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polyfill, yes or no?

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=1385
Printed Date: August 01, 2025 at 9:52 PM


Topic: polyfill, yes or no?

Posted By: JonnyM
Subject: polyfill, yes or no?
Date Posted: June 18, 2002 at 10:26 PM

Greetings all,

I have two 8" woofers, don't really think they qualify as subs, mounted in seperate sealed enclosures~.45 cu ft each.  The 8's sound "good", but I'd like a little harder, crisper bass, do you think polyfill would help.  The speakers are new and I'm more interested in sq than spl.  I'm trying to get better results w/o replacing the speakers, your suggestions/opinions are appreciated.  Thankx

-JM-




Replies:

Posted By: bberman1
Date Posted: June 18, 2002 at 11:01 PM
Damping the box will do two things. First it will reduce the peaks and dips in the frequency’s. And 2nd  it will give a smaller sealed box the properties of a larger enclosure, which will give you deeper bass




Posted By: Velocity Motors
Date Posted: June 19, 2002 at 6:33 AM

Try filling it with pink insulation that you get from Home Depot or your local hardware store.



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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA




Posted By: paul_barnes
Date Posted: June 19, 2002 at 7:25 AM

if they are brand spanking new then don't forget that the surrounds will be a little bit stiff to start with, give them a chance to "run in" for a while so that the surrounds are nice and flexible.

Adding some damping to the inside of the box does work very well, use something like mastic or similar on the internal joins of the box and if you want to go that little bit further then you can try spreading the pink insulation stuff Jeff mentioned all over the interior of the box, alternatively you can use dynamat original for the actual surface of the internals, not quite sure how that works, but it does make a heck of a difference........

Paul

Just a learned amateur :-)





Posted By: Static Revenger
Date Posted: June 20, 2002 at 10:26 PM

Poly fill,that cheap poly pillow stuffing,acoustic foam or egg crate foam,the pink insulation as mentioned by Jeff,Dynamat as mentioned by Paul,that spray in type bed liner stuff,or even that expanding foam stuff in a can,(also good for sealing a box as well),works wonders for dampening of a speaker enclosure.

Hope this helps you out or gives you some ideas Jonny. posted_image



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Posted By: GlassWolf
Date Posted: June 24, 2002 at 11:54 PM
make sure your boxes are designed well. don't make them "square."
you need to have the side opposite the speakers at a non-parallel angle to the side holding the drivers. otherwise the waves will reflect inside the enclosure and you'll get wave-cencellation.
next, go to K-Mart, and get a bag or two of pillow-stuffing (polyfill) the loose kind not the rolls. open it up and pull it out so its all fluffy and loose. Now fill each enclosure half-way with it.
see how the boxes sound now.
Also for an 8", I'd recommend about a 1 cu ft box per sub. Also try using isobarik or bandpass designs for a different effect.


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-GlassWolf
Pioneer Stage-4, Orion, DynAudio, Fi





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