Balls!

[ashtray]

I just learned that cell phone speakers use foam balls inside the sealed enclosure to absorb sound and energy from the rear sound wave that a speaker produces - much in the same way that adding foam inside a bass cabinet does. That did get me thinking: has anyone tried using foam balls inside a sealed bass cabinet, instead of foam lining?

 

[Hoochie Coochie Man]

I expect that foam balls would not offer any benefit compared to the traditional way damping materials are used and may be likely to cost more as well.

But, what do I know? I suggest that you try it and let us know what the results are.

 

[agedhorse]

Keeping them tethered would be a challenge, especially "big balls"...

Actually, years ago I worked with a tour manager named Jimmy Big Balls, he was Lisa Lampanelli's tour manager and later her husband. Yelling "hey Mr. Big Balls" always got a bunch of the crew's heads to turn!

 

[monsterthompson]

Cue Bon Scott…

 

[onda'bass]

From the left and to the right

 

[LSM07]

what about foam carrots?

 

[PeaveyPlayer]

Also done in car audio!
I've been dipping into RTA tuning and such using home application woofers and a 1 inch tweeter with sub in a 2 way active situation with DSP

I've used Closed cell foam behind the midbass to help with the rear wave and deadening

 

[Jaygetsreal]

Actually yes but not for that specific purpose. I have a custom 50w combo which has an eminence 10" whizzy cone speaker (B102) which was not performing. I redid the TS calculation and found the volume was a bit big for that driver and reflex port. So I put about 6 polystyrene balls in, carefully calculated in volume, wedged tight so they don't buzz, and in that way reduced the cabinet volume. I assumed of course that they are effectively incompressible. I can now drive it a bit harder than before.

 

[Hoochie Coochie Man]

Actually yes.but not for that specific purpose. I have a custom 50w combo which has an eminence 10" whizzy cone speaker (B102) which was not performing. I redid the TS calculation and found the volume was a bit big for that driver and reflex port. So I put about 6 polystyrene balls in, carefully calculated in volume, wedged tight so they don't buzz, and in that way reduced the cabinet volume. I assumed of course that they are effectively incompressible. I can now drive it a bit harder than before.

I understand the concepts involved at a very basic level. Either you know what you are doing, and you are a genius, or you are a crackpot.

 

[Jaygetsreal]

The latter.
As evidence: https://www.talkbass.com/threads/eub-design-and-build-and-some-lessons-learned.1314694/

 

[FretRiff]

I just learned that cell phone speakers use foam balls inside the sealed enclosure to absorb sound and energy from the rear sound wave that a speaker produces

Which cellphones did you hear do this? I've seen several opened smartphones, from Apple and Samsung, and they use acoustic mesh or foam pads/sheets, not balls.

 

[ashtray]

Which cellphones did you hear do this? I've seen several opened smartphones, from Apple and Samsung, and they use acoustic mesh or foam pads/sheets, not balls.

Teardown of the iPhone 17 Pro. I'll find the video…

 

[Fender_Bender]

Keeping them tethered would be a challenge, especially "big balls"...

Actually, years ago I worked with a tour manager named Jimmy Big Balls, he was Lisa Lampanelli's tour manager and later her husband. Yelling "hey Mr. Big Balls" always got a bunch of the crew's heads to turn!

Reminds me of the William Shatner roast where he said "I'm going to go where no man has gone before, home, to J-off to Lisa Lampinelli" .

 

[Michedelic]

 

[6thplanet]

Also done in car audio!
I've been dipping into RTA tuning and such using home application woofers and a 1 inch tweeter with sub in a 2 way active situation with DSP

I've used Closed cell foam behind the midbass to help with the rear wave and deadening

If you're using it inside the door behind the midbasses, be cautious to know doors aren't sealed. Water can get in pretty easily in some doors and most have drain holes at the bottom. Issue is foam will absorb the water rendering it useless and now holds the water in the doors which can lead to rust/corrosion.

 

[PeaveyPlayer]

If you're using it inside the door behind the midbasses, be cautious to know doors aren't sealed. Water can get in pretty easily in some doors and most have drain holes at the bottom. Issue is

foam will absorb the water rendering it useless and now holds the water in the doors which can lead to rust/corrosion.

They Say CCF is water proof apparently

Some guys even remove the Vapor barrier when they do it

The CCF goes usually over top the the sound deadner

deadner/ Ccf/mlv

 

[agedhorse]

If you're using it inside the door behind the midbasses, be cautious to know doors aren't sealed. Water can get in pretty easily in some doors and most have drain holes at the bottom. Issue is foam will absorb the water rendering it useless and now holds the water in the doors which can lead to rust/corrosion.

I agree.

 

[6thplanet]

They Say CCF is water proof apparently

Some guys even remove the Vapor barrier when they do it

The CCF goes usually over top the the sound deadner

deadner/ Ccf/mlv

Ok, I thought you miss typed "close cell foam" as this doesn't do anything for the rear wave. What your talking about is just vibration damping/control.

Which is fine for it's intended purpose and waterproof.

 

[agedhorse]

CCF still retains water around the cut edges (where it's no longer closed)