 20-40hz range If the flow resistivity is high, you won't get much beyond 300-500mm thickness. If your speakers taper off at 50hz, there's no point anyway because the main absorption increase is to frequencies below that.
How does this work with corners? the air gap will obviously be rectangular in shape... I'm sure it's fine since that is the way most people cover their corners but I'm still curious
Did I get this right?… The green line representing the sound reduction of a gap less 100mm panel has a far more linear response with slightly wider frequency absorption range in the low end? If so, I feel the cost of the extra 50mm insulation is worth it. I’ve chosen to go with a 100mm framed panel with 60mm depth of a more semi- rigid mineral wool board with 40mm of a less rigid lower density mineral wool board facing it.
Great video, thank you! To-the-point, and explained the 1-to-1 ratio of thickness to air gap very clearly. I am currently about to build acoustic panels with 3.5” thick mineral wool insulation, so I’ll be planning on building stands for those panels so that they sit 3.5” away from the wall. I know it’s not 6 inches thick (which would be most ideal), but I also don’t have a lot of room for 6 inch thick panels in my home theater testing room that I’m building for my own channel. Not the most ideal, but better than no panels at all. 😁🤘 Thanks again! You have a new subscriber!
Hi! Would I be able to use some clips from this video in my own video about building out my own DIY acoustic panels? No audio - just me talking over some short clips from this video, since I want people to know where I got the science behind it. I reference this video a few times, so hopefully it’ll get more views too! Thanks! 😁
Having an air gap at all is a debatable topic. The issue of panel air gaps center around having an "open" air gap vs. a "sealed" air gap between the panel. Some have said that an open air gap may not do much acoustically. Looks like more numerical data is needed in the open vs. sealed debate. The documentation for the Porous Absorber Calculator does not make it clear whether the air gap measurement is based on open or sealed.
Using the Porous Absorber Calculator at the acousticmodelling link in the video, the half-wave dip in absorption you point out is much less of a problem when the calculator's Random Incidence option is checked. Does this imply that using pyramidal or triangular-ridged acoustic absorption foam is a better choice than flat-surfaced foam for deep air gaps?
I just came across this video, what an excellent explanation thank you! I have 1 follow up question, so for example assuming a 2" sound absorbing panel and a 2" air gap, would a 2" thick Rockwool inside of a 4" deep frame, mounted flush to the wall, still be the same as a 2" deep panel, mounted 2" off of the wall?
How would you implement the air gap ? I've got several 6'' porous absorbers and would love to raise my absorption coefficient from 0.4 to 0.6 at 100 Hz as thats exactly the problem-frequency-band of my room. I just don't know what's the best way to implement the gap. Would be great if you could do a hands on video how you'd install a gap like that. cheers from austria :)
I cut four 1.5" cubes of rigid foam (the white shiny stuff that's often used to package electronics) and hot glued them to the back of my (DIY, 7" thick) rockwool panels, then re-hung them using picture frame wire. The blocks are glued a few inches in from the corners, so they aren't visible. Now the panels sit securely on their four 'feet', and appear to be floating away from the walls... a nice look that would be even more awesome with some wall-washing LEDs added to the panel backs. The panels are nothing but double-thick rockwool sheets sewn in a fabric casing with either a minimal wooden frame on the back (new ones) or a solid sheet of thin MDF (early ones), so they're rigid enough and weight isn't an issue. I also made a 3.5" thick ceiling cloud using a back frame (with a bit more structure to it, and some buttons to hold things together) and hung it a few inches below the ceiling. I did this more to facilitate installation than for any audio benefit, so it's nice to hear that's added. I see that the software includes the phrase "rigid backing"... I'm assuming this means a solid back like a sheet of thin plywood or MDF board, versus a sparse frame and fabric. Does this backing make a huge difference in performance?
Really interesting video, thanks for the calculator! Would be keen to understand if it is possible to do similar measurements with a flat panel in a corner where the depth is then not just a fixed amount, instead deeper in the middle than the edges.
Hi Jesco, I've seen this on an acoustic website and it's completely thrown me re the gap behind a panel. Can you throw any light on this? NWAA Labs, Inc 2017 ASA NOLA Absorption Myth: Wall mounted panels that are spaced off of the walls will increase their low frequency absorption as the space behind increases. Fact: This is only partially true. The low frequency absorption only increases when the spacing from the wall does not exceed 1 inch. The effect disappears after 1 inch. This only applies to unimpeded airspace.
Good video and the PDF was an interesting read. My studio is visually a mess but sonically I'm delighted. Gradually I am tidying the room but the question is, how much harm will tidying the room do to the acoustics? I'm seriously considering putting up drapes to simply hide the cluttered shelves! 😀
Curtains will over the shelves will absorb too much high frequencies. Would be better off just moving all the shelves to another room or a storage cupboard.
Thanks for your awesome content! Very well explained and easy to digest even not having a lot of upfront knowledge. Is this (in a more moderate way) also applicable to living rooms where you listens to music and want to treat the room? I‘m thinking about the wall behind the speakers and basically building a big wooden frame with Pamela’s you find in centralized concert rooms and put absorption material behind sand possibly an airspace. In the living room I‘d not make this deepen than 10cm though as it would otherwise interfere to much with the room and it‘s usage as a living room
Is this result due to the fact that you are moving the panel closer to the speaker?
3 года назад+1
Great channel, subbed and checking all your other videos :) I have a question though, going to build new panels soon, (200mm depth cotton wool) but i'm never quite sure which density would suit my needs. Any info on that ?
Ok, so now after watching the GIK Acoustics video on Air Gaps, it's pretty clear now that air gapping is really not a good idea unless you are doing extensive frequency testing and you know exactly what you are doing. If you are trying to float a 2" panel an inch or two off of the wall, then it's better to just use a 4" panel flat on the wall. And if you feel like you need to float a 4" panel off of the wall, then it's better to move up to a 6" panel flat on the wall. It appears that... yes, a "sealed" air gap is better than a open air gap, and an open air gap can make your situation worse if you aren't doing serious frequency measuring. Performance-wise it's better to just use a thicker panel flat on the wall over a thinner panel with an open air gap. It also looks like most GIK panels come with an air gap in the back portion of the frame, but it's also sealed with an acoustic cloth cover. Also in smaller rooms, it's almost automatic that you should be using 4" thick panels instead of 2" panels.
Thank you! Great presentation. Question: we are getting repetitive bass sounds...day and night constantly from neighbors...! We have dual pane windows and dampers. Could bass be traveling via our plumbing? We love music...but what can we do on the entire length of one side of the house??? We live on a corner and basically have six neighbors. Echo effect probably plays a role? Any suggestions welcomed. Jim
So does this same principle apply to the actual furniture in the room too example small side board pulled 1 inch from the wall instead of being pushed right up against the wall ?
Using a 6" Velocity traps placed 6" off the wall will begin to effectively trap bass. What does it do to the mids and highs? How much of the mids and highs do we want to remain active in the room? To place a 6" panel 6" off the wall, do you want air flow behind the panel (see right through from side to side along the wall) or can you increase the depth of the frame to the sides and top and bottom rest flat against the wall while the air gap exists between the wall and the inner core? Many Thanks! Great video!
Just out of Curiosity, is there any benefit observed if the panel is mounted like a wedge, for example, closest to the speaker has some or no air gap, with furthest away having the opposite property?
hi , thanks alot for your help , i checked the site and i have a question , what if we use 2 layers of 4 inch panels each one with 4 inch air gap ? does it work ?
Could you please explain why do you suggest caring about base traps while for the same money you can cover 2x (or 3x) of wall space with thinner foam for the same money? The low band of human ear directionality (phase-sensitive) is centered around 500Hz, and covering down to 300Hz (with an air gap, on -3dB) may appear to be more beneficial than going into huge room-eating expense with base traps (which you can eq electronically for a rather wide sweet spot).
Love the channel, been binge watching, about to build a studio in my guest house. Hypothetical question, just out of curiosity: How would a multiple panel/gap "sandwich" combination compare to single panel/gap of equal total thickness? Lets say we cut a panel in half by thickness, and use it with half the gap between the wall and first panel, then another equal gap between panel one and two. Would that affect absorbtion in any meaningful way? Taking it further, would a increasing/decreasing or shuffled thickness/gap multilayer sandwich make any perceptible difference? Lets say | is one unit thickness, and space is a unit gap, something like: room||| || | wall
We have 25 ft ceilings and an echo problem and would like to make decorative acoustical panels on one wall. If they are 2 in deep how large should the air gap be for normal conversation
Using the calculator, what would be the ideal look of that graph? Not sure that makes sense. I have 8 2ft x 4ft panels each one is 6 1/4" think with about 2 inch gap behind. Five are on the wall and 3 are on the ceiling. I like the sound but haven't measured it to find out what it sounds like.
Great video. One question I have never seen. If you use a 3” foam and make it real long. Hey let’s say rapping all your ceiling perimeters. Will it equal to just less 6” deep foam. Or is it the depth of the material that matters. Cube inches in a different way. 🤷🏽♂️
I don’t think so. You’re talking about reducing the energy of the sound wave. So it’s linear in the path of the wave. The video talks about putting that 3” foam 3” off the wall, which could get you similar results. But if you had a room and covered one wall with 6” of foam and the opposing wall with no treatment, i think it would be different than 3” of foam on both walls.
bro i have a question, i just installed Rockwall AP , i want to know is it safe to breath around them on the studio as i cant breath very well on the room. did you hear about any breathing problem could happen or cancer casing effect on keep rock wall panel around you. thank you
This is probably one of the best if not the best channel about room acoustics ever. Everything you need to know explained in a very simple but effective way. No need to scroll and search in hundreds of forum posts. This is gold! Keep up. Highly appreciated.
I was going to write this as a comment, but now i dont need to ^^ Im so happy and thankful Jesco Lohan.
He’s for sure been the most helpful..it’s hard to listen to most engineers speak …..just his tone sounds like his logic is undeniable and his theories absolute and u dare not challenge his word
Great videos. Most of it actually usable for home listening rooms also. I don't want to build studio but I need to treat my listening room in order to achieve balanced and natural sounding sweet spot.
@Laura Brown stop outside noise doesn't do much to your inside room acoustics itself - absorption and reflection (keep noise out) aren't the same and many stuff like Molton just *reflects* high frequencies, for bass it don't do anything at all
You have authentic depth of knowledge, and you're quite skilled at conveying complex ideas clearly. This was a real treat to watch, and the best I would ever expect to find for free. Thanks so much for sharing so generously.
One more note on open-air gapping. I read a GIK mounting test using a 4" rockwool panel where one panel was tested flat on the wall and the other was tested with a 3" open-air gap. The 3" air gap did get a small boost in absorption coefficient starting from 160 Hz and down, but started to create an absorption coefficient loss starting from 630 Hz and up. So no matter what, you don't get something for nothing. It's a tradeoff. Again in this situation though, it's still better to just use a 6" panel over a 4" panel open-air gapped.
Fantastic. Answered a question I've had for years, which I've used my intuition to fix. Excellent.
Soon after I wonder about an aspect of room treatment I get recommended a video where you cover the topic. It's invaluable what you're doing for us newbies of home studio setups. Thanks a million
I’m curious, o guess we’re assuming the gap is against Sheetrock?Would the measurements change if the wall was treated? For example: if I had a room that was treated with 2 inch, then added 6 inch with 6 inch gap in various spots as needed better somehow? Rather than just having a gap with sheet rock.
Just discovered your channel….. This simple formula you described is priceless!. I was always told it can be a good idea to leave a small gap behind hung panels, but I never knew there was a specific formula behind getting the best results.
Great stuff !! 😉👍
I have reasons for needing the air gap other than performance - at least two of my planned absorber positions have light switches which I need access to. Using thicker panels is pretty much out of the question.
What I don't see a lot of advice about is how to actually mount panels (in my case GIK) with an air gap. I know GIK have brackets for ceiling clouds, but I don't know if they're the best or easiest option for wall mounting.
Any tips would be appreciated!
How would that work if the panel is put in a corner? (Meaning the air gap would be triangular). Does the same rules apply in terms of ratio?
Keep up the good content!
Hi, do you sell the plots how to make the absorbers/basstraps, basstraps/diffusers you use? thanks
Super informative video, thanks for that. Does this mean that I can have air gaps for my corner bass traps instead of super chunks, and the absorption may be the same or even better?
Excellent video. Clear and concise backed by scientific principles. You obviously know exactly what you're talking about. I'm an immediate disciple.
Many thanks.
Some acoustic panels come with a solid backing material such as plywood. In this case I assume that an air gap does nothing, since the wood back acts like a wall. Correct?
most of the low frequencies don't really care about that, they go through - that is why you see bass traps reducing the amplitude of bass frequencies while having a hard outer shell (and sometimes hard inner spacers with air gap). Hope this makes sense. I think for mid frequencies it might be rather true though. Also, real life often overwrites these nice charts, these are just guidelines.
Very interesting, so if I understand the conclusion at the end correctly, it would be beneficial to have an air gap (all be it not more than the core size), but if you have the space and resources it would still be better to just have a thicker absorption panel that would take up the same space (panel + gap). I did elevate some of my wall panels with acoustic foam on the sides of some tiles (so it has a gap to the wall inside but doesn't have open spaces on the side). But next treatment I will just get foam sheets to just have a thicker panel to elevate them. Thanks a lot! Great channel!
What can I say but, Excellent information and presentation.
I have a 10cm thick ceiling absorber preventing me from early reflection at listening spot. Does this mean I have to hang this not more than 10cm from the ceiling to avoid the non-effectiveness in the lower mids? Thank you for all this incredible wisdom you share here with us.
The absorber should be place as close as possible to the 1/4 wavelength position, where the amplitude is greatest and the absorption most effective. Longer wavelengths have 1/4 wavelengths farther from the wall, so the absorber must be moved farther from the wall to be effective, compared with shorter wavelengths. Please correct me if I am wrong.
Very very useful info, and that site is a great tool. Question though, what density is ideal?
one of the best videos in the topic I've ever seen ... now to actually execute the ideas in my "bedroom" studio :)
100% of spiders approve of air gaps between the panel and the wall.
turn up the music to blow them out
> 100% of spiders
I hate you.
😂
😆
@@Harald_Reindl😂rite or theres a few tools they make to help combat that 1 is a device called a SWIFFER DUSTER &. 2 thee most common tool for this is called a BROOM, sh!t use a dirty tee shirt. CLEAN YOUR STU!!!😂😂
Great explanation! I have a related question... what would be the difference in having an absorption panel close/against the wall as opposed to having them hanging on a stand closer to the listening position, and say 3 feet away from left and right wall?
it seems the graph with the air gap has more comb filtering going on, though. as much as you may save a few dollars by using an air gap, wouldn't it be better to have a flatter dampening/absorption curve, unless the peaks and valleys are precisely opposite what you're attempting to "fix"?
Great video, thank you. To counteract the dip in mid-range frequency absorption with a large gap, would it be prudent to put an additional layer of absorption on the wall (so effectively double layering the panels, one against the wall, one a few inches off)?
Depends on the room really. Maybe you don’t want less mid and if so then just make the absorption thick and thin but no inbetween or add bass traps and those ugly useless foam because that pretty much only touches high frequencies
Do you have an rt60 freq response of the room?
Hi, i plan to rent a 100 sqm room as a dance studio ( 3.5 meter height ) , i will be using the cement ceiling for ceiling mounts for my hoops/poles . Anyway, the tenant beside me will be a 24 hr CALL CENTER , we still don’t have a partition between us ( on the partition i plan to install the dance mirror ) . For the partition, the owner will install a DOUBLE wall hardiflex . Will that be enough to deaden or block the sound for both rooms? A supplier suggested to : Insert 3 or 4 INCHES ROCKWOOL fiber in between the hardiflex, then on my side - place the MASS LOADED VINYL ROLL on top of the hardiflex acoustic, ( there might be a gap in between this and the actual wall where i will place the mirror , they suggested that instead of using plywood for the mirror to be place, i should use SILICATE BOARD as a replacement, then finally the mirror. Not sure if there is a more cost effective way for this . Thanks your reply will be much appreciated
Very well explained and clear with the right balance of theory and practical application - I will be checking out your channel - Thank you !
Just a question: how to know how much of absorbtion you need in a specific room? how to know how much you want to kill in the spectrum, and not only where?
Jesco, thank you so much, you've opened my eyes on acoustic
What about putting the panel with a gap from the wall, but filling the gap with foam, in order to capture those mid frequencies? In other words, wall, foam, panel...?
the gap is to save money and material for a *similar* result, fill it
This may be obvious to some, but misleading for others. When you state the depth of the absorption material in your calculations I assume this means the material itself, not the depth of the frame of the panel. For an example some of my panels are 3.25 inches deep, but the absorption material is at the front away from the wall and is only 2 inches deep. That should mean that material is already 1.25 inches away from the wall and close to the optimal equi-distance from the wall as the depth of the absorption. Were panels manufactured with the panel frames twice the depth of the absorbent material there would be no need to hang panels for optimal absorption.
Please correct me if I have misunderstood.
Yes, the material itself.
I am thinking in using now, silk screening mesh fabric to cover my panels. It's made of nylon, stretches very well, and allows the sound to go inside the rockwool 100% letting it do its job completely well, the way rockwool is supposed to work. It is not expensive if bought by the roll at Walmart. Using the correct opening, won't allow the tiny pieces of rockwool get out of the panel, that are really bad if you breath them. What do you think?
.
Do the cuts and shapes of acoustic foams actually make any difference at all? For eg: compared to a thick block of 2 inch acoustic foam , is a 2 inch pyramid foam better or worse?
Or is it a marketing strategy to make less amount of foam more appealing by saying : more cuts means more surface area means more absorption etc?
keep it coming, best treatment advice on the tube !
Amazing, really - thank for the session on what to be thinking about before you start hanging your absorption panels..(I was just in the process of doing this) ...and thank you for the valuable set up procedure on how to hear the sweet spot for your speaker placement, I was able to understand the process and it gave me more of an insight on what I should have been focusing on - Thank you Acoustic Insider!
Very good and logical walk through of acoustics wave speed vs spl.
When you switch that calculator to "random incidence", that effect totally disappears and then it's just deeper = better.
Now I'm wondering if I should back-fill my absorbers for more even absorption.
EDIT: For treating modal frequencies, 0 degrees incidence works since those standing waves hit the wall dead on in a rectangular room. So it's better to use the material to cover more area if making it thicker doesn't increase bass absorption.
This is great, good job Jesco!
Great video as always. Question: Is there an upper limit on rockwool thickness when it comes to bass trapping? For example, let's say you have a room big enough where you can pack a full 1m (!) of rockwool against the walls. Is the bass even going to get through that much material or are you just wasting rockwool at that poing?
Thanks as always for the great videos.
great question, man.
I'd simulate it in the absorption sim Jesco showed here. It's vital to enter the Rockwool characteristics in the variables.
Or, you can split it like he suggested, ie. .5m material with .5m gap.
Or just go for it ... put up a full 1m depth.
Typically the thicker the velocity trap, the less dense the material requirements are.
@@FOH3663 Good tip! I should have mentioned that I did this and that's what the simulator reported (after about .5m there is very little difference). The only part I couldn't figure out was the flow resistivity for Rockwool RWA-45. From what I have seen, it's right around 10k (the default value at AcousticModeling.com) but that was extrapolated data from a random acoustics forum, not an official Rockwool spec sheet. I'm not sure they've posted that information for RWA-45. Anyway thanks for your good response!
@@LeoMakes
You're welcome
Gearslutz acoustics forum would be a solid source for greater specificity in the material density etc.
@@LeoMakes You probably got it sorted by now, but it mainly depends on how low your speakers extend and how dense the material you're using is. So it could be worth it if:
a) The insulation you're using has very low flow resistivity (1000-5000)
b) Your speakers are producing sound in the 20-40hz range
If the flow resistivity is high, you won't get much beyond 300-500mm thickness. If your speakers taper off at 50hz, there's no point anyway because the main absorption increase is to frequencies below that.
truly incredible work you are doing here!
How does this work with corners? the air gap will obviously be rectangular in shape... I'm sure it's fine since that is the way most people cover their corners but I'm still curious
I’m thinking about moving blankets.
They are about 1/2 thick
Using 3 layers, one could stacks them 2,4 and 6 inches from the wall
I’ve got some GIK Acoustics panels, and they actually have around an inch of gap built in.
Also fellow Mitmensch mit male-pattern baldness wollt ich nur mal sagen: sieht rasiert richtig gut aus ;)
You articulate very well 👏 fair play, thanks!
Great work and well documented, I am definitely keeping your contact!
Thanks Jesco, for another informative video. I really appreciate you sharing this knowledge.
Why doesn’t the air gap apply to basstraps or does it?
Like placing a big 6x6 inch basstrap 6 inch from both corner walls?
Absolutely amazing content as always. Learning so much from these videos. Thanks for sharing. The channel should do really well going forward 👍👌
Did I get this right?… The green line representing the sound reduction of a gap less 100mm panel has a far more linear response with slightly wider frequency absorption range in the low end? If so, I feel the cost of the extra 50mm insulation is worth it.
I’ve chosen to go with a 100mm framed panel with 60mm depth of a more semi- rigid mineral wool board with 40mm of a less rigid lower density mineral wool board facing it.
Great video, thank you! To-the-point, and explained the 1-to-1 ratio of thickness to air gap very clearly.
I am currently about to build acoustic panels with 3.5” thick mineral wool insulation, so I’ll be planning on building stands for those panels so that they sit 3.5” away from the wall. I know it’s not 6 inches thick (which would be most ideal), but I also don’t have a lot of room for 6 inch thick panels in my home theater testing room that I’m building for my own channel. Not the most ideal, but better than no panels at all. 😁🤘 Thanks again! You have a new subscriber!
Hi! Would I be able to use some clips from this video in my own video about building out my own DIY acoustic panels? No audio - just me talking over some short clips from this video, since I want people to know where I got the science behind it. I reference this video a few times, so hopefully it’ll get more views too! Thanks! 😁
What if the 2” panel has wood panel on the entire back side? Will the air gap still be effective?
Having an air gap at all is a debatable topic. The issue of panel air gaps center around having an "open" air gap vs. a "sealed" air gap between the panel. Some have said that an open air gap may not do much acoustically. Looks like more numerical data is needed in the open vs. sealed debate. The documentation for the Porous Absorber Calculator does not make it clear whether the air gap measurement is based on open or sealed.
Using the Porous Absorber Calculator at the acousticmodelling link in the video, the half-wave dip in absorption you point out is much less of a problem when the calculator's Random Incidence option is checked. Does this imply that using pyramidal or triangular-ridged acoustic absorption foam is a better choice than flat-surfaced foam for deep air gaps?
Do you know how if panels would be any good for impact noise coming up the walls?
I just came across this video, what an excellent explanation thank you! I have 1 follow up question, so for example assuming a 2" sound absorbing panel and a 2" air gap, would a 2" thick Rockwool inside of a 4" deep frame, mounted flush to the wall, still be the same as a 2" deep panel, mounted 2" off of the wall?
How would you implement the air gap ? I've got several 6'' porous absorbers and would love to raise my absorption coefficient from 0.4 to 0.6 at 100 Hz as thats exactly the problem-frequency-band of my room.
I just don't know what's the best way to implement the gap.
Would be great if you could do a hands on video how you'd install a gap like that.
cheers from austria :)
I cut four 1.5" cubes of rigid foam (the white shiny stuff that's often used to package electronics) and hot glued them to the back of my (DIY, 7" thick) rockwool panels, then re-hung them using picture frame wire. The blocks are glued a few inches in from the corners, so they aren't visible. Now the panels sit securely on their four 'feet', and appear to be floating away from the walls... a nice look that would be even more awesome with some wall-washing LEDs added to the panel backs. The panels are nothing but double-thick rockwool sheets sewn in a fabric casing with either a minimal wooden frame on the back (new ones) or a solid sheet of thin MDF (early ones), so they're rigid enough and weight isn't an issue. I also made a 3.5" thick ceiling cloud using a back frame (with a bit more structure to it, and some buttons to hold things together) and hung it a few inches below the ceiling. I did this more to facilitate installation than for any audio benefit, so it's nice to hear that's added.
I see that the software includes the phrase "rigid backing"... I'm assuming this means a solid back like a sheet of thin plywood or MDF board, versus a sparse frame and fabric. Does this backing make a huge difference in performance?
Really interesting video, thanks for the calculator! Would be keen to understand if it is possible to do similar measurements with a flat panel in a corner where the depth is then not just a fixed amount, instead deeper in the middle than the edges.
Hi Jesco, I've seen this on an acoustic website and it's completely thrown me re the gap behind a panel. Can you throw any light on this?
NWAA Labs, Inc
2017 ASA NOLA
Absorption
Myth: Wall mounted panels that are spaced
off of the walls will increase their low frequency
absorption as the space behind increases.
Fact: This is only partially true. The low frequency
absorption only increases when the spacing from the wall
does not exceed 1 inch. The effect disappears after 1 inch.
This only applies to unimpeded airspace.
And what about bass traps? should there be an air gap too?
Good video and the PDF was an interesting read. My studio is visually a mess but sonically I'm delighted. Gradually I am tidying the room but the question is, how much harm will tidying the room do to the acoustics? I'm seriously considering putting up drapes to simply hide the cluttered shelves! 😀
Curtains will over the shelves will absorb too much high frequencies. Would be better off just moving all the shelves to another room or a storage cupboard.
How much thickness should be the rock wool? 50 mm vs 100 mm? 2 vs 4 inches?
Hi....my bass sweet spot is above the speakers 2-3 feet in front of the sitting spot (equilateral triangle). How to address this ... please help
Thanks for your awesome content! Very well explained and easy to digest even not having a lot of upfront knowledge.
Is this (in a more moderate way) also applicable to living rooms where you listens to music and want to treat the room? I‘m thinking about the wall behind the speakers and basically building a big wooden frame with Pamela’s you find in centralized concert rooms and put absorption material behind sand possibly an airspace. In the living room I‘d not make this deepen than 10cm though as it would otherwise interfere to much with the room and it‘s usage as a living room
Is this result due to the fact that you are moving the panel closer to the speaker?
Great channel, subbed and checking all your other videos :)
I have a question though, going to build new panels soon, (200mm depth cotton wool) but i'm never quite sure which density would suit my needs. Any info on that ?
What if I have airgaps between foam layers?
Ok, so now after watching the GIK Acoustics video on Air Gaps, it's pretty clear now that air gapping is really not a good idea unless you are doing extensive frequency testing and you know exactly what you are doing. If you are trying to float a 2" panel an inch or two off of the wall, then it's better to just use a 4" panel flat on the wall. And if you feel like you need to float a 4" panel off of the wall, then it's better to move up to a 6" panel flat on the wall. It appears that... yes, a "sealed" air gap is better than a open air gap, and an open air gap can make your situation worse if you aren't doing serious frequency measuring. Performance-wise it's better to just use a thicker panel flat on the wall over a thinner panel with an open air gap. It also looks like most GIK panels come with an air gap in the back portion of the frame, but it's also sealed with an acoustic cloth cover. Also in smaller rooms, it's almost automatic that you should be using 4" thick panels instead of 2" panels.
Now how the heck to mount my 6" panels a few inches off the wall
a grid of 1x2 from home depot.
@@mikets42 I figured the same thing. Couple painted 2x3s did it
Always excellent and applicable information, Jesco. :)
Best video on the internet
I hit the download link, but I didn’t get an email. Checked spam and junk folder too!
Good video, great channel. thanks for the advice.
Thank you! Great presentation. Question: we are getting repetitive bass sounds...day and night constantly from neighbors...! We have dual pane windows and dampers. Could bass be traveling via our plumbing? We love music...but what can we do on the entire length of one side of the house??? We live on a corner and basically have six neighbors. Echo effect probably plays a role? Any suggestions welcomed. Jim
That’s why I’m here. It’s insane on the neighbors alll day and alll night. They never stop.
Hi..... thanks for the video ... when making panels with rockwool . how to make sure you don't have any loos fiber in the air for health problems ?
Amazing content as always. Thx Jesco!
So does this same principle apply to the actual furniture in the room too example small side board pulled 1 inch from the wall instead of being pushed right up against the wall ?
While calculating, flow resistivity varies with the product?
would love to see a graph for thicker panels
Using a 6" Velocity traps placed 6" off the wall will begin to effectively trap bass. What does it do to the mids and highs? How much of the mids and highs do we want to remain active in the room? To place a 6" panel 6" off the wall, do you want air flow behind the panel (see right through from side to side along the wall) or can you increase the depth of the frame to the sides and top and bottom rest flat against the wall while the air gap exists between the wall and the inner core? Many Thanks! Great video!
If you want to retain mids upward, then face the velocity trap with Visqueen type plastic.
Measure to determine and achieve balanced room decay times.
Just out of Curiosity, is there any benefit observed if the panel is mounted like a wedge, for example, closest to the speaker has some or no air gap, with furthest away having the opposite property?
Great video, great channel. Thank you.
Can you please let us know, when we use rockwool "sound n safe", what standard gap should we have with it? Please.
hi , thanks alot for your help , i checked the site and i have a question , what if we use 2 layers of 4 inch panels each one with 4 inch air gap ? does it work ?
It would be good, if a series on home theatre can be made
Could you please explain why do you suggest caring about base traps while for the same money you can cover 2x (or 3x) of wall space with thinner foam for the same money? The low band of human ear directionality (phase-sensitive) is centered around 500Hz, and covering down to 300Hz (with an air gap, on -3dB) may appear to be more beneficial than going into huge room-eating expense with base traps (which you can eq electronically for a rather wide sweet spot).
Thanks for this!
What about corner bass traps. Floor to ceiling or is a 4 footer somewhere in the middle ok?
Floor to ceiling
Could you increase the density of the foam rather than move it away from the wall? Thanks.
Love the channel, been binge watching, about to build a studio in my guest house.
Hypothetical question, just out of curiosity:
How would a multiple panel/gap "sandwich" combination compare to single panel/gap of equal total thickness?
Lets say we cut a panel in half by thickness, and use it with half the gap between the wall and first panel, then another equal gap between panel one and two. Would that affect absorbtion in any meaningful way?
Taking it further, would a increasing/decreasing or shuffled thickness/gap multilayer sandwich make any perceptible difference?
Lets say | is one unit thickness, and space is a unit gap, something like:
room||| || | wall
We have 25 ft ceilings and an echo problem and would like to make decorative acoustical panels on one wall. If they are 2 in deep how large should the air gap be for normal conversation
Using the calculator, what would be the ideal look of that graph? Not sure that makes sense. I have 8 2ft x 4ft panels each one is 6 1/4" think with about 2 inch gap behind. Five are on the wall and 3 are on the ceiling. I like the sound but haven't measured it to find out what it sounds like.
Does the same go for when hanging panels overhead as a cloud? Distance fro panel or cloud to ceiling?
Perfect video, thank you verty much
Great video. One question I have never seen. If you use a 3” foam and make it real long. Hey let’s say rapping all your ceiling perimeters. Will it equal to just less 6” deep foam. Or is it the depth of the material that matters. Cube inches in a different way. 🤷🏽♂️
I don’t think so. You’re talking about reducing the energy of the sound wave. So it’s linear in the path of the wave. The video talks about putting that 3” foam 3” off the wall, which could get you similar results. But if you had a room and covered one wall with 6” of foam and the opposing wall with no treatment, i think it would be different than 3” of foam on both walls.
What if you were to use 2 panels simultaneously. Both in the same space but one with no space and a second with a gap. What would the graph show?
Cool video, thanks, greetings from far Chile.
Don't NEED it but if it's an absorber and you want it to work better; then yes.
Thank you, man!
bro i have a question, i just installed Rockwall AP , i want to know is it safe to breath around them on the studio as i cant breath very well on the room. did you hear about any breathing problem could happen or cancer casing effect on keep rock wall panel around you. thank you
Well explained
Thank You, Much appreciated