Skip to main content

Low End Transformation

Hi Dennis,

I wasn’t sure how to re-establish communication with you. You helped me a few years ago with a room project and unfortunately I got sidetracked with health issues. It’s been awhile. Hope all is well. My health continues to improve and have been cancer free for quite awhile now. Still go in for treatment every 3 weeks though. The wife and I are very pleased with the results!

The wall is complete…finally (21 1/2′ X 9′ with 1000# of carbon)! I bought your plans for the diffusers and have a few already up. I can’t believe the transformation in the low end…unbelievable Dennis, unbelievable! I follow the videos you put up on UTube…very helpful, thank you. I have a plan of where to go from here with the diffusers but wanted to run it by you before building all of them. I can send you a summary of what I’ve accomplished so far in an e-mail or call…wasn’t sure because of the time passage.

Thank you for all your help in the past Dennis and I’m happy for your success in this field, you are very helpful to many people! I’m very impressed with your knowledge and expertise in the field Dennis, the results speak for themselves, I can attest to it! Not only to myself but folks who come over to hear the room/system!

John McAloon

– – –

Hi John,

Good to hear that you have won a victory in this battle. It could not have been easy.

Thank you for your kind words. Our carbon technology is now recognized throughout the world. I am glad you are now able to listen to definition and separation in the low end, something people for years just accept as not treatable. Nothing could be further from the truth as you have so stated.

Lets start from the beginning on your room. Fill out the information in this link: Photos of all surface areas are useful.

Diffusion is your next step. Adding diffusion with make your room sound twice as large. It will be like buying new speakers and new amps at the same time and auditioning them both. The difference between the electronics and the diffusion will be that you will like some things about the new gear and others not so much. With diffusion, you will like everything.

Dennis Foley

Save Your Money

Dear Dennis,

Thank you for calling me. I really appreciate you taking the time and effort to get involved in my particular problem.
It was great talking to you and you are truly insightful and have inspired me to get back in to physics!
I will save up for better acoustics and get back to you when I have.

Again, sending my deepest gratitude to you and your team for putting out all the great work and making information available for everyone.
I hope to collaborate with you in the future.


– – –

Dear Monisha,

Acoustic treatments are broken down into sections based upon their sonic impact for chosen usage. We have the front end of the room which includes the front wall with the adjoining side walls. The rear wall is a “system” all to itself depending upon usage. And the ceiling is another system that does many things. First, it can be treated to correct minor treatment errors done with front and side walls and secondly, it can be treated to maximize psycho acoustic perceptions by minimizing localization.

If budget does not permit treatment of of entire surface, it is best to wait and accumulate funds until you have the money to treat an entire surface area. Every surface area that is treated will high light the untreated surface areas and bring to light the need for more treatment. If you start with one surface area, and complete its treatment requirements, you will be motivated to finish after you hear the results.


Plan Far In Advance

My name is George and I have been watching your youtube series for a while and would like to use your treatment in the future. I have been slowly building up my equipment to have an awesome home theater one day, it’s been a lifelong goal of mine. In the next couple of years it’s looking like I will have an opportunity to build a house. Since it will be new construction I was wondering what size of room you think would be best for a home theater and if you have a guestimation of how much the acoustic treatment would be. I want to find out early on so that I can price things out and start saving up.

I have a few features that I want in the room that will probably mess with the acoustic. I want to have 2 rows of seating and have the 2nd row be higher than the 1st. The other feature is that I want to have the back of the theater be able to open up into the dining room so that if we have people over we can all the food and if people want to talk in a quieter area they can and still watch whatever is on. I do not have them yet, but eventually I will also have Dolby Atmos. I am thinking over all having a 7.2.2 sound system.

I personally like a bigger boom when listening to music or watching a movie. I like being able to feel the big moments. I live in Oregon, and have not been to any listening rooms before, so I don’t know if treatment takes that away or not.

Sorry if this was a little long and wordy. I just wanted to give all the details I could think of. Like I said earlier, if anything does happen it won’t be for a couple of years, and nothing is really set in stone yet. So if you have any other suggestions I would love to hear them, but the 2 specific pieces of advice I would like is your opinion on the size of the room and a ballpark figure of how much treatment may cost.

Thank you very much!

– – –

Hi George,

Planning well in advance in always welcome. It is much easier to move a line on a piece of paper then it is to move a wall. Choosing the correct room size and volume to match usage is critical. Sometimes a foot here or there can make a large difference in the amount and cost of low frequency treatment requirements. Once you have size/volume/usage calculated, you can then move towards addressing the noise/treatment paradigm.

Noise measurements must be taken over a seven day period. All frequency and amplitude issues must be measured. The barrier is then designed based upon those measurements. Noise/barrier technology can cost 3-4 times more than treatment, so the goal is to just do what is enough to reduce noise transmission based upon measurements. Treatment types, amounts, and positions can then be put into place. Let us know when you are ready to begin.We are currently 4 months out in taking on a new project. Please keep this time frame in mind.


First Dedicated Listening Room

Dennis, I sincerely appreciate and commend your clear, insightful and absolutely masterful videos on acoustic treatments. The way acoustic concepts interrelate and the methods applied to CORRECTLY TREAT room issues have always been a nebulous and abstract subject to me. And I’ve always ended up with more questions than answers after reading plenty of articles on the subject. Absolutely no one — and I mean no one — breaks down, examines, explores and, most importantly, explains the subject of acoustics for listening/recording purposes with the in-depth-crystal-clarity that you do. Your teachings have made me see and understand! My two, internationally released indie albums were tracked in pro studios. Now, however, I am setting up a place of my own where I can record at my own pace and at my leisure. Discovering your teachings comes at the perfect time in my life because I am just starting to set up my first-dedicated-room for professional recording! Best wishes to you, always!


– – –

Hi Bill,

Thank you for your support. We try and make the complicated simple and present it in a way that most can understand. Unfortunately, we have to work through much propaganda created by the industry to promote products that do not have the design parameters to accomplish the acoustic goals they are supposed to. Some classics are that foam is a low frequency absorber, egg cartons are diffusers, and building insulation is a good low, middle, and high frequency absorber. I forgot my favorite, that you should always place “bass traps” in the corners of rooms.

I recently received a call from an individual who purchased 10,000 in room treatment from Auralex. He installed the “bass traps” and was very unhappy about the sound of his room. After he spoke of the issues he was having, I asked him the dimensions of his room. They were 12′ x 12′ x 12′. A small coincidental room that was a cube. With these dimensions, his low frequency issues were exaggerated by up to 400 % and never had a chance of being attenuated. I asked him if they asked him his room size. They did not. They just kept telling him to add more absorption. Stay tuned for our upcoming video series where we show actual photos of client’s rooms and discuss the sonic out comes of those set ups.

Kind Regards,

DIY Diffuser Build Success

Thanks Dennis for all of your help with building a great, affordable , dedicated listening room in my basement! I read all that I could from your site and bought and built plans for diffusers. My low ceiling room went from blurrry audio to clean and precise. I spend 2 or 3 hours listening to music each day. It is such a pleasure.

After 25 years in the same home, we are looking at moving to another home. I will be re-establishing a great accoustical environment there. Of course there will be all this testing and treatment again but believe me, it is worth it! I will be viewing and participating often.

Thanks again for all of your help.


– – –

Hi Don,

Quadratic diffusion is such a wonderful technology but so misunderstood. People think that book shelves can be diffusers, plants spread sound out and act as diffusers, and who knows what else can diffuse sound. A diffuse sound field needs a device that can achieve a diffuse sound field with decay rates that are exponential and a host of other requirements. It takes a special tool to achieve that and quadratic diffusion is the only technology that can do that in small room acoustics.

Diffusion treatment is expensive and you must cover large surface areas. Along with large surface areas, you must have the correct distances to listening position for the diffused energy to fully form once it leaves the diffuser. Building the units yourself, reduces costs and achieves satisfaction in the build and the final listening presentation.

Thanks for you comments.

Guest Post


  • Recording studios market their expertise and equipment – but really sell their time.
    Flashy looking rooms help justify the rates and can inspire first time clients, but if you can’t consistently turn out great sounding recordings – in a timely manner, they’ll never come back.
    The proper treatment – especially low end treatment – is essential to long term success.
    Dennis, thank you for helping me turn the room you said needed to be burned down – into a fantastic sounding workspace for recording, mixing and mastering.
    Another thing we’re noticing is how long we can work without ear fatigue. You just don’t feel beat up after 10 or 12 hours in studio when the room is right.

    • Dennis Foley says:

      Hi Bob,

      Glad things are sounding better. If you get a chance and could video your studio set up for our audience, I know they would appreciate it. Highlighting what is different is a great start and helps many who are struggling. Ear fatigue is the result of the wrong rates and levels of absorption in the middle and high frequency range. That was one reason I created different rates and levels with our foam technology that more corresponds to the way we hear music.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.