Do you put Sound deadener inside Fiberglass Sub box?

[cobraa]

I have a roll of sound deadener( Fatmat 80mils) and was wondering if I should put 1 layer inside my FG sub box or it wont do anything?

Thanks!

[DIYMA]

[tinctorus]

I wouldnt I would fill it with resin to seal it up and if it is a sealed box possibly stuff it with polyfill, That is if you need the polyfill.

On my box I built for the corner of my srt I had to build it a bit undersized in order to get it to fit how I wanted it to so I stuffed about 3 pounds of polyfill in there to make up for some of the space I needed

It wont "hurt" anything to fill it with deadener but I think you could make better use of it in other places

[glidn]

I started sound deadening my sub boxes around 15 months ago. Now no longer need stuffing in box and also completely seals box, So two methods of making sure box is sealed.

I noticed my 8" sub play alot lower with sound deadened fibreglass box, than fibreglass box with SD. Just make sure SD has no reflective surface, If it does, Run a couple of pads of Dynazorb behind the sub driver.

[danielp]

If you used Resin to seal the box then there is no need to use the deadener.
Rather use it some where else.

I have seen SPL guys using deadener inside their enclosures but i doubt it makes that much of a difference. If the box is sealed with resin, how much more do you want to seal it?

[glidn]

Originally Posted by danielp

If you used Resin to seal the box then there is no need to use the deadener.
Rather use it some where else.

I have seen SPL guys using deadener inside their enclosures but i doubt it makes that much of a difference. If the box is sealed with resin, how much more do you want to seal it?

It's not so much as sealing the box, as it's killing or absorbing some of the rebound sound waves playing against the box back at the sub.
It's the main reason I do it. Again I have also found it seems to have a cleaner deeper sound. Which is all good.

[danielp]

I understand. Good bracing is Key then..

[GlasSman]

Brace the box properly....if you need to use resin to seal the box you're using the wrong material.

And if you had to seal it up for some reason Titebond II or III would be vastly superior to a brittle, 2 part, toxic resin....on many levels.

[petermakar]

not neccessary. but wouldnt hurt....

[fallbrookchris]

I have never used SD mats in speaker boxes but I have used sound absorbing mats in my HT speakers and subs, I have bought the good stuff from parts express and use carpenters backing (the grey with different color threads in it) as well

I generally seal my FG boxes with FB resin by pouring it in the finished box and moving the box around so it is completely coated, if I "feel" like I need it I then add some SA tiles (egg crate looking stuff) especially in subwoofer boxes, or another type of closed cell foam in boxes with diagonal walls to "catch" the back wave of from the speaker and in other area's in the box as well, I can't really see any benefit to adding SD to the inside of a heavy, well built FG box that has solid strong thick walls, if the box doesn't sound solid when you give it the fist/tap test it isn't strong enough and you have to add a few more layers

[don_chuwish]

Anyone besides Whitledge tried this stuff? http://cascadeaudio.com/car_noise_control/vb_fd.htm

- D

[fourthmeal]

Anybody still use the "milkshake" technique of coating the box's insides? That's what I do. Part kitty-hair or short-stranded goo, part Resin. Mix it up, pour it in, and move the box around so all of it is coated.

[nineball]

Originally Posted by fourthmeal

Anybody still use the "milkshake" technique of coating the box's insides? That's what I do. Part kitty-hair or short-stranded goo, part Resin. Mix it up, pour it in, and move the box around so all of it is coated.

i understand the concept but i always thought it was a waste. for example we will say you are making a corner box. the only part that would possibly need "sealing" on the inside would be the seam, not the entire box, so why waste product? unless you laid the glass wrong (and that is a problem unto itself) there should be no possible chance of air escaping anywhere other than the seam. i like using a small amount of duraglass on the inside seam.

[fourthmeal]

I think it is just to create a more solid layer, and fill in pin-holes.

I suck at FG though. Probably because I lack the patience needed for it.

[nineball]

if you have holes on the inside after laying 5-9 layers of glass on the outside you have bigger worries fg is easy but you do have to take your time.

[RBeachTL]

I used CLD on the inside of my fiberglass enclosure. The enclosure is covered with carpet but still had structural resonance. I would use the rap test and I could definitely hear the structure ring. When I added the CLD the enclosure is now pretty dead.