Thanks Dennis.very instructive as always. My room is only 16 .5 feet by 10 feet by 7.5 feet..IAM in the process of putting those absorption and diffusion panels on the walls. My speakers are Wharfedale Evo 4.2. The room has some slap echo. The back wall has a large window and I close the drapes when listening to music Should I put the panels on the front wall behind the speakers ? Any other advice would be useful. Maybe absorption panels on the ceiling above the speakers ? I have large bookshelves on the side walls which covers the point of first reflectiom 😢
Without knowing the rate and level of absorption of your treatment, I will not be able to assist you. Placing diffusion and absorption panels without a strategy and performance parameters is a recipe for failure.
This man is a genius! Everytime Im watching one of his posts, it feels like 10th grade chemistry all over again! Barely hanging on by a thread, but slowly learning!
@@AcousticFields thank you, are there any resources or videos of yours you can point me in the direction of? This is something I definitely want to pursue. Thanks again
I just discovered your channel and I'm learning a lot. I'm almost finished my control room/basement reno and your videos are very timely and informative. Thanks!
Diffusion is a technology that will increase resolution and create a larger sounding room. It does this using the science of psychoacoustics. It also increase reverb times. In order to achieve maximum diffusion perforamance, you must have low reverb times, reverb must be equal and balanced throughout the room, and decay times must be linear with no spatial irregularities in room response. This is why you must have these requirements managed correctly with the proper rate and level of absorption before introducing diffusion. Diffusion can drain your bank account and make your room sound worse if the requirements are not met.
Hi! Just wanted to thank you for all of the work that have gone into making these videos. I'm writing my thesis on a subject that is somewhat related to sound and the subjective perceptions thereof, and as you can propably note from this comment already - I don't know a whole lot about sound. These videos have really helped me understand some of the more advanced laboratory results and academic texts that I've had to plough trough during my research. Thank you so much.
Ben Tyreman Thanks for your comment. Each prime number is fed into a formula that calculates the frequency spread for that prime number. If you have diffuser space and the required listening position to diffuser distance, you should choose a higher prime number for more frequency coverage. Thanks Dennis
Thats cleared up and answered many of my questions. I kinda guessed id need diffusion on my front and rear walls (maybe ceiling too) for an audiophile 2 channel situation with foam on the side walls and 2 or maybe 4 of your diy bass absorbers. Problem is my front wall is all window so i may have to settle for diffusion rear wall and heavy drapes covering the entire front wall. By the time i get round to doing the room hopefully your Acoustic Fields window blinds will be available to ship with my foam. Thanks again Dennis for another cracking video.
Lee Goodwin Hi Lee, Windows must be covered. I can think of no worse sound than the reflections from glass surfaces. It invades our middle frequencies where our vocals lie and that is sacred ground. I want no room surface interfering with my vocals. You can have the front end of your room be all absorption with diffusion on the rear wall. Try this set up for a bit and listen. Once you understand how much diffusers contribute to spaciousness, separation, and definition, you will then be better able to decide on ceiling treatment. The proof is in the listening. Trust your ears and heart. Regards, Dennis
Thanks as always for your valuable information. I have a doubt. If my listening position is closer to the back wall and farther from the front wall, I might use a lower P7 at the back and a P11 for the front for example. Thanks.
Every prime number sequence in quadratic diffusion has a minimum distance requirement from diffuser face to the listener's ears. With these two prime numbers, you must use 4 -5' to avoid phase. Make sure your reverberation times are balanced throughout your room response is as balanced as possible or diffusion will drain your bank account and make your room sound worse.
Thanks Dennis. I am working to set up a Project studio again, and highly appreciate all you pro's out there who also take time to educate us. I believe it also will make your services better known. It most certainly help make some better sounding productions, now that a large part of the music industry has been force to move in to small private places. Especially are those the artists who now also have to become producers, and set up working acoustic situations. Hopefully some of them make enought to buy some of your services and products as well. Personally I am buying a little at the time.
Hey I see many polystyrene diffusion panels online are they as effective as wooden panels, or can they even work let's say from 500Hz and up? Thanks for the video!
We have built diffusers from plastic and we have built and do build wood diffusers. For the frequency range that diffusers work within, wood produces the best tone.
M, In any small room, you must deal with the low frequency energy first and foremost. Diffusion will make your room sound worse without proper low, middle, and high frequency management.
The speed of sound is constant at certian atmospheric pressures. To determine the length of a frequency (wavelength), divide the frequency into the speed of sound. 1130 divided by 40 hz. = 28'.
I am trying to treat a small office for critical listening. It has wood floors and flat walls. I added absorption panels and a sound absorbing curtain to minimize the echo. This largely takes place in the front, as this is a near field setup. The majority of space is behind the speaker system. I want to add diffusion panels on the back wall to diflect any reverberating sound. Would this be proper use of diffusion?
Hello I hope you can give some advise of what should I use and where should I place them (acoustic panels) Here is my condition: I have a 3 x 2.5 metres of room and I intend to make a home studio recording. This room is located ahead to my carport. For vocal tracking, I'm gonna put some curtains on one of the room corner (U-shape curtain). Should I use 2 diffusers (on the front & back of my control desk) ? How bout absorption panel? How many should I use them? Last week I have bought 5 sheets of 120 x 70 x 6 cm Rockwool and I haven't using them since. Looking forward for your response and thank you before :)
QRDude software recommends sitting 3 times the longest diffused wavelength away. For a diffuser like this one, that would be 12'. Will sitting just 50% further than the longest diffused wavelength away return similar results? Why do you think the recommendations vary so much?
The recommendations vary because the people giving the advice usually have never built and tested the results. They just regurgitate what they have read in textbooks. We build and install quadratics and have for 30 years. We know how they work and what they sound like.
Could you share a bit about your opinion on the need for diffusion on the front wall for a critical listening room? I have a smaller 20’x18’x10’ room with superchunks in four corners and absorption for the RFZ. I am planning more absorption on the rear wall and diffusion, but my understanding is nothing is really needed in the front wall after all that (other than more bass trapping if I can). Have you made any videos discussing diffusion on the front wall?
R, You have to develop a sound strategy for what sound quality objective you wish to achieve. Every surface area within your room has a specific sonic contribution to the overall presentation. You must step back and develop your specific goals for the room then assign the proper treatment for your goals. Fill out the information in this link and let's take a look at the total room. www.acousticfields.com/free-room-analysis/
the distance from my listening position to the back wall is 12'. After doing the math, I calculated the lowest frequency that the diffuser could diffuse is 94 Hz. My question: how deep does the 'well' need to be? And what Prime Number diffuser will I need? Thanks.
My mistake Mr. Foley I mistakenly put my well depth setting it 9in, instead of 12.5 inches. after correcting the specifications the calculator says it will have a diffusion range of 501Hz-2260Hz. Should I then assume that if the mix position is over 6feet away it will diffuse from 282Hz-3385Hz? Thank you for imparting your knowledge experience
+Jose M It is important to follow the sequence as stated. You will have to experiment with distances for proper wave formation and execution without distortion. I would use 6' as a minimum start distance..
would you suggest diffusion or absorption for front & rear wall's 25 ft front to back for a studio recording space,i heard you mention diffusion on one wall & absorption on another would that work ? at the moment i have diffusion on the rear wall but no treatment on the front control room window wall,the ceiling is fully treated i also have side wall gobos,could i send you some pics
Hi Sean, Diffusion type, amount, and location is related directly to usage. Send me your information in this link and include photos of all surface areas. www.acousticfields.com/free-room-analysis/
You've probably answered this a lot, I've looked some though and didn't see it. I'm building a 16x12 room with 8ft ceilings. My listening position will be at 38% so about 6' (unless there is a reason it should be different), I plan on putting a diffuser on the back wall. How would I determine the size, prime and should I use absorption on the side walls only or diffuse there as well? Thanks for the vids.
Acoustic Fields do you have a video you could suggest for understanding which prime to use and which frequency to use? I'm new to diffusion in general. Thanks for the response.
@@AcousticFields Hi, can you explain why both surfaces must be the same prime number with shorter distances? Does this also apply if I have 2 dimensional diffusion on rear wall? Thank You.
Hi Acoustic Fields, Congratz for all your videos , good job ! I've 2 questions : - I've 4 diffusor with their lowest frequency at 860 Hz . So with your calcul we need a distance, between the listening position and the rear wall, of 6.5 feet but my distance is : 12.5 feet . It's ok too ? Because I don't have other possibilities. - What's the best height to place the diffusor on the rear wall ? Thanks in advance ! :)
i m a drummer just about finisching my home studio...my biggest question is were to put diffusers and absorbers...in relation of my sitting position . without destroyng the bass frequency and midd tones...ty ciao from holland
zippie41 Positioning of sound absorbing technology is dependent on room size / volume / source / amplitude. If you give me more information by filling out this room form, I can better advise you. www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/
Question Mr. Foley, I downloaded a QRD well depth calculator, I put in the specifications for a P-13 diffuser, with a 3inch well width, and a maximum well depth of 9 inches. After I got the results, the program said that I should expect diffusion from 695Hz-2260Hz. I believe you claim diffusion from 282Hz-3385Hz.Is you diffusion frequency response calculation assuming I'd have enough distance for the lowest frequency to form in the room(distance of wave+50%). Should I assume I just answered my question as I am writing this, if so thank you for the priceless advice advice
+Jose M Diffusion sequences should be calculated to achieve maximum frequency range within the given space requirements within the room. We just built a diffusion sequence for a client based upon a prime 43. I believe it was almost 3' deep. The room had the distances to achieve full wave formation down to 100 Hz.
hi...the distance between my listenin position and the back wall of my control room is 2 meters.what s the prime number of the diffuser i need? (i wanna treat 200-600hz ) thx
Hi Moustafa, You could use a prime 11 or prime 13. The prime 11 is 9" deep and the 13 is 12" deep. Use only in the vertical domain. Position so 50% of the diffuser is above ear height. Cover the total rear wall surface area.
If the diffusion well has a gradation of depth say from 1" to 2" will it not work in a more analogue manner rather than a digital manner with frequencies being quantised say 1" to 2"
Hi Graham, All music and sound is in the analogue domain. Diffusers are like speakers. They are designed with a specific frequency response for the intended usage. You must follow certain formulas when designing a diffuser just like you do a speaker.
Hello Dennis, as far as diffusers, do you like putting diffusers vertically, horizontally, or a combination of the two the most accurate room i've worked in they were vertical first then horizontal above (crescent moon studios, Miami) wish I could attach pic
Hi Jose, Placing quadratic diffusers in a vertical and horizontal array creates two dimensions of diffusion. Two dimensional diffusion is used when the distance from diffuser surface to listener is shorter than the requirements for a one dimensional diffuser. Distance for a one dimensional diffuser is required, so that the lowest octave band represented by the diffuser has time to run and spread out.
W, The room size and volume determines your usage. You must select a room size and volume that minimizes your low frequency modal issues and allows for enough distance for middle and high frequency reflections to be managed correctly. Critical listening is part of the mixing process.
Control Room : 8 ft ceiling, width 17 ft X 12 ft length We installed skyline diffusion on the side walls would you recommend I leave them there? I am going to do the same on my rear wall not the full wall but the first reflections off the back. I would like to also incorporate four units of the Activated carbon Diaphragmatic absorbers you all make .The idea would be two on my back walls (L R) as well as the side walls (L R) and add absorption, and two poly-cylindrical diffusers. for our front wall we have installed hanging baffles in it behind slotted wood .would this be overkill or is it even suitable for my application as a recording studio?
Hi ***** If you could fill out this form on our website and include photos that would help me analyse this fully for you: www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/ Please also include your phone number so I can call if I have any questions. Thanks Dennis
Thanks for the video. I realized after looking at diffusers online that I knew nothing about acoustic treatment, and your videos have helped a lot. I'm confused though by your formula. The formula is speed/frequency, and what is confusing me is the number you use for the speed of sound. I thought that the speed of sound was about 344 m/s, and in your formula you use the number 1132. I'm not sure where you got this number from; are you using a different system (imperial) for the measurement of the speed of sound?
Fastback Studios My pleasure. The distance discussed is from the diffuser to the listening position. Take the lowest frequency produced by the chosen diffusion sequence and add another 50% to that wavelength distance. I hope that helps. If you want some further materials I have a free ebook and private videos available here www.acousticfields.com/free-ebook which you are welcome to access. Anything else I can help with, please let me know. Thanks Dennis
Fastback Studios I answered your question in greater depth in last weeks Google Hangout. You can see my answer to your question here ruclips.net/video/0_A0J2MjM8k/видео.html Hope it helps. Let me know if I can be of further assistance. Thanks Dennis
+GAYA-STUDIO Think of all energy below 100 Hz. as low frequency. This is a good guide line frequency because problematic frequencies above 100 Hz. are easier to treat with less dense technologies. Frequencies below 100 Hz. need special methodologies.
Hi Dennis Foley. Thanks for this video. i have a question regarding a rehearsal studio of around 400 sq ft. it's pretty small and i would want my band to experience diffusion from most parts of the room as we would move around quite alot. Should i use a P-7 diffuser for a small room? also, i thought of using just 1 loudspeaker for the room as i think with the correct diffuser and absorption placement, the volume and quality would be good enough as we are only going through Mono and not Stereo. Do you think it's a good idea?
H, First, you must manage all low middle and high frequency energy through absorption. Diffusion will make your room sound worse if all frequencies not managed before diffusion. What absorption technology do you have in the room?
@@AcousticFields thanks for replying, Dennis. We plan to use either rockwool or fiberglass (2 inch thick) for the exterior walls, floor platform and ceiling and also frame it in woods (2 layers) which would help with the high and low frequencies i hope. We're on a really tight budget so these materials make sense for us now :/
Really appreciating your informative video posts, Dennis. I'm looking at putting one of these diffusers on the live room back wall (behind where I've been setting up drums for recording). Do I need to take into account this distance of 4' (/6') in terms of where I'm likely to place some of the (eg. room) mic's? For example, If I want to place a room mic back there near the wall sometimes, am I then better off building a large P7 diffuser (or a bank of them repeated alongside each other) with less depth than the P13, to avoid anomalies getting picked up in that mic? Or is this outweighed by the overall benefits in the room of having a deeper (say P13 or above) diffuser, and maybe just shield off the side of that mic from facing the diffuser? I hope that makes sense! THANKS! Evan
PS. My live room is 9m long, and 4.6m wide on those end walls. There are also doorways through one side of each of the end walls, but this QRD could potentially be up to about 2m wide, and sit from one edge, and into the centre area of the wall. And I do have enough space there to make it a deep diffuser if it is indeed advantageous to do so at this location. Ceiling height is just over 3.3 metres.
Hi EvLoutonian Thank you for the comments, much appreciated. In answer to your questions I would still stick to using the lowest frequency diffused as your starting point when using microphones. A vertically positioned quadratic diffuser will spread sound out in a horizontal fan like array of energy. This would be a 180 degree radiation pattern. With this wide spread, I would find a microphone that has the proper sound field recording configuration. To give that microphone a chance at that diffused sound field, I would use the lowest frequency distance as a start. You will never get it correct the first time. It will take 3-4 sample recordings. Yes, It appears that you do have enough width. I need some more information to best answer your question. Could you fill out the information in this link and send it to me. Sit in your listening position and take pictures of all 4 walls and ceiling. Attach those to form data. www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/ I will run the analysis and get back to you with the results. Thanks Dennis
EvLoutonian Hey, I went ahead and asked my colleague to ask me your question in this weeks Google Hangout. You can see my answer to your question here. I hope it helps: ruclips.net/video/6cod-x4EVw8/видео.html Thanks Dennis
EvLoutonian We aim to go live each Tuesday at 11am EST however of recent it has been every second Tuesday. You can watch it at that time on our Google Hangout page at plus.google.com/u/2/b/115055447156960092252/+Acousticfields101/posts Are you on our mailing list as I always send a link to the replay there? You can join it here and get my free ebooks and videos www.acousticfields.com/free-ebook Thanks Dennis
So if my listening position is 3ft- 4ft from the back wall, speakers 8ft-9ft away with a 14ft front to back distance (listening room). Would you recommend a prime 7 diffuser ? Room is W18' x H15' x L14' . Where can I buy my diffuser panels?
M, Two dimensional diffusion with 2' x 2' units starting at 2' off the floor and running to ceiling and across total width of wall. We can quote you costs.
Hi keith ed Quadratic diffusion is not stereo or mono. It is an acoustical instrument that manages boundary (wall) surface reflections by minimizing their strength. It gives you separation and definition of frequencies whether mono or stereo signals. I hope that helps. Please let me know if you have follow up questions as I'll be happy to help. Have a great weekend Dennis
Hi keith ed I answered your question on diffusion and the stereo/mono relationship in greater detail in yesterdays Google Hangout. You can see the part where I answered your question here ruclips.net/video/wj0o-R3VX54/видео.html I hope it helps. Please let me know if you have any follow up questions I can help with. Thanks Dennis
What would you advise me in a situation of playing music in a tunnel, where I cannot influence the properties of the walls, but I have to process my soundtrack and find the position of the speaker in such a way as to increase the intelligibility of the music. Even sacrificing a number of frequencies. In other words, will the equalizer help me here. My goal is rather recognition, intelligibility of music, than great sound quality. The low frequency standing waves really spoil my music in the tunnel where I have to play it. Больше информации об этом исходном текстеЧтобы получить дополнительную информацию, введите исходный текст Отправить отзыв Боковые панели
sorry for the last question Mr Foley, it was asked at the end of a 22 hour day, what I meant to ask was i there a site you recommend for accurate individual well depths and fin width,and spacing once again my apologies. best reference i've found was www.digitalaudiorock.com/cgi-bin/qrd.cgi, as QRDude: Quadratic Residue Diffuser calculator is frozen thank you
final question, if you have at least 6 feet from from the front of the diffuser to the mix position is there a well depth you would recommend for an 282hz wave or is it then become pretty much moot, dont mean to overwhelm with questions, used digitalaudiorock.com/cgi-bin/qrd.cgi as a guide
Hi Lou, It depends on the size and volume of the room, distance from microphone to sound source, and many other variables. It all has to be calculated. Here is a link to our free room analysis. Lets take a look at your room and then I can better advise you. www.acousticfields.com/free-room-analysis/
Hi Erik, You are welcome. If you want us to take a look at your room, fill out the information in this free room analysis link: www.acousticfields.com/free-room-analysis/
Just wonderful teaching as always. As a rookie u have been a god send. the only question I have are how why is amazon allowed to sell the clearly inferior, mathematically laughable products they have now.
@@AcousticFields well I have seen these products first hand...density is not one of the requirements. I have also been working on some deflection/absorption tech of my own using open cell foam and diy diffuser tech. honestly just biding my time until we get a bigger studio. right now we basically doing vocals in a yellow room status. I think I am close to having the 5 events I need for a field to occur.... if I can replace this glass with a panel system. where can I find examples? I cant wait till I have saved enough to just pay u guys for top notch sound rooms.
Ben Tyreman I answered your question re: doubling in size the QRD 13 diffuser in greater depth in last weeks Google Hangout. You can see my answer to your question here ruclips.net/video/_FTrpF4SYGg/видео.html Hope it helps. Let me know if I can be of further assistance. Thanks Dennis
thanks for responding to my question dennis, I really appreciate that, I'm planning on building some of your QRD 13 diffusors soon so thought I would ask, thanks for clearing it up
My pleasure Ben Tyreman Let me know if you have any questions during the build and I'll be happy to help. Please send over photos once your build is complete as I would love to see how you get on. Thanks Dennis
Great work! Thanks for the videos!
Thanks Dennis.very instructive as always. My room is only 16 .5 feet by 10 feet by 7.5 feet..IAM in the process of putting those absorption and diffusion panels on the walls. My speakers are Wharfedale Evo 4.2. The room has some slap echo. The back wall has a large window and I close the drapes when listening to music
Should I put the panels on the front wall behind the speakers ? Any other advice would be useful. Maybe absorption panels on the ceiling above the speakers ? I have large bookshelves on the side walls which covers the point of first reflectiom
😢
Without knowing the rate and level of absorption of your treatment, I will not be able to assist you. Placing diffusion and absorption panels without a strategy and performance parameters is a recipe for failure.
It's amazing that people worked all this out.
Yes it is. As I tell everyone, its just physics.
This man is a genius! Everytime Im watching one of his posts, it feels like 10th grade chemistry all over again! Barely hanging on by a thread, but slowly learning!
I was wondering how the values of the wells were determined?Great video, Im not sure if i missed something. thanks
It is a complex formula that uses prime numbers with residue theory.
@@AcousticFields thank you, are there any resources or videos of yours you can point me in the direction of? This is something I definitely want to pursue. Thanks again
I just discovered your channel and I'm learning a lot. I'm almost finished my control room/basement reno and your videos are very timely and informative. Thanks!
Glad to help!
Still best ever on Diffusion. This knowledge launched my (After Retirement) career and I'll just say thanks...
Diffusion is a technology that will increase resolution and create a larger sounding room. It does this using the science of psychoacoustics. It also increase reverb times. In order to achieve maximum diffusion perforamance, you must have low reverb times, reverb must be equal and balanced throughout the room, and decay times must be linear with no spatial irregularities in room response. This is why you must have these requirements managed correctly with the proper rate and level of absorption before introducing diffusion. Diffusion can drain your bank account and make your room sound worse if the requirements are not met.
Hi! Just wanted to thank you for all of the work that have gone into making these videos. I'm writing my thesis on a subject that is somewhat related to sound and the subjective perceptions thereof, and as you can propably note from this comment already - I don't know a whole lot about sound. These videos have really helped me understand some of the more advanced laboratory results and academic texts that I've had to plough trough during my research. Thank you so much.
Ben Tyreman Thanks for your comment. Each prime number is fed into a formula that calculates the frequency spread for that prime number. If you have diffuser space and the required listening position to diffuser distance, you should choose a higher prime number for more frequency coverage.
Thanks
Dennis
Thats cleared up and answered many of my questions. I kinda guessed id need diffusion on my front and rear walls (maybe ceiling too) for an audiophile 2 channel situation with foam on the side walls and 2 or maybe 4 of your diy bass absorbers.
Problem is my front wall is all window so i may have to settle for diffusion rear wall and heavy drapes covering the entire front wall.
By the time i get round to doing the room hopefully your Acoustic Fields window blinds will be available to ship with my foam. Thanks again Dennis for another cracking video.
Lee Goodwin Hi Lee,
Windows must be covered. I can think of no worse sound than the reflections from glass surfaces. It invades our middle frequencies where our vocals lie and that is sacred ground. I want no room surface interfering with my vocals. You can have the front end of your room be all absorption with diffusion on the rear wall.
Try this set up for a bit and listen. Once you understand how much diffusers contribute to spaciousness, separation, and definition, you will then be better able to decide on ceiling treatment. The proof is in the listening. Trust your ears and heart.
Regards,
Dennis
Thanks Dennis. Cant wait to get started. Its gunna be interesting moving foam an diffusers in different positions. The sad life of an audiophile :-)
also dont use foam its simply bad
Thanks as always for your valuable information. I have a doubt. If my listening position is closer to the back wall and farther from the front wall, I might use a lower P7 at the back and a P11 for the front for example. Thanks.
Every prime number sequence in quadratic diffusion has a minimum distance requirement from diffuser face to the listener's ears. With these two prime numbers, you must use 4 -5' to avoid phase. Make sure your reverberation times are balanced throughout your room response is as balanced as possible or diffusion will drain your bank account and make your room sound worse.
Thanks Dennis. I am working to set up a Project studio again, and highly appreciate all you pro's out there who also take time to educate us. I believe it also will make your services better known. It most certainly help make some better sounding productions, now that a large part of the music industry has been force to move in to small private places. Especially are those the artists who now also have to become producers, and set up working acoustic situations. Hopefully some of them make enought to buy some of your services and products as well. Personally I am buying a little at the time.
Hey I see many polystyrene diffusion panels online are they as effective as wooden panels, or can they even work let's say from 500Hz and up?
Thanks for the video!
We have built diffusers from plastic and we have built and do build wood diffusers. For the frequency range that diffusers work within, wood produces the best tone.
This was an outstanding video. I am in the process of moving into a new small space for my home studio. Thanks.
M, In any small room, you must deal with the low frequency energy first and foremost. Diffusion will make your room sound worse without proper low, middle, and high frequency management.
how did you get these figures of the speed of sound, and frequencies
The speed of sound is constant at certian atmospheric pressures. To determine the length of a frequency (wavelength), divide the frequency into the speed of sound. 1130 divided by 40 hz. = 28'.
I am trying to treat a small office for critical listening. It has wood floors and flat walls. I added absorption panels and a sound absorbing curtain to minimize the echo. This largely takes place in the front, as this is a near field setup. The majority of space is behind the speaker system. I want to add diffusion panels on the back wall to diflect any reverberating sound. Would this be proper use of diffusion?
Your problem is reverberation, not echo. Diffusion will increase reverberation times.
Hello
I hope you can give some advise of what should I use and where should I place them (acoustic panels)
Here is my condition:
I have a 3 x 2.5 metres of room and I intend to make a home studio recording. This room is located ahead to my carport. For vocal tracking, I'm gonna put some curtains on one of the room corner (U-shape curtain).
Should I use 2 diffusers (on the front & back of my control desk) ?
How bout absorption panel? How many should I use them? Last week I have bought 5 sheets of 120 x 70 x 6 cm Rockwool and I haven't using them since.
Looking forward for your response and thank you before :)
QRDude software recommends sitting 3 times the longest diffused wavelength away. For a diffuser like this one, that would be 12'. Will sitting just 50% further than the longest diffused wavelength away return similar results? Why do you think the recommendations vary so much?
The recommendations vary because the people giving the advice usually have never built and tested the results. They just regurgitate what they have read in textbooks. We build and install quadratics and have for 30 years. We know how they work and what they sound like.
Could you share a bit about your opinion on the need for diffusion on the front wall for a critical listening room? I have a smaller 20’x18’x10’ room with superchunks in four corners and absorption for the RFZ. I am planning more absorption on the rear wall and diffusion, but my understanding is nothing is really needed in the front wall after all that (other than more bass trapping if I can). Have you made any videos discussing diffusion on the front wall?
R, You have to develop a sound strategy for what sound quality objective you wish to achieve. Every surface area within your room has a specific sonic contribution to the overall presentation. You must step back and develop your specific goals for the room then assign the proper treatment for your goals. Fill out the information in this link and let's take a look at the total room. www.acousticfields.com/free-room-analysis/
the distance from my listening position to the back wall is 12'. After doing the math, I calculated the lowest frequency that the diffuser could diffuse is 94 Hz. My question: how deep does the 'well' need to be? And what Prime Number diffuser will I need? Thanks.
My mistake Mr. Foley I mistakenly put my well depth setting it 9in, instead of 12.5 inches. after correcting the specifications the calculator says it will have a diffusion range of 501Hz-2260Hz. Should I then assume that if the mix position is over 6feet away it will diffuse from 282Hz-3385Hz? Thank you for imparting your knowledge experience
+Jose M It is important to follow the sequence as stated. You will have to experiment with distances for proper wave formation and execution without distortion. I would use 6' as a minimum start distance..
would you suggest diffusion or absorption for front & rear wall's 25 ft front to back for a studio recording space,i heard you mention diffusion on one wall & absorption on another would that work ? at the moment i have diffusion on the rear wall but no treatment on the front control room window wall,the ceiling is fully treated i also have side wall gobos,could i send you some pics
Hi Sean, Diffusion type, amount, and location is related directly to usage. Send me your information in this link and include photos of all surface areas. www.acousticfields.com/free-room-analysis/
You've probably answered this a lot, I've looked some though and didn't see it.
I'm building a 16x12 room with 8ft ceilings. My listening position will be at 38% so about 6' (unless there is a reason it should be different), I plan on putting a diffuser on the back wall. How would I determine the size, prime and should I use absorption on the side walls only or diffuse there as well? Thanks for the vids.
Hi Evan, You could use a prime 13 for your front and rear walls. With short distances such as yours, you must stay with same prime on both surfaces.
Acoustic Fields do you have a video you could suggest for understanding which prime to use and which frequency to use? I'm new to diffusion in general. Thanks for the response.
@@AcousticFields Hi, can you explain why both surfaces must be the same prime number with shorter distances? Does this also apply if I have 2 dimensional diffusion on rear wall? Thank You.
Hi Acoustic Fields,
Congratz for all your videos , good job !
I've 2 questions :
- I've 4 diffusor with their lowest frequency at 860 Hz . So with your calcul we need a distance, between the listening position and the rear wall, of 6.5 feet but my distance is : 12.5 feet . It's ok too ? Because I don't have other possibilities.
- What's the best height to place the diffusor on the rear wall ?
Thanks in advance ! :)
i m a drummer just about finisching my home studio...my biggest question is were to put diffusers and absorbers...in relation of my sitting position . without destroyng the bass frequency and midd tones...ty ciao from holland
zippie41
Positioning of sound absorbing technology is dependent on room size / volume / source / amplitude. If you give me more information by filling out this room form, I can better advise you.
www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/
Nice Denny, Im curious about how the back chambers of each well are reacting ? Dampening or inverse wave function ?
A, Yes it can occur but I have never found it audible. To be safe - treat.
Distance from diffuser or wall it's mounted on? What about vertical height compared to sound source?
S, Distance is from the wall itself to your ears. Start the diffusers 24" from the floor and run up to ceiling.
Question Mr. Foley, I downloaded a QRD well depth calculator, I put in the specifications for a P-13 diffuser, with a 3inch well width, and a maximum
well depth of 9 inches. After I got the results, the program said that I should expect diffusion from 695Hz-2260Hz. I believe you claim diffusion from 282Hz-3385Hz.Is you diffusion frequency response calculation assuming I'd have enough distance for the lowest frequency to form in the room(distance of wave+50%). Should I assume I just answered my question as I am writing this, if so thank you for the priceless advice
advice
+Jose M Diffusion sequences should be calculated to achieve maximum frequency range within the given space requirements within the room. We just built a diffusion sequence for a client based upon a prime 43. I believe it was almost 3' deep. The room had the distances to achieve full wave formation down to 100 Hz.
hi...the distance between my listenin position and the back wall of my control room is 2 meters.what s the prime number of the diffuser i need? (i wanna treat 200-600hz ) thx
Hi Moustafa, You could use a prime 11 or prime 13. The prime 11 is 9" deep and the 13 is 12" deep. Use only in the vertical domain. Position so 50% of the diffuser is above ear height. Cover the total rear wall surface area.
If the diffusion well has a gradation of depth say from 1" to 2" will it not work in a more analogue manner rather than a digital manner with frequencies being quantised say 1" to 2"
Hi Graham, All music and sound is in the analogue domain. Diffusers are like speakers. They are designed with a specific frequency response for the intended usage. You must follow certain formulas when designing a diffuser just like you do a speaker.
If you are singing into a QRD 7, what distance should the singer be at?
Start at 4' then try 5 then try 6
@@AcousticFields Thank You. For male vocals, what depth QRD diffuser would use go with?
Hello Dennis, as far as diffusers, do you like putting diffusers vertically, horizontally, or a combination of the two the most accurate room i've worked in they were vertical first then horizontal above (crescent moon studios, Miami) wish I could attach pic
Hi Jose, Placing quadratic diffusers in a vertical and horizontal array creates two dimensions of diffusion. Two dimensional diffusion is used when the distance from diffuser surface to listener is shorter than the requirements for a one dimensional diffuser. Distance for a one dimensional diffuser is required, so that the lowest octave band represented by the diffuser has time to run and spread out.
How do you get the frequency for p 13, p 11 ,p 7 etc
Apply quarter wave theory to well depth and half wave theory to well width. The prime number determines the total frequency response.
So If I have a bedroom and i use it to mix my tracks and also listen to music, what am I after? A control room or critical listening
W, The room size and volume determines your usage. You must select a room size and volume that minimizes your low frequency modal issues and allows for enough distance for middle and high frequency reflections to be managed correctly.
Critical listening is part of the mixing process.
control room
I have a room 10 feet by 8 feet x 8 feet. I have a little room studio. Where do i setup a difusser front i have a window
What is the room usage?
Control Room : 8 ft ceiling, width 17 ft X 12 ft length
We installed skyline diffusion on the side walls would you recommend I leave them there? I am going to do the same on my rear wall not the full wall but the first reflections off the back. I would like to also incorporate four units of the Activated carbon Diaphragmatic absorbers you all make .The idea would be two on my back walls (L R) as well as the side walls (L R) and add absorption, and two poly-cylindrical diffusers. for our front wall we have installed hanging baffles in it behind slotted wood .would this be overkill or is it even suitable for my application as a recording studio?
Hi *****
If you could fill out this form on our website and include photos that would help me analyse this fully for you:
www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/
Please also include your phone number so I can call if I have any questions.
Thanks
Dennis
What are the primes?
A prime number is divisible by itself and 1. Primes used in quadratic diffusers are 7, 11, 13, 17, 19, 23.
Thanks for the video. I realized after looking at diffusers online that I knew nothing about acoustic treatment, and your videos have helped a lot. I'm confused though by your formula. The formula is speed/frequency, and what is confusing me is the number you use for the speed of sound. I thought that the speed of sound was about 344 m/s, and in your formula you use the number 1132. I'm not sure where you got this number from; are you using a different system (imperial) for the measurement of the speed of sound?
S, 1132 is ft. / sec.
Ok got it.thank you very much.your lessions are very informative
Hey Dennis, thanks so much for all of your very informative videos! Question: so is that 6' from the listening position, or 6' from the sound source?
Fastback Studios My pleasure. The distance discussed is from the diffuser to the listening position. Take the lowest frequency produced by the chosen diffusion sequence and add another 50% to that wavelength distance.
I hope that helps. If you want some further materials I have a free ebook and private videos available here www.acousticfields.com/free-ebook which you are welcome to access.
Anything else I can help with, please let me know.
Thanks
Dennis
Fastback Studios I answered your question in greater depth in last weeks Google Hangout. You can see my answer to your question here ruclips.net/video/0_A0J2MjM8k/видео.html
Hope it helps. Let me know if I can be of further assistance.
Thanks
Dennis
For me, minute 4:58 - "Critical listening, diffusion on the front and the rear walls".
Hi
How do I know the low & high frequency for my recording room.
i use the skyline diffuser program
thanx
+GAYA-STUDIO Think of all energy below 100 Hz. as low frequency. This is a good guide line frequency because problematic frequencies above 100 Hz. are easier to treat with less dense technologies. Frequencies below 100 Hz. need special methodologies.
Hi Dennis Foley. Thanks for this video. i have a question regarding a rehearsal studio of around 400 sq ft. it's pretty small and i would want my band to experience diffusion from most parts of the room as we would move around quite alot. Should i use a P-7 diffuser for a small room? also, i thought of using just 1 loudspeaker for the room as i think with the correct diffuser and absorption placement, the volume and quality would be good enough as we are only going through Mono and not Stereo. Do you think it's a good idea?
H, First, you must manage all low middle and high frequency energy through absorption. Diffusion will make your room sound worse if all frequencies not managed before diffusion. What absorption technology do you have in the room?
@@AcousticFields thanks for replying, Dennis. We plan to use either rockwool or fiberglass (2 inch thick) for the exterior walls, floor platform and ceiling and also frame it in woods (2 layers) which would help with the high and low frequencies i hope. We're on a really tight budget so these materials make sense for us now :/
Really appreciating your informative video posts, Dennis.
I'm looking at putting one of these diffusers on the live room back wall (behind where I've been setting up drums for recording).
Do I need to take into account this distance of 4' (/6') in terms of where I'm likely to place some of the (eg. room) mic's?
For example, If I want to place a room mic back there near the wall sometimes, am I then better off building a large P7 diffuser (or a bank of them repeated alongside each other) with less depth than the P13, to avoid anomalies getting picked up in that mic?
Or is this outweighed by the overall benefits in the room of having a deeper (say P13 or above) diffuser, and maybe just shield off the side of that mic from facing the diffuser?
I hope that makes sense! THANKS!
Evan
PS. My live room is 9m long, and 4.6m wide on those end walls.
There are also doorways through one side of each of the end walls, but this QRD could potentially be up to about 2m wide, and sit from one edge, and into the centre area of the wall.
And I do have enough space there to make it a deep diffuser if it is indeed advantageous to do so at this location.
Ceiling height is just over 3.3 metres.
Hi EvLoutonian Thank you for the comments, much appreciated. In answer to your questions I would still stick to using the lowest frequency diffused as your starting point when using microphones. A vertically positioned quadratic diffuser will spread sound out in a horizontal fan like array of energy. This would be a 180 degree radiation pattern. With this wide spread, I would find a microphone that has the proper sound field recording configuration. To give that microphone a chance at that diffused sound field, I would use the lowest frequency distance as a start. You will never get it correct the first time. It will take 3-4 sample recordings.
Yes, It appears that you do have enough width. I need some more information to best answer your question. Could you fill out the information in this link and send it to me. Sit in your listening position and take pictures of all 4 walls and ceiling. Attach those to form data.
www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/ I will run the analysis and get back to you with the results.
Thanks
Dennis
EvLoutonian Hey, I went ahead and asked my colleague to ask me your question in this weeks Google Hangout. You can see my answer to your question here. I hope it helps:
ruclips.net/video/6cod-x4EVw8/видео.html
Thanks
Dennis
Acoustic Fields Thanks. I sent you an email.
I'm not much of a Google+ user.. How do I find my way to this GoogleHangout place / thing? THANK YOU!
EvLoutonian We aim to go live each Tuesday at 11am EST however of recent it has been every second Tuesday. You can watch it at that time on our Google Hangout page at plus.google.com/u/2/b/115055447156960092252/+Acousticfields101/posts Are you on our mailing list as I always send a link to the replay there? You can join it here and get my free ebooks and videos www.acousticfields.com/free-ebook Thanks Dennis
So if my listening position is 3ft- 4ft from the back wall, speakers 8ft-9ft away with a 14ft front to back distance (listening room). Would you recommend a prime 7 diffuser ?
Room is W18' x H15' x L14' . Where can I buy my diffuser panels?
M, Two dimensional diffusion with 2' x 2' units starting at 2' off the floor and running to ceiling and across total width of wall. We can quote you costs.
does diffusion enhance stereo or make it sound more like mono
Hi keith ed
Quadratic diffusion is not stereo or mono. It is an acoustical instrument that manages boundary (wall) surface reflections by minimizing their strength. It gives you separation and definition of frequencies whether mono or stereo signals.
I hope that helps. Please let me know if you have follow up questions as I'll be happy to help.
Have a great weekend
Dennis
Hi keith ed I answered your question on diffusion and the stereo/mono relationship in greater detail in yesterdays Google Hangout. You can see the part where I answered your question here ruclips.net/video/wj0o-R3VX54/видео.html
I hope it helps. Please let me know if you have any follow up questions I can help with.
Thanks
Dennis
Is there a specific reason diffusers are not diagonal?
Its all about surface area coverage. A square or rectangular unit is much more cost effective to build and position.
Thank you very much. Really useful.
Thank you sir.
K, Diffusion is such a powerful and not used technology I just don't understand the reason why. Diffusion sonic benefits are almost beyond words.
What would you advise me in a situation of playing music in a tunnel, where I cannot influence the properties of the walls, but I have to process my soundtrack and find the position of the speaker in such a way as to increase the intelligibility of the music. Even sacrificing a number of frequencies. In other words, will the equalizer help me here. My goal is rather recognition, intelligibility of music, than great sound quality. The low frequency standing waves really spoil my music in the tunnel where I have to play it.
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You must treat the low-frequency pressure issues regardless of the shape of the room.
@@AcousticFields but tonnel is very large. And I can't change the walls. Not permited.
It's a great video thanks
L, Thank you for your support.
sorry for the last question Mr Foley, it was asked at the end of a 22 hour day, what I meant to ask was i there a site you recommend for accurate individual well depths and fin width,and spacing once again my apologies. best reference i've found was www.digitalaudiorock.com/cgi-bin/qrd.cgi, as QRDude: Quadratic Residue Diffuser calculator is frozen thank you
J, Stay with the basic prime numbers for your diffusion sequences. You will not achieve audible performance differences using custom sequences.
final question, if you have at least 6 feet from from the front of the diffuser to the mix position is there a well depth you would recommend for an 282hz wave or is it then become pretty much moot, dont mean to overwhelm with questions, used digitalaudiorock.com/cgi-bin/qrd.cgi as a guide
J, Use a prime 13 sequence.
Where are diffusers placed in a live room?
Hi Lou, It depends on the size and volume of the room, distance from microphone to sound source, and many other variables. It all has to be calculated. Here is a link to our free room analysis. Lets take a look at your room and then I can better advise you. www.acousticfields.com/free-room-analysis/
Thanx
Hi Erik, You are welcome. If you want us to take a look at your room, fill out the information in this free room analysis link:
www.acousticfields.com/free-room-analysis/
Just wonderful teaching as always. As a rookie u have been a god send. the only question I have are how why is amazon allowed to sell the clearly inferior, mathematically laughable products they have now.
Q, Amazon is a private company and they can determine what they sell and what they do not.
@@AcousticFields well I have seen these products first hand...density is not one of the requirements. I have also been working on some deflection/absorption tech of my own using open cell foam and diy diffuser tech. honestly just biding my time until we get a bigger studio. right now we basically doing vocals in a yellow room status. I think I am close to having the 5 events I need for a field to occur.... if I can replace this glass with a panel system. where can I find examples? I cant wait till I have saved enough to just pay u guys for top notch sound rooms.
why prime numbers?
Primes are used in the basic modulus formula which is based in complex physics.
Ben Tyreman I answered your question re: doubling in size the QRD 13 diffuser in greater depth in last weeks Google Hangout. You can see my answer to your question here ruclips.net/video/_FTrpF4SYGg/видео.html
Hope it helps. Let me know if I can be of further assistance.
Thanks
Dennis
thanks for responding to my question dennis, I really appreciate that, I'm planning on building some of your QRD 13 diffusors soon so thought I would ask, thanks for clearing it up
My pleasure Ben Tyreman Let me know if you have any questions during the build and I'll be happy to help. Please send over photos once your build is complete as I would love to see how you get on.
Thanks
Dennis
Very hard to understand 😣
D, What specific question do you have?
Thanks!