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geekhack Projects => Making Stuff Together! => Topic started by: Leopard223 on Sun, 23 May 2021, 19:45:38

Title: Should I add acoutstic cutouts to a plate I'm making?
Post by: Leopard223 on Sun, 23 May 2021, 19:45:38
I had them on my sketch and realized they're just where I planned to put holes for a 3D printed "PCB"'s standoffs, plus they probably add to the price.
Do they actually have any impact on sound? I'm planning to make the plate out of Carbon Fiber.

For anyone not familiar I'm referring to those  (https://imgur.com/a/bRui58B)cutouts.
Title: Re: Should I add acoutstic cutouts to a plate I'm making?
Post by: jamster on Sun, 23 May 2021, 20:46:41
Are acoustic cutouts common on these plates?

I've never seen one, my only acoustic experience is building speakers, but I find the idea of those cutouts in a plate riddled with other holes, especially in a material as damped as CF, kind of laughable.

Edit: From an acoustics perspective, those cutouts are either supposed to let sound through (which makes no sense considering there are lots of other holes, lots of caps in the way) or change the resonance of the plate (which makes no sense to me because CF, I doubt it makes any difference with other materials too). I'd be interested to know if whoever designs plates like this ever does frequency testing.
Title: Re: Should I add acoutstic cutouts to a plate I'm making?
Post by: Leopard223 on Sun, 23 May 2021, 21:24:13
Are acoustic cutouts common on these plates?

I've never seen one, my only acoustic experience is building speakers, but I find the idea of those cutouts in a plate riddled with other holes, especially in a material as damped as CF, kind of laughable.

Edit: From an acoustics perspective, those cutouts are either supposed to let sound through (which makes no sense considering there are lots of other holes, lots of caps in the way) or change the resonance of the plate (which makes no sense to me because CF, I doubt it makes any difference with other materials too). I'd be interested to know if whoever designs plates like this ever does frequency testing.
I was designing a plate so I thought why not? but there's really no info on acoustic cutouts, seems like a gimmick, sadly keyboard science is very minimal especially this days. 
From research it doesn't seem like KeyCult or Rama does any of those cutouts so maybe it is a gimmick? I don't know if those brands are supposed to be keyboard experts but I'd imagine if it has any benefit you'd see those on the high end keyboards.
Title: Re: Should I add acoutstic cutouts to a plate I'm making?
Post by: jamster on Sun, 23 May 2021, 21:44:09
If you're making the plates, then just make one with, and one without, then compare them.

I personally have doubts they'd do anything. The 'acoustics' part there would be resonance and having a couple of tiny slots cut out in a 25cm length of CF that's got a whole load of other stuff embedded into it seems highly unlikely.

Title: Re: Should I add acoutstic cutouts to a plate I'm making?
Post by: Leslieann on Sun, 23 May 2021, 21:49:33
Sound is difficult.

I highly doubt they have the ability to do enough to matter and I'd be more concerned with what it will do to that sound if it does.
Title: Re: Should I add acoutstic cutouts to a plate I'm making?
Post by: MIGHTY CHICKEN on Sun, 23 May 2021, 22:48:25
Feel like the usual thing it does is just add flex to areas of the plate cause "gasket bounce go brrr"
Title: Re: Should I add acoutstic cutouts to a plate I'm making?
Post by: Ranger_Trivette on Mon, 24 May 2021, 05:01:34
acoustic is a really complicated science.
i've studied exhaust systems for work.
is hard to predict the sound waves in a pipe, imagine the reflection of sound waves inside a keyboard. :-X

my advice is to understand what your goal is and try to move is this direction.
if you want to reduce noise add foam, use material that absorb sound waves etc.
realise a first sample. then try different solutions on it.


i can't imagine how these cutout may effect sound.
they probably won't.
but you have to try it to be sure.
Title: Re: Should I add acoutstic cutouts to a plate I'm making?
Post by: Leopard223 on Tue, 25 May 2021, 09:47:46
acoustic is a really complicated science.
i've studied exhaust systems for work.
is hard to predict the sound waves in a pipe, imagine the reflection of sound waves inside a keyboard. :-X

my advice is to understand what your goal is and try to move is this direction.
if you want to reduce noise add foam, use material that absorb sound waves etc.
realise a first sample. then try different solutions on it.


i can't imagine how these cutout may effect sound.
they probably won't.
but you have to try it to be sure.
Thank you for the detailed answer! Guess Iíll have to experiment to find out.