How A Diaphragmatic Absorber Works - www.AcousticFields.com

[@Sentientfx1]

So refreshing to hear from somebody who really understands the subject. Thanks for posting!

[@AcousticFields]

Glad it was helpful!

[@vinjou2000]

at 2:58, when Dennis mentioned the cabinet has 65 lbs of Active carbon, and it should have a "low " Q value. Meaning high acoustic resistance/damping factor.

[@AcousticFields]

V, Yes, low "Q" value. Thank you for the correction.

[@Oneness100]

Dennis, When you talk about a diaphragmatic versus membrane absorption unit, what are the actual design differences that determine whether it's a diaphragmatic or a membrane absorption device? Is it the material of the diaphragm/membrane, is it the depth of the cabinet, the way the diaphragm/membrane is attached to the unit, etc. that determines to call it a membrane or diaphragmatic device?

[@AcousticFields]

O, Diaphragmatic has higher material densities than membrane. The diaphragm is denser with more mass. The cabinet is denser and using our carbon technology, you can achieve much higher rates using both types.

[@Oneness100]

@@AcousticFields Is there any differences to the front wall? Is one method more rigid and the other more 'flexible'? I'm just trying to figure out what a definition of either approach would be so that one could easily identify between the two. To me, a membrane would be a thinner "diaphragm" as the word suggests something along the lines of a drum head where the material flexes much more than a rigid panel. And a 'diaphragm' would suggest a more rigid material where it moving back and forth in sympathy with the external pressure.

[@dannyreed2887]

An air cavity like a "Boom Car" travels on rubber wheels and shakes up the whole town on it's way out of town. You can hear it for miles away. You can FEEL it.

[@calvinrocco4505]

pro tip: you can watch movies at Flixzone. Been using them for watching a lot of movies recently.

[@lucianoricardo598]

@Calvin Rocco yea, have been using Flixzone} for years myself =)

[@thaddeuskeanu8456]

@Calvin Rocco Yea, have been watching on flixzone} for since november myself =)

[@bobjencks4977]

Do you have frequency response and decay time before and afters of a problem room to show the effect of 1, 2, 3 etc of the diaphragmatic absorbers you sell?

[@AcousticFields]

B, Each one of our ACDA units attenuates 1.5 dB / 12 sq. ft. which is the surface area coverage/unit. Measure the impact of your problematic frequencies in dB SPL and then apply the 1.5 dB attenuation/unit to determine how many units required.

[@truhunk1]

It would have been nice if you had a real model to show.

[@AcousticFields]

C, You can see our diaphragmatic absorption process on our site or in this channel. The major difference between our diaphragmatic process and existing technology is the dual front wall (diaphragm), internal cabinet carbon which lowers "Q" value The carbon rapidly accelerates the rate of absorption within the cabinet. The resonant frequency is still controlled by cabinet depth.

[@badrini]

@@AcousticFields...and seven layers dampened

[@AcousticFields]

@@badrini The process you are referring to is called constrained - layer mass - dampening. You are using a series of layers of materials that are frequency and amplitude dependent that are constrained or assembled together to reduce vibration transmission.

[@leandromaseroni]

Hello, is there any update in the construction plan package or is it still the same link that you have left here?

[@AcousticFields]

www.acousticfields.com/product/all-in-one-diy-acoustic-treatment-build-plans-package/

[@richarddavis5542]

This is great basic information. Can these cabinets be tuned for frequency? I assume the thickness of the carbon membrane is for tuning for amplitude? I don't believe in one size for all. If I have 5 axile modes in my room between 80 - 30 hz will your build plans tell me how to tune/construct a DIY cabinets for those problem modes? (I expect to have multiple cabinets since the modes are between different walls).

[@AcousticFields]

The BDA / DIY units are the same performance of our ACDA-10 series. They are broadband from 30 - 300 hz for the lower end and the foam face extend the absorption to 6,300 hz.

[@electrorogue]

would it function as a coffee table as well ?!

[@AcousticFields]

Hi E, Yes, low frequency management is about providing enough surface area of the correct rate and level for room size and volume. However, placing a highly reflective device in front of you between source and receiver is not a good idea at all.

[@electrorogue]

That sounds very interesting, as I could spare the space for a coffee table behind where I work. My living room is my studio. so sofa and coffee table need to be there really.

[@AcousticFields]

E, Placing a coffee table in front of a listening position will produce spurious reflections that would interfere with the direct reflected ratio of energy presentation

[@eliaszerano3510]

what is the most effective way to treat a 30Hz node ?please?

[@AcousticFields]

Only diaphragmatic absorption will go that low and get enough.

[@tomeknaumann1338]

I am wondering if this kind of absorber would work with the first layers being curved? The arc being a stronger shape than a straight line would require the layers to be thinner yet rigid (metal sheets?) I would much prefer the whole unit to be a quarter of a circle (for estetic reasons only).

[@AcousticFields]

You are working with pressure waves that are 20' - 40' long. A curve here or there will have no impact on a pressure wave.

[@dannyreed2887]

Every contact point connection is going to conduct the wave. What if the Layers weren't connected and allowed to move? It's still not perfect. I use the "Boom Car"analogy.

[@laurentmussard9423]

Thank you so much Mr Foley for your incredible content. Your channel brought me to reconsider what I thought I knew about acoustics. I'm currently watching all your videos and the more I learn, the more I feel like my idea of bringing together the concepts of "living-room" and "home theater" is meant to abort. I'm willing to make compromises, but I really don't see how I could combine the acoustical requirements of a home theater room with those of a living room. 😥

[@AcousticFields]

L, Its not possible. Best to look for another room.

[@legitflavo3338]

How can I know when the treatment is enough or too much? Or it doesn't exist a "too much" treatment?

[@AcousticFields]

It depends on your usage and what you want the room to sound like.

[@ARGBlackCloud]

Very interesting design, the fact that your layering the outer cabinet with damping is a great idea. Wave transition through different media !! Love it. Keep up the great work, I still don't fully understand how the activated carbon produces a high net wave absorption, is it due to particle size and mass ? Cheers Richard

[@AcousticFields]

A , Wave absorption is all about pressure. We reduce the pressure inside the cabinet so when the wave enters it is faced with a lower pressure environment.

[@Cinqmil]

Can it be used to absorb infrasound vibrations?

[@AcousticFields]

Hi Cinqmil Diaphragmatic absorbers are designed to have a resonant frequency that meets some designed for parameter. Frequencies above that designed for resonant frequencies are absorbed those below are not. Thanks Dennis

[@badrini]

Maybe increasing the density of the front diaphgrams and the depth of the cabinet

[@Velghe87]

Great video, but am I the only one who thinks it’s a bit funny your instruction room is very reverberant? 😀

[@AcousticFields]

If you focus your attention on content rather than presentation value, you will always come away with some learning and understanding. Is that your goal?

[@Velghe87]

@@AcousticFields Dude... it was just a joke... and yes I bought your DIY plans. Cheer up man.

[@AcousticFields]

What do you plan to do with DIY plans?

[@Velghe87]

@@AcousticFields Treating my home recording studio with acoustics.

[@abletontechniker2311]

Really great videos! I have some questions... Where can i get data of activated carbon or what do you use to calculate the absorbers? Whats the volume mass of activated carbon? Can you send me some data of this interesting material for acoustic treatment? But this looks interesting because of the two plate resonators tuned to different frequencies with the activated carbon included. really really good idea! i like that. Im from germany and we use other technology here (all firesafe) . Can you give some information to me about this kind of technology?

[@AcousticFields]

A, Our carbon technology is proprietary. We manufacture it ourselves to control porosity count, size, and density. Activated carbons used for water and air filtration will not work for audio needs.

[@abletontechniker2311]

is this background knowledge mentioned in your book about these absorbers?

[@AcousticFields]

A, What book are you referring to?

[@AcousticFields]

A, The link you sent me is to our build plans. We can sell you our carbon technology to go inside the BDA build unit.

[@abletontechniker2311]

Do i get it right? Do you mean 2 different offers? Or do you mean the DIY Plan ? Sorry, my englisch is not that perfect. I really like the idea of these Kind of technology.

[@cengeb]

Carbon, so it's an air filter?

[@AcousticFields]

C, No. Over the counter carbons used to filter air and water will not work for sound.

[@therunway8282]

Something not clear to me is: are the two membranes/walls perforated?

[@AcousticFields]

T, No. Diaphragmatic absorption works on sound pressure, not air flow. Our dual wall construction slows the pressure wave down before it enters the cabinet insides. It then meets a lower pressure area inside the cabinet due to our carbon technology. This pressure change produces attenuation. The lower pressure level inside the cabinet is similar in process to friction with middle and high frequency absorption technologies. Friction produces heat and thus an energy change which produces absorption. We use lower pressure instead of friction.

[@okcyurwin]

Never use the wording "vacuum" when explaining what's going inside your products. Sound / pressure does not not enter a "vacuum" and move to anywhere. Better to say "a near air tight environment" which is nothing like a "vacuum" 🤔👍🏼

[@AcousticFields]

It is a "vacuum" in a sense of the word. In a vacuum, there is no air. Inside our carbon absorption technology, there is less atmospheric pressure inside the cabinet than outside where the pressure waves was created. This pressure reduction is critical in our diaphragmatic absorption process.

[@okcyurwin]

@@AcousticFields hello, surly the sense of the word Vacuum is: a space entirely devoid of matter. The hallway beyond the door of a listening room will have lower air pressure but you do not enter a vacuum when opening the door. The word Vacuum has a meaning which is completely different to the atmospheric properties of your carbon abortion technology and inside the box itself. The word Vacuum is misleading and inappropriate in this context. Love all your video and your passion for high-definition audio representation in smaller rooms 👍🏼👍🏼

[@stevo728822]

Surely if the diaphragm is moving it is merely passing the sound wave from one side of the diaphragm to the other? That's how the skin of a drum creates a low frequency sound.

[@AcousticFields]

+stevo728822 The diaphragmatic movement of the front face construction is designed to slow the pressure wave down.

[@stevo728822]

+Acoustic Fields Sound waves travel faster through solid materials than air so it would naturally speed up (increasing the wavelength). To slow it down would require a gas filled membrane (helium or neon).

[@xNighx]

The membrane will not let 100% energy pass through. Each membrane will reduce the energy passing through. You could, in theory, soundproof a room with nothing but bass drum diaphragms if you used enough.

[@yvindholgernes8950]

@@stevo728822 I'm 3 year late in backup you up. But i believe your are right. The theory behind diapragmatic absorbers is to speed the sound wave up, in order for the damping material to work more efficiently in turning the energy into heat.

[@Oneness100]

@@xNighx I don't think so. The thickest Bass Drum heads are 14mil thick. Two plies of 7 mil mylar for the thickest drum heads, some are only 1 ply of 7mil thick mylar... not really enough mass to do anything to reduce low frequency energy. If anything, they will produce low frequency energy. :-)

[@PeterJonesonline]

We think? What, you haven’t actually tested your claims? Acoustics is a science not an opinion.

[@AcousticFields]

You can read our independent test results on our web site. It would be best spending your time doing that rather than wasting my time with your nonsense.

[@KC-bi9jw]

hahahaha burned! 🤣🤣🤣🤣

[@cengeb]

Build the WALL?

[@AcousticFields]

C, I do not understand your question.

[@derekhart6755]

He’s asking about covfefe