@@AcousticFields yea, i caught that error, got distracted and had to restart the video to see what i had missed. math instructor here who teaches applications of quadratics and was real curious about this application i'd never seen before. nice video.
Thank you for taking the time! This is very useful as you are obviously measuring your room before you decide on how deep your wells should be. This is not a prime number QRD but the video still is very necessary because no one is explaining the math. Also the width of the well is just as important than the depth.
This is the first video I have seen of your channel, and I must say, well done sir. Efficiently described and presented. It is exactly the information I was looking for mathematically and your last minute of the video made me notice my need for this in my studio space.
Diffusion is a remarkable technology. Once heard people exhibit two responses. The first is regret that they did not find it sooner and secondly, they will never be without it again.
My pleasure Ken R Let me know if you have follow questions about anything in the video or if anything needs further explanation. I've already received some excellent questions on the back of this which will form the content of another video. So let me know if there were any additional questions you had on diffusion and I'll be happy to include in the follow up video. Thanks Dennis
Dennis, you said that the width of cells is derived from half wavelength. What wall, side or back, should be taken to define the standing wave needed and count its length correspondingly?
S, Let's step back a bit. Diffusion is a technology that can make your room sound worse if you haven't done some housekeeping first. Diffusion acts like a magnifying glass. It will magnify certain frequency and time signature issues you have not treated. You must first manage all frequencies below 100 Hz. with the proper low frequency absorption technology to control rate and level of modes. Secondly, your middle and high frequencies must have spectral balance and be evenly presented within your sound stage if mixing or listening room. Diffusion is like chocolate syrup on ice cream. You can only add it to the ice cream. You must have the ice cream first. Have you taken the above steps?
Hi Dennis, thanks for the interesting and informative video. A quick question for you: does it matter what material the diffuser is made from, assuming all else is the same? Is wood any different to, say, plastic, metal, or rigid foam, again assuming that all the diffusers are the same size etc.?
The well dividers that run vertically should technically be 1/8". That small wood is too fragile to work with and will warp over time creating phase issues. We use 1/4" for the vertical well dividers and 1/2" for the horizontal well dividers. Use cherry. Its worth the cost. Its the best wood for middle range (voice).
An 84 Hz. issue is a pressure issue not a reflection or reverberation issues. You must a lower frequency absorber such as our Carbon Panel. It stars at 40 Hz. and goes through 6,300 Hz. www.acousticfields.com/product/carbon-panel/
I teach acoustic also but I am nowhere nearly as good as you. Truth is I did take acoustic in my Music Production and Engineering program, not exclusively architectural acoustics. Many of your videos have helped me learn greatly and I can't wait to assemble a diffuser myself! A question though, are prime numbers something that tell me what frequency length this diffuser works with? Thanks so much!
Thanks for the great video as always. I have built your panels for several rooms with great success. Am trying to set up a small room and was wondering how far away from the diffuser panels does the listener have to be for them to be effective. In this case I am specifically talking about the qd7.
@@AcousticFields Thanks for the response. Unfortunately I don't see qd7, but I would imagine it's a little less than the qd11, but probably not much, so I can use that as a guide. Thanks.
My pleasure fibes1 Let me know if you have follow questions about anything in the video or if anything needs further explanation. I've already received some excellent questions on the back of this which will form the content of another video. So let me know if there were any additional questions you had on diffusion and I'll be happy to include in the follow up video. Thanks Dennis
Are you telling people that "fine wall art" is not the same thing???? I love these people who make "diffusers" without knowing the theories required to make it functional. Thanks for the video!!
To achieve a truly diffuse sound field in a small room, the technology must meet 5 rigid criteria of which decay rates and reverberation times are critical components.
Where are the ideal places to put diffusers (and in comparison to acoustic foam panels)? ie front wall, side walls, rear wall? Is there a rule of thumb or ratio for diffusers to absorptive panels?
Are space coupling diffusers good to use on a back wall when the listening position is close to the back wall? How thick should the the diffuser frame be? Should it be placed on the wall or extend into the room an inch or two off the wall?
Hi ***** I answered your question about what sound diffuser material you should use in greater depth in last weeks Google Hangout. You can see my answer to your question here ua-cam.com/video/a8MreTFkEXg/v-deo.html Hope it helps. Let me know if I can be of further assistance. Thanks Dennis
Hi Dennis, you say that the well depth is always 1/4 wave lenth hence the depths vary for the different wells due to different cycles they target. But how about the well width which you say is half wave length, the wells seem to be all having the same well width. Can you explain? And for a control room would you make the diffusion in the rear all with the same well depth or is it ok to make some with 6" and some with 12"? (not regularly distributed) Thank you very much for your really explanatory videos. Cheers, Caspar
The well depths are determined by a modula formula. The deepest well depth is the lowest frequency in the diffuser's response. The well width is the highest frequency in the diffusers' response. The well width is constant at half wavelength.
Because of this video I built two large panels using the QRD formula behind each speaker. I immediately noticed a wider soundstage but I’m missing height in the vocals. Do you recommend adding center panel? Vertical or horizontal? Thank you
For home theater room - if I place a P- 7 in the back wall so the seating should be 2 feet from the back wall? I came up with a number from your video "Sound Diffuser Placement - How To Position A Sound Diffuser"
The room only sees energy. It does not care about source or usage. Diffusion on the front wall of a two channel system will make the room sound larger if and only if you have met the requirements for diffusion.
Thanks for your videos. I've learned a lot from all your content and website. One question; Well Width often seems to be left out of most conversations about these diffusers. And the online quadratic calculators seem to give a very small width compared to the ones i've seen with my eyes. What would the Well WIDTH be for the example given in this video? Thank you.
There are performance restraints along with construction issues. If the well widths are smaller than 2", it is difficult for workers to get their fingers inside to secure pieces. A 2" width will provide diffusion out to 3,450 Hz. which is more than adequate.
You provide the well depths - but how wide is each well? On the real diffuser they look about 2 inches wide. Does it matter how wide they are? Do they all have to be the same width?
Well width is determined using half wavelength rules. Well width determines the upper frequency range of the diffusion sequence. Well depth is quarter wavelength. We use 2" wide widths due to construction limitations. This produces an upper frequency of 3,450 Hz. It is difficult to work in a small space for the well dividers. We have built them with 1" widths. If high frequency diffusion is required, we use another diffusion sequence which is our mini - wood diffusion sequence. www.acousticfields.com/mdw-mini-diffuser-overview/
@@AcousticFields Excellent, thanks. I've built my own diffusers in the past but just chose random depths, but the next set will follow your dimensions.
hello Dennis, wondering if this sound diffusers would be efficient to a meeting room. Without mecanic sound, only peoples voice and chats. Cause the frequency of the human voice seem to be below de 800Hz frequency low limit capted by this especific diffuser. Do you have any suggestion to this acoustic problem? greetings from Brazil
I would need much more information to assist you. Fill out the information in this link: www.acousticfields.com/guarantee/ Make sure you include photos of all room surfaces.
for that particular quadratic diffuser (prime 7 example?) would you just run one of those directly behind you or do you stack them side by side? if you do put them side by side what dictates the amount that you stack side by side (with the diffuser running vertically) and I guess the same question for running them horizontally?
Hi Christopher, Diffusion works best when you match the frequency response of the diffuser to the audio usage, distance from wall to listening position, and a host of other variables. Positioning them both vertically and horizontally provides two dimensions of diffusion. As a general rule, two dimensions of diffusion work better when your distances to listening position are below one dimensional requirements for a specific prime number diffusion sequence.
I have two questions. What kind of effect has diffuser on lower frequencis than the 1/4 wavelength. Let's say qd 13 has lowest diffusion frequency of 280 hz. What effect has it on 250 hz or 200 hz? Second question: Is it possible to have too much diffusion in listening room or home theather - can it become overwhelming or too live at some point, or is it a matter of taste? Thank You.
ill be building my BDA's in a couple weeks beginning with 6 units and im so tempted to build a diffusers just to get that real sound but alas, i have yet to meet the requirements to put them in place. Incidentally, is it proper to place diffusers on my front wall in front of all my BDA's?
Hey Dennis,i want to ask you if were to put quadratic diffusers in a 3mx4.60m wooden studio for drums only will they have any effect??if so what else do you suggest that i should put and where to position them exactly..i am thinking of putting two vertical on the opposite wall of the drums and one horizontal on the sealing.thanks for you time
Each prime number diffuser sequence 7 , 11, 13, etc. have a different lower frequency response. The well depth and width changes with the frequency response range. We use a 3,400 hz. top frequency.
Cheers Dennis. Another cracking video. Can we have a vid showing where you would ideally position the diffusers and what prime number combinations work best in relation to room size and room usage? Hehehe If you can fit all that in one video :-) Im guessing prime number 7 relates to the 1"+2"+4"=prime number7? Another question.....i know youve talked about symetry in regards to speaker positioning.......alcoves. how best to cover them when brickwork is not really possible. I was thinking 18mm mdf the whole wall but what do i infill the voids with? I was thinking a good solid frame of 100x50 timber behind. Lots of it to prevent it sounding like a drum. What do you think? I kinda know your going to say find a good bricklayer :-) is mdf and timber not really good enough as a compromise? Another :-) at college and uni we were told yellow insulation felt for heat and pink for sound. A method to provide a good barrier would usually be something like a 100x50 frame set 50mm away from the wall and packed with pink felt. Layers of felt behind the timber stud frame should wrap under and round the four sides so the frame was sat on the felt. Fixed with wedges so no screws into the floor walls or ceiling. Then boarded with foam backed plasterboard usually 10mm thick plasterboard with 20mm of foam. What do you think? Our acoustics lectures were a bit thin on the ground......think we had about 4 hours worth. We got as far as a 70db drill in a room +another 70db drill doesnt add up to 140db. We did learn how to calculate the true levels. A medium sized log equation if my memory serves me well :-) Cheers Dennis. Youre a diamond
As always, many thanks for the excellent questions adi daskoln I will put these on the list. I will try to respond to some of these questions in next Tuesdays Google Hangout. With the diffusion question, I think that warrants another video so will try to get that done ASAP. Thanks and have a great weekend! Dennis. P.S. How is the build going? Have you made a start?
K, The terms you are searching for are one dimensional and two dimensional. Positioning diffusers vertically only or horizontally only is one dimensional. When you combine both vertical and horizontal diffusion together that is called two-dimensional diffusion. One dimensional diffusion is used to create a larger sense of "space". Two-dimensional diffusion is used to reduce the impact of surface area reflections at shorter distances.
Hi Dennis. Am just setting up my project studio space and thinking before I get into diffusion and bass traps, I might cover the walls (presently sheets of wood panel over drywall) with planks of pine wood. Is it better for the room acoustics for the planks to be vertical or horizontal, or does it not matter?
RX, Neither. You can't guess about this or that for your music and voice room. Fill out the information in this link:www.acousticfields.com/free-room-analysis/ Lets take a serious look at what you are doing.
Hi Lahattec, Two dimensional diffusion can be combined into one unit but it is an expensive, time consuming, and difficult build. It is best to use both vertical and horizontal diffusion to create a two dimensional diffusion sound field.
Hey Dennis, Love you work. Question: I'm planning to buy the dynaudio bm15a for my homestudio. Option one is my bedroom The roomsize is about 15 square meters in total, and the height is 3,5 meters, and has the shape of a square. Option 2: The attic, size is about 25 square meters, height 4 meters, and has the shape of a triangle. Meaning the roofshape are not vertical. If you want i can send pictures of the 2 rooms, wich one would you choose? The speakers are known to be very good sounding but i'm wondering is it to big for my homestudio? Can i treat my room as such that they are a good fit in my room? Thanks Emir
+heeydado Use this room for sleeping only. Use the energy from a good night's sleep to find another room. Send me dimensions of the new room in this link. www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-room/
Thanks alvarofue Quadratic diffusion can be used in both large and small rooms. Quadratic diffusers have a much larger sonic impact in smaller rooms though. I consider them to be almost like a musical instrument when it comes to small rooms. Thanks Dennis
alvarofue I answered your question on the kind of rooms to use diffusers in in greater detail at the end of yesterdays Google Hangout. You can see the part where I answered your question here ua-cam.com/video/e02-NOaVyCU/v-deo.html I hope it helps. Please let me know if you have any follow up questions I can help with. Thanks Dennis
The diffusion pattern numbers 1 4 2 2 4 1 bear a similarity to the pattern for numbers for Pascal's Triangle. Can you talk a little bit about where to find more information on the theory behind this pattern, so I can dig further? Thanks in advance.
Hi. Im big fan of your videos and I have a question. Does this diffusers make difference to room sound pressure? Can i make better room frequency response with these diffuser?
Hi Han Lim The only diffuser that can make an impact on low frequency pressure issues is the QDA series www.acousticfields.com/product/qda-19-quadratic-diffusor-absorber/ which incorporates our carbon, low frequency absorption technology into the diffuser build itself. Freestanding diffusers only deal with middle and high frequencies. Diffusion will not have a direct impact on room response. You need to address unwanted room response issues with sound absorption technology. That said, you have bought our DIY BDA build plans and those will help with low frequency management. Please fill out the room analysis form on the following page so I can better advise you as to the numbers you need to build and their respective placement: www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/ Thanks Dennis
Hi Gino Punsalan Room treatment positioning is dependent on room musical usage. If it is a two channel playback system, then 12" off the floor for both front and rear wall is a good start. You will have to try different positions and test with repeated listening trials. Thanks Dennis
Hey Dennis, ive a question that pertains to how diffusers work/are effective. Someone told me youre not supposed to lacquer your diffuser - whats the science behind this reasoning? Also; how does that translate to paint - if i were to paint my diffuser, instead of using oil, do i just avoid anything that is "lacquer" and stick to mat, or is there a special kind of colour/base that i should be looking at? Thanks, Jan :)
Hi Jan Hajšen Soft woods produce the best tonal qualities in diffusers according to our testing. We have built diffusers out of many material types and find your soft woods such as alder, birch, and bass work well. We have even tried plastic injection molding and still go back to soft woods for their tonal balance. We finish with a clear coat to seal the wood from moisture and dirt.
HI My room is 20 feet length. 17 feet wide and 10 feet in height... what diffuser should i use... its a living room... with sofa fabric and wooden floor. it has curtains on both right and left. and both other walls front and back are brick smooth walls with paint. and concrete roof. Please let me know what all can i do...
+Atishay Singh Fill out the information within this link and I can better assist you. www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-room/
@@AcousticFields I'm your customer, Steve Drake, From San Jose. I'm the one with the guitar practice room who put a deposit on 600 lbs. of carbon recently.
S, Diffusion is a technology which makes a small room sound larger. They work well in live rooms that are small like yours. You will need a minimum of 2-4 units to allow for adequate square footage coverage.
E, Yes, energy is energy regardless of source. Diffusers take the energy that it is given and then spreads it out according to its designed frequency response.
Acoustic Fields honestly. How do you know exactly where to put them? Do you just take measurements with something like a dbx era-m so see the spectrum at different points on the walls? Then i can build diffusers to take care of the frequency range that is a little blown out?
Thank you for your videos. Have you seen the designs for quadratic diffusors which use frames that are hollow behind them rather than having solid walls between each well? These have an interesting aesthetic and they would be lighter due to less material. Something like this: ua-cam.com/video/cKc3M30ePuc/v-deo.html I am curious if there are implications to this design and the lack of wall between the wells.
+masterpangloss i believe you are referring to two dimensional diffusion. One dimensional diffusion has dividers and wells. Two dimensional diffusion does not. They are both acoustic tools that must be used to match the room usage and music processes involved.
@@AcousticFields No man, you're dope - love the channel! Just it was funny you said "Nine..." and stopped for like 700 milliseconds... you knew it was wrong lol
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
Thanks for this video! Although I am surprised that after 4 1/2 years nobody has pointed out that 9 isn't a prime number.
M, People are more focused on the total message without pointing out obvious errors.
@@AcousticFields yea, i caught that error, got distracted and had to restart the video to see what i had missed. math instructor here who teaches applications of quadratics and was real curious about this application i'd never seen before. nice video.
Thank you for taking the time! This is very useful as you are obviously measuring your room before you decide on how deep your wells should be. This is not a prime number QRD but the video still is very necessary because no one is explaining the math. Also the width of the well is just as important than the depth.
I try to watch all your videos because all of them are helpful . thank you ...
Glad to hear that
you helped a lot for my music experience project. thanks!!
You're very welcome!
This is the first video I have seen of your channel, and I must say, well done sir. Efficiently described and presented. It is exactly the information I was looking for mathematically and your last minute of the video made me notice my need for this in my studio space.
Diffusion is a remarkable technology. Once heard people exhibit two responses. The first is regret that they did not find it sooner and secondly, they will never be without it again.
Incredible knowledge in all of your videos
Dennis you always do a great job with your videos! Thank you so much for the time you spend on the videos and thanks for creating great products!
My pleasure Ken R Let me know if you have follow questions about anything in the video or if anything needs further explanation. I've already received some excellent questions on the back of this which will form the content of another video. So let me know if there were any additional questions you had on diffusion and I'll be happy to include in the follow up video.
Thanks
Dennis
Dennis, you said that the width of cells is derived from half wavelength. What wall, side or back, should be taken to define the standing wave needed and count its length correspondingly?
Looking to build a quadratic diffuser. This is such great information. Thank you Dennis.
S, Let's step back a bit. Diffusion is a technology that can make your room sound worse if you haven't done some housekeeping first. Diffusion acts like a magnifying glass. It will magnify certain frequency and time signature issues you have not treated. You must first manage all frequencies below 100 Hz. with the proper low frequency absorption technology to control rate and level of modes. Secondly, your middle and high frequencies must have spectral balance and be evenly presented within your sound stage if mixing or listening room. Diffusion is like chocolate syrup on ice cream. You can only add it to the ice cream. You must have the ice cream first. Have you taken the above steps?
Thank you for your hard work on these presentations!
Preaching the knowledge. Good stuff.
Diffusion is a wonderful technology if used correctly which in most cases that I see is not the norm.
I love watching your videos, thx for all the info you put out .
Its incredible how much I learned thx again.
Very helpful video by the way. Thank you
K, You are welcome. Thank you for your support.
Hi Dennis, thanks for the interesting and informative video. A quick question for you: does it matter what material the diffuser is made from, assuming all else is the same? Is wood any different to, say, plastic, metal, or rigid foam, again assuming that all the diffusers are the same size etc.?
Wood provides the best tonal qualities for mids and highs.
@@AcousticFields Thank you!
Best video ever. How wide should the wood itself be?
1/2 inch?
3/4 plywood? I want to use pine.
Alder and cherry are too expensive.
The well dividers that run vertically should technically be 1/8". That small wood is too fragile to work with and will warp over time creating phase issues. We use 1/4" for the vertical well dividers and 1/2" for the horizontal well dividers. Use cherry. Its worth the cost. Its the best wood for middle range (voice).
Thanks for this video! may I ask a stupid question? How can I reduce 84 Hz echo in my room?
An 84 Hz. issue is a pressure issue not a reflection or reverberation issues. You must a lower frequency absorber such as our Carbon Panel. It stars at 40 Hz. and goes through 6,300 Hz. www.acousticfields.com/product/carbon-panel/
@@AcousticFields Thanks a lot, sir! You saved my money and time!:)
Amazing! Great channel this.
Glad you enjoy it!
I teach acoustic also but I am nowhere nearly as good as you. Truth is I did take acoustic in my Music Production and Engineering program, not exclusively architectural acoustics. Many of your videos have helped me learn greatly and I can't wait to assemble a diffuser myself! A question though, are prime numbers something that tell me what frequency length this diffuser works with? Thanks so much!
C, The prime number determines frequency response. The well depth is calculated using 1/4 wave and the well width is calculated using 1/2 wavelength.
Hi, what is the proper displacement of quadratic diffuser in 12’x12’ room in relation of listening position? Thx
On average, you need to stay 4 -5' away from most prime numbers.
Thanks for the great video as always. I have built your panels for several rooms with great success. Am trying to set up a small room and was wondering how far away from the diffuser panels does the listener have to be for them to be effective. In this case I am specifically talking about the qd7.
www.acousticfields.com/diffuser-size-distance/
@@AcousticFields Thanks for the response. Unfortunately I don't see qd7, but I would imagine it's a little less than the qd11, but probably not much, so I can use that as a guide. Thanks.
Thanks for another awsome video.
My pleasure fibes1 Let me know if you have follow questions about anything in the video or if anything needs further explanation. I've already received some excellent questions on the back of this which will form the content of another video. So let me know if there were any additional questions you had on diffusion and I'll be happy to include in the follow up video.
Thanks
Dennis
So is it depth that matters most? Does width of the channels matter? Likewise does thickness of the wood matter?
Both the depth and the width of each well is critical.
Are you telling people that "fine wall art" is not the same thing????
I love these people who make "diffusers" without knowing the theories required to make it functional.
Thanks for the video!!
To achieve a truly diffuse sound field in a small room, the technology must meet 5 rigid criteria of which decay rates and reverberation times are critical components.
Where are the ideal places to put diffusers (and in comparison to acoustic foam panels)? ie front wall, side walls, rear wall? Is there a rule of thumb or ratio for diffusers to absorptive panels?
You must match the treatment locations and type to the room usage.
Any impact on the room sound with the high of the Q-Diffusor ? ... everything so far I have heard re is related to width and depth.
All diffusion sequences are based upon distance from diffuser to your ears. Each prime number diffuser has its own distance.
Are space coupling diffusers good to use on a back wall when the listening position is close to the back wall? How thick should the the diffuser frame be? Should it be placed on the wall or extend into the room an inch or two off the wall?
All quadratic diffuser placement is distance dependent. What is the distance from your ears to the wall?
@@AcousticFields about 12-18 inches. I gave a range because I've been experimenting with moving the couch off the back wall about 6 inches.
You need 4' minimum for any prime number sequence
Hi ***** I answered your question about what sound diffuser material you should use in greater depth in last weeks Google Hangout. You can see my answer to your question here ua-cam.com/video/a8MreTFkEXg/v-deo.html
Hope it helps. Let me know if I can be of further assistance.
Thanks
Dennis
Hi Dennis,
you say that the well depth is always 1/4 wave lenth hence the depths vary for the different wells due to different cycles they target. But how about the well width which you say is half wave length, the wells seem to be all having the same well width. Can you explain?
And for a control room would you make the diffusion in the rear all with the same well depth or is it ok to make some with 6" and some with 12"? (not regularly distributed)
Thank you very much for your really explanatory videos.
Cheers,
Caspar
The well depths are determined by a modula formula. The deepest well depth is the lowest frequency in the diffuser's response. The well width is the highest frequency in the diffusers' response. The well width is constant at half wavelength.
@@AcousticFields Meaning that for the P-7 diffusor in your video with the min. well depth of 1" the width is 2" for every single well?
great video dennis
N, Thanks for your support.
Because of this video I built two large panels using the QRD formula behind each speaker. I immediately noticed a wider soundstage but I’m missing height in the vocals. Do you recommend adding center panel? Vertical or horizontal? Thank you
You must cover the distance between the two speakers as a minimum. Its best to place diffusion on the complete front wall. Stay with one dimensional.
For home theater room - if I place a P- 7 in the back wall so the seating should be 2 feet from the back wall? I came up with a number from your video "Sound Diffuser Placement - How To Position A Sound Diffuser"
V, Start your P-7, 2 - D diffusion sequences at 24" off the floor and run the diffusion treatment sidewall to sidewall and up to the ceiling.
Usage is CRITICAL LISTENING with voice and percussion. Thx
Percussion instruments are actually classified as noise. Critical listening involves, voice, music, and noise.
So it would work good for an audiophile in their home music listening room?
The room only sees energy. It does not care about source or usage. Diffusion on the front wall of a two channel system will make the room sound larger if and only if you have met the requirements for diffusion.
@@AcousticFields ok, thanks!😁👍
Thanks for your videos. I've learned a lot from all your content and website. One question; Well Width often seems to be left out of most conversations about these diffusers. And the online quadratic calculators seem to give a very small width compared to the ones i've seen with my eyes.
What would the Well WIDTH be for the example given in this video?
Thank you.
There are performance restraints along with construction issues. If the well widths are smaller than 2", it is difficult for workers to get their fingers inside to secure pieces. A 2" width will provide diffusion out to 3,450 Hz. which is more than adequate.
You provide the well depths - but how wide is each well? On the real diffuser they look about 2 inches wide. Does it matter how wide they are? Do they all have to be the same width?
Well width is determined using half wavelength rules. Well width determines the upper frequency range of the diffusion sequence. Well depth is quarter wavelength. We use 2" wide widths due to construction limitations. This produces an upper frequency of 3,450 Hz. It is difficult to work in a small space for the well dividers. We have built them with 1" widths. If high frequency diffusion is required, we use another diffusion sequence which is our mini - wood diffusion sequence. www.acousticfields.com/mdw-mini-diffuser-overview/
@@AcousticFields Excellent, thanks. I've built my own diffusers in the past but just chose random depths, but the next set will follow your dimensions.
hello Dennis, wondering if this sound diffusers would be efficient to a meeting room. Without mecanic sound, only peoples voice and chats. Cause the frequency of the human voice seem to be below de 800Hz frequency low limit capted by this especific diffuser. Do you have any suggestion to this acoustic problem? greetings from Brazil
I would need much more information to assist you. Fill out the information in this link: www.acousticfields.com/guarantee/ Make sure you include photos of all room surfaces.
Nice video. In this case, assuming the highest frequency diffused is 3385 Hz, is the well width half of the wavelength of 3385 Hz signal?
S, Yes.
for that particular quadratic diffuser (prime 7 example?) would you just run one of those directly behind you or do you stack them side by side? if you do put them side by side what dictates the amount that you stack side by side (with the diffuser running vertically) and I guess the same question for running them horizontally?
Hi Christopher, Diffusion works best when you match the frequency response of the diffuser to the audio usage, distance from wall to listening position, and a host of other variables. Positioning them both vertically and horizontally provides two dimensions of diffusion. As a general rule, two dimensions of diffusion work better when your distances to listening position are below one dimensional requirements for a specific prime number diffusion sequence.
I have two questions. What kind of effect has diffuser on lower frequencis than the 1/4 wavelength. Let's say qd 13 has lowest diffusion frequency of 280 hz. What effect has it on 250 hz or 200 hz?
Second question: Is it possible to have too much diffusion in listening room or home theather - can it become overwhelming or too live at some point, or is it a matter of taste? Thank You.
V, Diffusion sequences have a frequency response. Frequencies below the design parameters are not diffused. Yes, you can overdue any treatment types.
ill be building my BDA's in a couple weeks beginning with 6 units and im so tempted to build a diffusers just to get that real sound but alas, i have yet to meet the requirements to put them in place. Incidentally, is it proper to place diffusers on my front wall in front of all my BDA's?
Hey Dennis,i want to ask you if were to put quadratic diffusers in a 3mx4.60m wooden studio for drums only will they have any effect??if so what else do you suggest that i should put and where to position them exactly..i am thinking of putting two vertical on the opposite wall of the drums and one horizontal on the sealing.thanks for you time
And what about Skyline Diffusor? Does it really work?
Skyline diffuser is the product name for a two dimensional diffuser. Two dimensional diffusion is widely used.
Does this repeat after the 1"? 1,1,4?
Each prime number diffuser sequence 7 , 11, 13, etc. have a different lower frequency response. The well depth and width changes with the frequency response range. We use a 3,400 hz. top frequency.
Cheers Dennis. Another cracking video.
Can we have a vid showing where you would ideally position the diffusers and what prime number combinations work best in relation to room size and room usage? Hehehe If you can fit all that in one video :-)
Im guessing prime number 7 relates to the 1"+2"+4"=prime number7?
Another question.....i know youve talked about symetry in regards to speaker positioning.......alcoves. how best to cover them when brickwork is not really possible. I was thinking 18mm mdf the whole wall but what do i infill the voids with? I was thinking a good solid frame of 100x50 timber behind. Lots of it to prevent it sounding like a drum. What do you think? I kinda know your going to say find a good bricklayer :-) is mdf and timber not really good enough as a compromise?
Another :-) at college and uni we were told yellow insulation felt for heat and pink for sound. A method to provide a good barrier would usually be something like a 100x50 frame set 50mm away from the wall and packed with pink felt. Layers of felt behind the timber stud frame should wrap under and round the four sides so the frame was sat on the felt. Fixed with wedges so no screws into the floor walls or ceiling. Then boarded with foam backed plasterboard usually 10mm thick plasterboard with 20mm of foam.
What do you think?
Our acoustics lectures were a bit thin on the ground......think we had about 4 hours worth. We got as far as a 70db drill in a room +another 70db drill doesnt add up to 140db. We did learn how to calculate the true levels. A medium sized log equation if my memory serves me well :-)
Cheers Dennis. Youre a diamond
As always, many thanks for the excellent questions adi daskoln I will put these on the list. I will try to respond to some of these questions in next Tuesdays Google Hangout. With the diffusion question, I think that warrants another video so will try to get that done ASAP.
Thanks and have a great weekend!
Dennis.
P.S. How is the build going? Have you made a start?
Sir would you use a vertical and horizontal at the same? What’s the norm?
K, The terms you are searching for are one dimensional and two dimensional. Positioning diffusers vertically only or horizontally only is one dimensional. When you combine both vertical and horizontal diffusion together that is called two-dimensional diffusion. One dimensional diffusion is used to create a larger sense of "space". Two-dimensional diffusion is used to reduce the impact of surface area reflections at shorter distances.
Hi Dennis. Am just setting up my project studio space and thinking before I get into diffusion and bass traps, I might cover the walls (presently sheets of wood panel over drywall) with planks of pine wood. Is it better for the room acoustics for the planks to be vertical or horizontal, or does it not matter?
RX, Neither. You can't guess about this or that for your music and voice room. Fill out the information in this link:www.acousticfields.com/free-room-analysis/ Lets take a serious look at what you are doing.
In theory could I cut all those numbers in half and it still be quadratic ? Example .5, 2,1,1,2, .5 ?
The goal is to provide a broad frequency range of diffusion. The higher the prime number the lower the bottom end of the frequency range.
@@AcousticFields gotcha ! Just wondering if in theory quadratic would still apply ?
I understand it would be for high frequency range
Hi Dennis, what's your opinion on fractal diffusers?
G, No opinion. They are another tool in our acoustical palette that favor higher frequencies.
What about combining horizontal and vertical in one diffuser?
Hi Lahattec, Two dimensional diffusion can be combined into one unit but it is an expensive, time consuming, and difficult build. It is best to use both vertical and horizontal diffusion to create a two dimensional diffusion sound field.
Hey Dennis,
Love you work.
Question: I'm planning to buy the dynaudio bm15a for my homestudio.
Option one is my bedroom The roomsize is about 15 square meters in total, and the height is 3,5 meters, and has the shape of a square.
Option 2: The attic, size is about 25 square meters, height 4 meters, and has the shape of a triangle. Meaning the roofshape are not vertical.
If you want i can send pictures of the 2 rooms, wich one would you choose?
The speakers are known to be very good sounding but i'm wondering is it to big for my homestudio?
Can i treat my room as such that they are a good fit in my room?
Thanks
Emir
+heeydado Use this room for sleeping only. Use the energy from a good night's sleep to find another room. Send me dimensions of the new room in this link. www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-room/
Very interesting!
Are these diffusers only meant for small rooms? Or are they also used in big spaces, like a music hall?
Thanks alvarofue Quadratic diffusion can be used in both large and small rooms. Quadratic diffusers have a much larger sonic impact in smaller rooms though. I consider them to be almost like a musical instrument when it comes to small rooms.
Thanks
Dennis
There's no big or small room for frequency nuisances.
alvarofue I answered your question on the kind of rooms to use diffusers in in greater detail at the end of yesterdays Google Hangout. You can see the part where I answered your question here ua-cam.com/video/e02-NOaVyCU/v-deo.html
I hope it helps. Please let me know if you have any follow up questions I can help with.
Thanks
Dennis
@@AcousticFields What is a small room? 3meter x 3meter would that work? Should I even bother trying to treat the sound in such a small square room?
The diffusion pattern numbers 1 4 2 2 4 1 bear a similarity to the pattern for numbers for Pascal's Triangle. Can you talk a little bit about where to find more information on the theory behind this pattern, so I can dig further? Thanks in advance.
+Joseph Dunphy You can find more theory back ground on diffusion in Peter D Antonio and Trevor Cox's book entitled Acoustic Absorbers and Diffusers.
Hi. Im big fan of your videos and I have a question.
Does this diffusers make difference to room sound pressure?
Can i make better room frequency response with these diffuser?
Hi Han Lim
The only diffuser that can make an impact on low frequency pressure issues is the QDA series www.acousticfields.com/product/qda-19-quadratic-diffusor-absorber/ which incorporates our carbon, low frequency absorption technology into the diffuser build itself. Freestanding diffusers only deal with middle and high frequencies. Diffusion will not have a direct impact on room response. You need to address unwanted room response issues with sound absorption technology. That said, you have bought our DIY BDA build plans and those will help with low frequency management. Please fill out the room analysis form on the following page so I can better advise you as to the numbers you need to build and their respective placement:
www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-about-your-room/
Thanks
Dennis
Acoustic Fields Thanks a lot! will do!
Hi Han Lim
And here's an answer to question on diffusers and room frequency response: ua-cam.com/video/agBfDIunFi8/v-deo.html
Thanks
Dennis
How tall should a diffuser be assuming it will put on the floor. How much of the front wall, for example, should be covered with diffusers?
Hi Gino Punsalan
Room treatment positioning is dependent on room musical usage. If it is a two channel playback system, then 12" off the floor for both front and rear wall is a good start. You will have to try different positions and test with repeated listening trials.
Thanks
Dennis
Hey Dennis, ive a question that pertains to how diffusers work/are effective. Someone told me youre not supposed to lacquer your diffuser - whats the science behind this reasoning? Also; how does that translate to paint - if i were to paint my diffuser, instead of using oil, do i just avoid anything that is "lacquer" and stick to mat, or is there a special kind of colour/base that i should be looking at?
Thanks, Jan :)
Hi Jan Hajšen
Soft woods produce the best tonal qualities in diffusers according to our testing. We have built diffusers out of many material types and find your soft woods such as alder, birch, and bass work well. We have even tried plastic injection molding and still go back to soft woods for their tonal balance. We finish with a clear coat to seal the wood from moisture and dirt.
What material are you making the diffusers out of?
Thank you
R, You are welcome.
Well Explained:-) Thanks
HI My room is 20 feet length. 17 feet wide and 10 feet in height... what diffuser should i use... its a living room... with sofa fabric and wooden floor. it has curtains on both right and left. and both other walls front and back are brick smooth walls with paint. and concrete roof. Please let me know what all can i do...
+Atishay Singh Fill out the information within this link and I can better assist you. www.acousticfields.com/free-acoustic-treatment-room-analysis-tell-us-room/
Where is the 7th well?
It is a 0 well which means no depth. It is flat to produce reflections. We have extended the frame to compensate and make the unit smaller.
thanks bro!
Hi, Dennis-
My room is 19' x 14' with an 8' ceiling-- not a big room. Is there any point in putting a diffuser in there?
S, What is your usage? remember every room usage has different acoustical treatment requirements.
@@AcousticFields I'm your customer, Steve Drake, From San Jose. I'm the one with the guitar practice room who put a deposit on 600 lbs. of carbon recently.
S, Diffusion is a technology which makes a small room sound larger. They work well in live rooms that are small like yours. You will need a minimum of 2-4 units to allow for adequate square footage coverage.
@@AcousticFields Thank you!
Does it work the same with planar dipole speakers?
E, Yes, energy is energy regardless of source. Diffusers take the energy that it is given and then spreads it out according to its designed frequency response.
Thanks. I appreciate your videos.
спасибо за субтитры!
We’ll talk about that in another video
J, Do you have a question?
Acoustic Fields honestly. How do you know exactly where to put them? Do you just take measurements with something like a dbx era-m so see the spectrum at different points on the walls? Then i can build diffusers to take care of the frequency range that is a little blown out?
how is 1132'/s divided by .33' --3385 hz and not 3430 hz
K, What is the main topic of the video?
@@AcousticFields right. Sorry. My bad. I just have OCD and i thought I'm going wrong. Thank you
Thank you for your videos. Have you seen the designs for quadratic diffusors which use frames that are hollow behind them rather than having solid walls between each well? These have an interesting aesthetic and they would be lighter due to less material. Something like this: ua-cam.com/video/cKc3M30ePuc/v-deo.html
I am curious if there are implications to this design and the lack of wall between the wells.
+masterpangloss i believe you are referring to two dimensional diffusion. One dimensional diffusion has dividers and wells. Two dimensional diffusion does not. They are both acoustic tools that must be used to match the room usage and music processes involved.
JAAJAJ 9 IS A PRIME NUMBER
AND THE EXAMPLE IS MOD 6 NOT MOD 7
COME ON
M, Don't waste oiur time commenting on an obvious error. What can you contribute to the discussion?
:)
9 is not a prime number
M, What is the topic of the video?
@@AcousticFields No man, you're dope - love the channel! Just it was funny you said "Nine..." and stopped for like 700 milliseconds... you knew it was wrong lol