My buddy got his system installed from best buy.

We were changing his sony crapy explodes out for some good ol JL w3s

When I took the sony out I noticed his Sealed boxes had insulation almost like cotton looking material.

Any body ever herd or know about this.

I would imagine it "POSSIBLY" make the sub slightly quitter and warmer sounding for a better sound quality, but idk just left it in there.

 

I may be off base as its been awhile since I messed with car audio, but if I recall adding insulation basically makes the box act larger then it is. Every sub has a specific air volume that it performs best with, I think if size is a restraint then insulation is used to help.

I think....

 

It's called Polyfill. It makes the speaker think it's in a bigger box, and it works well.

 

Well in that case!!!

I have 2 10" JL w3v3 each in a .85 cubic ft under rear extcab seat
1 box with divider .85 each sub JL specifications .625 cubic feet.

so would putting this polyfill be negative to make my subs think it is a larger box since my box is alreay .225 cubic feet larger

I'm wanting my system to be extremely clean/blending with all music. I don't care about loudness it's already to loud for me when I crank it. The JL subs and door speakers are extremely clean but not as clean as I would like.

I am running alpine V1000 to subs and alpine V400/4 to my door speakers
Would JL amps bring a noticeable difference in sound quality?

Older Alpine head unit as well.

 

Every time I stuffed a box, they sounded better and got louder.

 

I always found filling the speaker box created a better sound IMO.

 

Pillow cotton works good as well and much cheaper

 

Yes, I have used that before.

 

What is to much polyfill/pillow cotton in .85 cubic ft space?

 

LOL, you said '' I stuffed a box"


To the OP yes that is common, esp in small enclosers