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ACDA-12 Activated Carbon Diaphragmatic Absorber

(3 customer reviews)


Are you tired of muddy and sloppy bass in your room with bass notes masking your music into one big bloated mess? Want to mix without second guessing what you’re hearing? Then our Activated Carbon Diaphragmatic Absorber is for you!

You get:

  • The most powerful low frequency absorber available in the world today,
  • 100% absorption at 50 Hz., 63% at 40 Hz. and absorption all the way down to 30 Hz., all in a depth of just 16″,
  • Unprecedented attack and decay clarity in every bass note, so you can mix without second guessing,
  • A bass absorber that softens the mids and the highs,
  • A solid wood unit that stands 30″W x 60″H x 16″D,
  • Independently tested and predictable performance results as verified in this report by Riverbank Acoustical Labs,
  • Phone time with our Chief Acoustic Engineer so any questions can be quickly answered,
  • Expert placement advice so you can get the most out of your completed unit,
  • A 100% money back guarantee!
These units have special handling and shipping requirements, due to their weight and size. Please call us on 520-392-9486 or click HERE to contact us so we can assist you further.
SKU: 000010241 Categories: ,


Activated Carbon Diaphragmatic Absorber

Are you tired of muddy and sloppy bass making you second guess your mix? Tired of not connecting with your music the way you know it’s possible? Frustrated by the lack of an emotional connection with your songs despite investing a crazy amount of money into your amp, speakers and hi-fi?

Imagine being able to hear incredible bass separation and definition in every piece of music you play and enjoying the sound of your music coming to life as your mids and highs pop like you always dreamt possible. Imagine being able to experience crystal clear attack and decay in each individual bass note in every piece of music you listen to.

With the ACDA-12, you’re going to feel the power of every single bass note in a way that few ever get to hear. It’s that connection to the music which makes all the difference to your enjoyment of it. It’s the dynamics and separation of instruments with crystal clear clarity definition, which creates the spine tingling, hairs on the back of the neck sensation that you desire so much from your mixing efforts and music collection.

What’s Different?
I invented the ACDA 10 and ACDA 12 Diaphragmatic Absorber units because I was unhappy with all the current products on the market that called themselves low frequency absorbers as they were nothing of the sort. I wanted true separation of bass sounds below 100h Hz, where the real magic in bass happens, and nothing commercially available even came close to providing me with the sonic experience I craved.

So I took the low frequency absorber walls I had designed, built and tested over a period of 8 years for professional offices, and worked with my team on developing a free standing unit that could be moved around a room as desired. Within 2 years we had a rigid cabinet structure and design in place but I knew I needed a cabinet fill material that would compliment the cabinets performance if I was to achieve the performance level I needed to really tame room modes, not just pay lip service to the concept. My stroke of luck came when I discovered the activated carbon internal fill material quite by accident.

I was working late one night and was stood over the kitchen sink when I noticed the water filter light was flashing. Struggling to remove it, I decided to hit it with a hammer and out poured all these small black pellets. On closer inspection the pellets looked liked miniature meteors, each full of thousands of microscopic holes, so I realized that if these small granules were filtering water and air then maybe they would help filter sound!

Further research indicated that activated carbon has a huge amount of surface area per gram of material, 2,000 square meters in fact! And with all of this surface area packed into such a small amount of space, I now had the secret, powerful fill material ingredient that could provide the horsepower audiophiles and professionals require to manage bass energy effectively. 8 further years of research and development later I now give you the ACDA 10/12 units.

What Will You Experience?

  • You get pound for pound the most powerful activated carbon diaphragmatic absorber available, in a free standing unit, in the world today, which gives you unprecedented attack and decay clarity in every bass note, so you can mix without second guessing and enjoy your music like you never thought possible.
  • You get 65 lb’s of activated carbon, 7 layers of constrained layer mass damping materials and two front walls in your unit which means you will experience a well defined, low end so your mids and highs will pop at you making your entire listening experience far more enjoyable as you open up a whole new dimension to your music.
  • You get low frequency absorption from 30 Hz. to 100 Hz. which gives you attack, decay, definition and tonal qualities, that you won’t have ever heard in your music before because of the way your room gets in the way. You’ll hear exactly what you want to hear when mixing without having to second guess your mix because of your room.
  • You get a moveable unit which can be wheeled in and out of your listening room or control room which gives you the flexibility to use your room in more ways than one without complaints from your partner as you can still return the room to its other uses when required.

The effectiveness of the box is exponential, the larger the room, the more boxes you need. But in the end the result is nothing short of amazing! Once you introduce the absorbers into the room, the effects are noticeable immediately.

Joe Salvatto, Recording Studio Designer and owner of Salvatto Sound, New York City. Clients include 50 Cent, Billy Joel and many more.

With the sound absorber panels it’s changed my whole musical experience! It’s given me depth in my music listening. The musical experience alone is more listenable, the instruments sound more like instruments.

Bruce Hallberg, Audiophile for 40+ years.

acda 10 Activated Carbon Diaphragmatic Absorber Cherry wood image

Diaphragmatic Absorption:
Time Tested And Proven

1. Dual Front Wall – The front wall in all of Acoustic Field’s diaphragmatic absorbers is not just a single wall. It is a dual wall structure that has been designed to increase the rate of absorption by increasing the level of energy that is slowed down before entering the internal cabinet fill material. With a dual wall face that is designed with sympathetic vibrational technology in place and having both dual wall, front panels that are designed with the proper density and air space between them to insure maximum movement in sympathy with each other, greater absorption rates and levels are achieved. When sound pressure energy strikes this dual wall, front face assembly, it is slowed down by a factor much greater than a single wall.

More information about diaphragmatic absorption.

Diaphragmatic Absorption

New And Improved Diaphragmatic Absorption

2. Stronger and More Rigid Cabinet – Cabinet rigidity and density has been increased using multiple layers of materials with different densities to insure maximum cabinet rigidity, so that the front dual wall construction is encouraged to vibrate. Viseo elastic compounds are used between each cabinet layer to insure that vibrational energy is minimized from the cabinet itself.

How our diaphragmatic absorbers work.

3. Activated Carbon Lowers Cabinet Q Value – The internal cabinet fill of standard building material, mineral fibers, has been replaced with activated carbon. Activated carbon is a fancy name for charcoal. Activated carbon has a high degree of porosity which contributes to its high rate and level of absorption over standard building type insulation. The rates and levels of low frequency absorption created by Acoustic Field’s activated carbon diaphragmatic absorbers have never been achieved until now for a commercially available product.

Our ACDA-12 is our activated carbon, diaphragmatic absorber with low frequency absorption from 30 Hz. – 50 Hz. See our ACDA 12 Riverbank Acoustical Labs Testing Results for more specific performance information on our ACDA – 12. The face of the unit can be used to support one of our foam absorber thicknesses or one of our mini-diffusors in our MDP line. Units are designed with rigid side and rear walls and a dual wall, front panel construction that increases diaphragmatic action. The inside of each unit contains 65 lb’s of our activated carbon filters which increase the unit’s Q value through acoustical compliance enhancement (ACE). This activated carbon filter process is unique to low frequency absorbers and is patent pending. Solid wood and paint finishes are available. Each unit measures 60″ tall, 30″ wide, and 16″ deep. Each ACDA-12 unit weighs 225 pounds.

The ACDA -12 is our strongest performing product in a low frequency range that produces the most issues in 95% of existing rooms. It is designed to absorb at high levels with a 20% absorption capacity at 30 Hz., 63% absorption coefficient at 40 Hz. and a 100% absorption coefficient at 50 Hz.

We stand 100% behind our product performance levels so we are happy to offer a 100% Money Back Guarantee* if you are unhappy with the performance results, for any reason.

Enough With A Compromised Listening Experience

Other manufacturers didn’t think it was possible or worth the time and money going after the low frequencies we’ve gone after. They thought it was impossible to achieve in a free standing unit and, in some cases, changed the definition of low frequency so that their so called “bass absorber” performance matched their exaggerated definition. Well talk about moving the goalposts and trying to pull wool over people’s eyes. We aren’t having it and are calling it out now. Enough is enough.

Our low frequency absorption rates have been independently tested and verified by the World famous Riverbank Acoustical Laboratories. You can see their report here: ACDA 12 Riverbank Acoustical Labs Testing Results and the graph below shows the absorption levels verified in the report… Yes it’s true, the ACDA 12 absorbs 100% at 50 Hz. and does a great job all the way down to 30 Hz.!

ACDA-12 Absorption Chart

So if you’ve bought what you thought was a low frequency bass absorber and its not dealing with frequencies below 100 Hz., then you’re missing out on a world of incredible sounds and pleasure in your music. With the wrong room dimensions, you will actually not hear some bass notes at all, no matter how high you turn your system up! You might as well bury your speakers 2 ft underground such is the equivalent blurring of the sounds you’re missing out on in your music.

So avoid listening to thick and muddy bass for a minute longer. You’re missing out on so much more from your music than you could possibly imagine, which is no doubt leaving you frustrated by the sound from your expensive amp and speakers.

Act Now

As the exclusive designer and manufacturer of this product and technology you cannot buy it in any other store or on any other website.

This product is for serious recording studios, Audiophiles and home theater builders only. If you’re serious about wanting sonic perfection in your low end, then this is most definitely for you. Don’t live with a compromised listening room and room sound for a minute longer. Take action now, believe me, you’ll thank me for this, for years to come.

Thank you

Dennis Foley
Inventor & Owner of Acoustic Fields

Weight 225 lbs
Dimensions 30 × 60 × 16 in


There’s no one size fits all when it comes to room acoustics. Your room is unique to you. If you see acoustic treatment analysis calculators on other sites, that’s all about marketing but no function. You need a live engineer to look at your room because there are too many variables in play to have a one size fits all solution. And any company that provides a one size fits all solution are just selling a bunch of band-aids that aren’t going to solve your problem. We're offering a REAL and FREE acoustic treatment room analysis, conducted by none other than Dennis Foley, our chief acoustics engineer himself.

Please click the button below to get your FREE acoustic treatment analysis.

If you have any questions please check our FAQ or send us an email directly to info@acousticfields.com.

3 reviews

  1. Bruce Hallberg

    First of all, listening for long time periods of time was so fatiguing. It is so bright, there’s a lot of glass. I put in cork floors because I thought that would help and I really, really had space and glass and height and issues that I really did not realize I had.

    So with the sound absorption panels, it’s just changed the whole experience. It has given me depth in my music listening. It has certainly the bass is there, but I call it depth because I am not a big bass guy to begin with. But the detail, I do not like to use the word sound stage, but just the musical experience alone, it is more listenable. The instruments sound more like instruments. We can accomplish more with what I have than this bright brassy offensive sound, and what was interesting is that no matter what I threw at the sound, be it the amplifiers, the cables, pre amps, whatever, the results were always the same.

    Now do I think that I need some other treatments in the room as well? I do. And we are gonna address that. But I will tell you this, that after chasing the dream for 40 years, I finally bit the bullet and realized how important the room treatment, and where I am listening is.

    I do not want to trash anything I have here, but after changing the room, after getting the room in a position and in a situation where I can listen, my speakers that I just bought are not acceptable; it is not what I want in a speaker. I am sure it is what a lot of people do want. I am looking for mid-range, I am looking for listenability, I am looking for color and timbre in the musical instruments.

    Now with the room treatment, this does not have anything that resembles what I think is good music. I am not a rock and roll guy, I am not a deep bass guy, and these are perfect for those people. For me, it is awful. So now I really feel that I can settle down and really focus on okay, what is it about a speaker or a cable or an amp or pre amp, that will really give me the sound that I am looking for?

    And I realize before that I could never find that. Because I did not have the room. Or the acoustics that would tell me. And I again go back to the experience I had at the musical instrument museum here in town after going to concert after concert after concert, a guitar is a guitar, right? Wrong. Not until you hear a guitar or a voice that’s in a room that’s acoustically treated, it just changes your whole musical experience.

    You know, Dennis, I am an audio guy, started in 1972 with LS35A’s and stereo 70 and loved music, mostly classical, jazz, and you know, I’ve run the gamut over the last 40 years, chasing the dream between equipment and cables and power cords and you name it. But I finally at this point in my life realized that something was missing.

    We live here in Phoenix and we have got an incredible venue here called the MIM, musical instrument museum, and I’ve had the opportunity to go to a number of concerts there. And I finally through that experience realized that this room issue that everyone has been telling me about for 30 years is something to really reckon with and you know kind of the rest is history. I went online, started looking around, and all of a sudden I find a guy down the street and here you pop up and so that kind of developed a relationship from there.

    You know, I’ve got some good friends in the hi fi business here in town. So you know, I had them over and they were gonna help me with some cabling and the first thing they said when they walked in the house was “you can do whatever you want, but you gotta do something with this room”. Well, I looked around and I thought, it is either buy a new house, or I had to figure something out.

    And so here are guys who have been in the business for a long time and understand the stereo business and sound and the first thing they say is I have a problem with the room. So another kind of an aha moment for me. And again, that’s when I started searching and you know, I got in contact with you, and I knew that I had a real serious problem here that had to be solved before I was going to put another dime in anything mechanical, upfront speakers, cables, whatever.

    Well, the space in the room is bad, right now I have a pair of Usher B speakers with a mac amp and I am using a aesthetic phono pre amp and aesthetic pre amp and an auraura turn table from England. I am thinking about going to a horn speaker but the bottom line is at least now I understand what has to happen in the room as far as acoustics before I can even start listening to a new speaker or cabling or whatever.

    So what you see here is what Dennis has built. Sound absorption panels. It looks like a TV behind me, but it is not. You know I made a cover for the TV. And I’ve got two more cables and two more panels in the garage, so basically what happened was that through what he’s given me and what he built for me, I really begin to understand this whole issue of room and what happens and reflection and sound and honestly, I still do not understand it, but I do know what sounds good.

    Bruce Hallberg

  2. Joe Salvatto

    Hi my name is Joe Salvatto from Salvatto Sound. We are a company that specializes in boutique studios here in the New York City Tri-State area.

    I came across this product designed by Acoustic Fields. Its called the diaphragmatic absorber. I read about it and was very intrigued with its capabilities. I had the opportunity to speak with Dennis, it’s designer, and was convinced that it was definitely something we could use on our installations.

    It’s a rather small enclosure, 24″ x 48″, but it’s abilities are actually beyond my expectations. It has the capabilities to absorb frequencies down to the 30 cycle range.

    So far we’ve used it in one room and have the intentions of using it in our next two installations.

    Everything Dennis said it would do, its done and then some.

    I was happy to comply with the companies request which was, upon purchasing the plans online and also signing a non-disclosure agreement, we have to purchase the charcoal absorbers, which is the internal workings of the device, directly from them, which they actually provided to us with a rather timely fashion. It didn’t take too long.

    The effectiveness of the box is exponential, the larger the room, the more boxes you need. But in the end the result is nothing short of amazing. Once you introduce the absorbers into the room, the effects are noticeable immediately.

    This device has added a paint brush to my box that I never would have thought I’d be able to have in this small of an enclosure. I’ll be using them from now on and I’m sure once you get a chance to use them, so will you.

    This is Joe Salvatto from Salvatto Sound. Very nice to talk to you.

  3. Danny Wyatt

    This room was eight or nine months in the making but it’s the Acoustic Fields bass traps that really made this room sing. Now it’s really quite a musical room that’s the way I would put it.

    Because I’m in New York City, because I’ve been doing this for three decades, because I have a lot of Rockstar engineer best friends, you see them on the Mix Master Wyatt show, Chris Gehringer, Luca Pretolesi, you know all kinds of top engineers doing number one records in the country I get to move around some of the best rooms, really on the planet, and when they come up here they’re like “oh my gosh, this is amazing, you can hear everything in this room!”

    You can hear extremely well sitting in the client couch and its, you can hear amazingly well sitting in the mix position and we used to have something too where if you stood up you’d get a slightly different low frequency response that also has gone now.

    And I’m really happy to say, and I’m an endless fiddler, that it’s really in a place where I wouldn’t change a thing and when people come in, I had the musical director for Chris Brown’s world tour here yesterday who is out on Lady Gaga’s Monster Ball Tour, top, top producer musical director and he was like “this room sounds insane!” He was like “I haven’t heard a room sound as good as this in a long time”. And he gets also gets to walk in the top rooms.

    So I’m extremely happy with it. This room wasn’t done until the Acoustic Fields bass trap technology entered the room and then once we did exactly what was proposed by you Dennis the whole thing snapped into place.

    So I couldn’t, I really just, I couldn’t be happier.

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