Pollyfill advice.

[got-one-eight 10+ year member]

I have 4 8" ID's in a box giving them .365 per chamber. This is a hair over their "normal" value but It needs a bit more low end. They say these subs work in a box up to .45 cubic foot. What pollyfill should I use and how much should I use per sub and is there a certain density, type or brand I should use? I just want to give it a bit more on the low end side. Thx for any advice.

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[got-one-eight 10+ year member]

Anyone?

 

[ciaonzo 5,000+ posts]

Add about 8oz. to that volume and you'll be set. You can buy it at any craft store, usually in 16oz. bags. Don't compress it, you want it to vibrate back and forth. Just tease it out and leave it fluffy. Don't let it get pulled into the driver's moving parts, obviously.

 

[Wingman0121 10+ year member]

Add about 8oz. to that volume and you'll be set. You can buy it at any craft store, usually in 16oz. bags. Don't compress it, you want it to vibrate back and forth. Just tease it out and leave it fluffy. Don't let it get pulled into the driver's moving parts, obviously.

I thought the rule of thumb is 1 pound of polyfill per square foot to give 10~15% more enclosure volume?

Go buy some cheap pillows from Walmart, the stuff inside is basically polyfill.

 

[ciaonzo 5,000+ posts]

It's a pound per cubic foot. He's working with just over a third of a cubic foot per driver. 8oz. is a good starting point.

*EDIT* Sorry, I didn't read close enough and advised for a pair. You're running four drivers so just divide a pound of polyfill into quarters and stuff that in each chamber. Should be fine. Sorry.

 

[LiveAudio911 10+ year member]

I hate poly fill why not just build a box for the size you need unless your really that confined.. ?

 

[got-one-eight 10+ year member]

I hate poly fill why not just build a box for the size you need unless your really that confined.. ?

Box is already built to factory spec but they do give a range thats larger then what I built. I want it to be a bit deeper. Not looking for a huge change just something small. Box is built and I am not about to build it again. No huge loss if the poly doesnt help but I used polyfill in a small sealed box with an eclipse 10 that sounded amazing. Its so cheap to try.. why not.

 

[got-one-eight 10+ year member]

8oz is a lot! I measured 6oz which I believe is much closer to the ratio of 1lb per cubic ft. Even this is a good amount but my amount is right per my scale. Will see how this works!

 

[ciaonzo 5,000+ posts]

Yeah, sorry. I probably just confused you because my reading skills were lacking this afternoon.

You're doing it right, about 4 to 6 oz. will be fine for each chamber. Give it a listen and let us know your subjective opinion.

 

[got-one-eight 10+ year member]

Holy crap that made a difference. I swear its louder overall. Could be the subs are better at producing the bass for the song I was jamming before and after but its louder for sure with the polyfill and smoother if that makes sense. I still need more time to listen. I hope I didn't lose to much of the impact these little 8's had. I really loved the kick they produced for rock music.

 

[Wingman0121 10+ year member]

Well if you open up any decent home speakers you'll find polyfill or some sort of acoustic dampening material inside, usually stapled to all the interior walls.

Not only does it increase the apparent enclosure volume but it also eliminates standing waves, so it does help to make the bass smoother, deeper and a bit louder. Polyfill is only useless when you're going for pure SPL.

 

[got-one-eight 10+ year member]

So I think 6oz is a hair much. I lost a bit of the pop I had before although the low end has really picked up I miss some of the thump I had with rock. I think dropping it down to 4oz will be in the sweet spot. 6oz easily exapanded to take up the whole inside of the enclosure. The sub actually packed it off to the back and sides as I installed it. I have to say I am impessed with how much of a difference pollyfil makes. My 4 8" ID's sealed are murdering what my IDmax 10 ported could do. Plus my IDmax had zero kick for rock. Much happier with this setup.

Pics of setup.

http://www.caraudio.com/forum/subwoofers/476395-4-8-id-subs-regular-cab-dodge-ram.html