DSP - how, why, tro...
 
Notifications
Clear all

DSP - how, why, troubleshooting, different hardware, etc.

Page 6 / 6

ajc9988
(@ajc9988)
Estimable Member Registered
Joined: 9 months ago
Posts: 213
Topic starter  

@nixem - yes. So it should be like Dacron, polyester varieties, etc.


ReplyQuote
ajc9988
(@ajc9988)
Estimable Member Registered
Joined: 9 months ago
Posts: 213
Topic starter  

@nixem - That is Dacron/PET/Polyester types material. At 0.0003in displacement compared to 0.016 from the Melanine, and with a way higher starting frequency around 621Hz compared to 116Hz for Melanine, and with that only being half an inch of Dacron, I'd say do dacron/polyester before trying with the foam. It is already decently cheap.


ReplyQuote

Nixem
(@nixem)
Eminent Member Registered
Joined: 3 months ago
Posts: 23
 

@ajc9988 

 

Do you think two 1/8" tempered hardboard panels laminated with a dampening adhesive would be any good, then add bracing/Dacron? Trying to think of ways to increase cabinet volume by reducing thickness but keep resonance/dampening reasonable.


ReplyQuote
ajc9988
(@ajc9988)
Estimable Member Registered
Joined: 9 months ago
Posts: 213
Topic starter  

@nixem - From my tests to date, Insulation > CLD (which is what a dampening layer or adhesive between two panels is) > bracing.

I'm on that same mission, now running simulations on 1/2" (12mm) boards instead of 3/4" (18mm) which is where I first started, that way to reduce weight (and cost).

So, first thing is pick an insulation. Whether that is mineral wool or denim or polyester/dacron, how those perform is well known for acoustic properties. Certain foams help (melamine doesn't seem to be that great). Wool used to be more common, though synthetics are found a lot more in speakers now.

After you pick the insulation, you then can reduce how much bracing you do as the insulation absorbs the pressure from the drivers better than the bracing reduces the displacement, so you already would be far ahead just by using even 1/2" (12mm) dacron for furniture. Then do cross bracing (meaning vertical and horizontal across the plane, I'm currently running models on the effects of braces running to the opposing walls) about 2" toward the center (or less if you have to due to size).

If you have a reason to do the CLD with a viscoelastic adhesive, then do it. It is much better than bracing, but is less than insulation.

You can reduce bracing, though, just on the performance of the insulation alone. So, first decide on the insulation and the thickness of said insulation. Then, move onto bracing. If you have a reason to use CLD, like absorbing tons more energy not captured by the insulation due to frequency or something like that (sub-100Hz), then doing that is fine.


ReplyQuote

ajc9988
(@ajc9988)
Estimable Member Registered
Joined: 9 months ago
Posts: 213
Topic starter  

@nixem - yes. When looking up Dacron, it gave me PET, so I plugged those numbers in. When I next looked up polyester, it pointed to PET being a large variety of polyester now used, so I didn't do a separate polyester run. As such, I group Dacron with PET and Polyester with PET. And it did perform well in the FEA. Further, it looks like what was used with the acclaimed subwoofer from monoprice, the THX one. It has been used for decades in the loudspeaker industry, so is a safe and cheap bet.


ReplyQuote
Nixem
(@nixem)
Eminent Member Registered
Joined: 3 months ago
Posts: 23
 

@elliottdesigns 

Do you have experience with adding an IR remote to the Teensy? Or, how are you controlling it?


ReplyQuote

Nixem
(@nixem)
Eminent Member Registered
Joined: 3 months ago
Posts: 23
 

@ajc9988 

Man, this will be super interesting, keep us updated!!


ReplyQuote
ElliottDesigns
(@elliottdesigns)
Reputable Member Moderator
Joined: 2 years ago
Posts: 254
 

@nixem I'm programming it through usb and then running it off of usb power. It doesn't need to be controlled after that since the profile has been applied and it's just a processor, the main volume will be controlled using the device outputting the audio, the teensy just processes it and passes it through.

Elliott Dyson - Mechanical Engineering Student and 3D printing & Design Freelancer


ReplyQuote

Nixem
(@nixem)
Eminent Member Registered
Joined: 3 months ago
Posts: 23
 

@elliottdesigns @ajc9988

 

Just thought I would share.

 

The first half of this video about audio is interesting.

 

This one is also interesting.

 


ReplyQuote
Page 6 / 6

Newegg

Share:
%d bloggers like this: