Polyfil

[Compjake 10+ year member]

ok, quick question.. say I have a 12 in sub that needs a 2 cube slot ported box, what would give the highest SPL?

1 12 in 2 cube box

or

2 12's in 2 cube box using about 2lbs of poly fill?

also assume ether way the sub(s) will be given there rated RMS

I don't plan to do this but Ive heard mixed messages about using polyfil and would like to know some opinions

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[CrazyKenKid 10+ year member]

well put it this way poly fill tricks the sub into thinking it is a bigger box! so i use polyfill to aviod using a huge box! and the sound quality is also a bit nicer!

rule of thumb for every 1cubic box put 1lb of poly fill in!!

o wiat you are putting polyfill in a ported box..i have only done poly in a sealed box lol will the polly fill come out the port lol!

 

[John_E_Janowitz 10+ year member]

Polyfill isn't really too effective. IT has some effect but you want something with better thermal properties for it to work well. It is the thermal properties that give you the apparent increase in box volume. Regular fiberglass insulation is good as is rock wool or mineral wool. In general you don't want to fill a vented enclosure. You can line the sides, but totally filling the enclosure will decrease your lower impedance peak and cause you to lose some output.

John

 

[Compjake 10+ year member]

I figured you would just use a staple gun in 4-5 spots to hold it down so it doesn't some out the port.

ether way, witch setup should be louder?

 

[pr-festiva 10+ year member]

are the two 12's going to be in a ported box too?

 

[CrazyKenKid 10+ year member]

i would say go with 2 ported 12's would be louder! no poly fill! 2 subs are alwasy louder for some reason! lol!

 

[SPL Blazer 10+ year member]

Even if you stapled the polyfil in a couple places it's still going to blow out the port eventually. The only way to keep it in there is to use a mesh netting or wire netting and cover the inside port opening with it. But doing this also blocks for port and greatly reduces the output. In a sealed enclosure it can be used, but it's really pointless in a ported one.

 

[kodak314 10+ year member]

ok, quick question.. say I have a 12 in sub that needs a 2 cube slot ported box, what would give the highest SPL?
1 12 in 2 cube box

or

2 12's in 2 cube box using about 2lbs of poly fill?

also assume ether way the sub(s) will be given there rated RMS

I don't plan to do this but Ive heard mixed messages about using polyfil and would like to know some opinions

1 12

and polyfill doesnt make the subs think the box is bigger

 

[SPL Blazer 10+ year member]

Ahh, yes it does. It "tricks" the sub and the waves into thinking it's in a larger enclosure than it really is. This is pretty much a known car audio fact.

 

[CrazyKenKid 10+ year member]

Ahh, yes it does. It "tricks" the sub and the waves into thinking it's in a larger enclosure than it really is. This is pretty much a known car audio fact.

lol i knew i was right and not crazy! the crazy thing is the sub! silly sub so gullible //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[n2audio 5,000+ posts]

the polyfill dissipates heat inside the box and takes energy from the "air spring" so the box acts larger than it actually is.

http://www.audiojunkies.com/blog/1348/ultimate-polyfill-subwoofer-enclosure-resource

I was all set to build a dual 12" ported enclosure relying on polyfill for about a 40% hike in volume, but decided to stay with a single sub so I'm back to having enough volume w/o it.

I would like to see a case of poly being blown out the port. Doesn't seem logical. It is sucked in just as much as it's pushed out.

 

[Compjake 10+ year member]

Well I know the dynamics of polyfil, what I wanted to know was if 1 12 in a proper sized box would be louder or quieter then 2 12's in a the same box (box would be 1/2 the size it should be) and using poly fill.. I haven't seen an answer to this lol

 

[SPL Blazer 10+ year member]

Your asking a question that can't be answered with a simple yes or no. You need to try each method on your own and see which one you think is louder. Things like this differ between vehicles, enclosure placement, power etc.

 

[pr-festiva 10+ year member]

poly is not going to give you that extra 40%,you will have a beefy set of mid basses how ever trying to stuff two subs where one should be.If you realy want 2 subs mount them iso baric

 

[Slammed 5,000+ posts]

polyfill works for me

//content.invisioncic.com/y282845/emoticons/thumbsupwink.gif.129404938effda6ad9cca39e7f4b58a3.gif