How Essential Is Fiberglass Resin/PolyFill?

I've built a box for my two 10" subs. For two sundown e10d4s. 2.1cubes to be tuned to 35hz by 3" precision port for those who wanted to know. Since I'm using a precision port so I didn't think I needed to use fiberglass resin or another sound dampening material as its not a slot port type enclosure. Then I was reading about enclosures in general on the12volt.com and it spoke very highly of using a type of sound dampener like fiberglass resin because it maximizes output.

Should I get some fiberglass resin or poly fill? Is it that necessary? And I assume PolyFill is cheaper so can I use some adhesive and glue it down to the walls of the box to keep it from exiting the port? How much?

For the fibreglass resin, are you talking about mixing up a batch and just "painting" the inside of your box?

don't worry about doing any kind of fiberglass work on that box....wouldn't notice a difference
as long as it has good joints and plenty of glue it's fine

Edit: you're saying fiberglass resin, are you talking about fiberglass insulation? That's what I thought since you're also mentioning polyfill

It is so essential, I have exactly 0 of it in my box.

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Originally Posted by heebs 09gts

For the fibreglass resin, are you talking about mixing up a batch and just "painting" the inside of your box?

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yes painting it

Quote:

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Originally Posted by bhsdriller

don't worry about doing any kind of fiberglass work on that box....wouldn't notice a difference
as long as it has good joints and plenty of glue it's fine

Edit: you're saying fiberglass resin, are you talking about fiberglass insulation? That's what I thought since you're also mentioning polyfill

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yeah i was very generous with glue and have more if needed. i was talking about the kind you paint on.

resin and fiberglass are used to stiffen an enclosure and make it air-tight. MDF is porous by design, which means it's a bit lossy as-is.

polyfill is not near as effective as fiberglass batt insulation or acoustic insulation/sound batts. but for a vented enclosure - you don't want to block the pathway for the port or you create an aperiodic enclosure.

for my home subs, i pack the ports with an acoustic material to make it more aperiodic - it tames resonance and impedance rise. i wouldn't do it for car subs where high output is desired. i have ran aperiodic in a car when SQ was desired.

none of these provide "damping".

Oh I see. So I'm ok where I'm at then. Thanks

I think he's talking about some people who coat inside of box with resin for extra stiffness. But that's not necessary if you use 3/4" MDF and brace the joints.