Polyfil? Or Not to Polyfil? That is the Q

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=37582
Printed Date: May 09, 2024 at 8:23 PM

Topic: Polyfil? Or Not to Polyfil? That is the Q

Posted By: MBZ oe
Subject: Polyfil? Or Not to Polyfil? That is the Q
Date Posted: August 17, 2004 at 12:14 PM

I will be installing my new subs today and usually I just put a little polyfil in every enclosure. But does it really make much difference? I built my new Sealed enclosure Exactly to spec for subs, so if I add polyfil the I will be reducing the internal volume. Couldn't this be a negative? Or should I just glue a little in there like I usually do?

-------------
BOOM, BOOM, BOOM BOOM....

Replies:

Posted By: DYohn
Date Posted: August 17, 2004 at 1:35 PM

You will not reduce internal volume, you increase it by adding polyfill. If your enclosure is "built to specs" then you probably do not need it - assuming we are talking about a subwoofer enclosure, that is. No need to worry about standing waves in a sub enclosure, reduction of which is the other function of polyfill (in a full-range system.)

-------------
Support the12volt.com

Posted By: zane9000
Date Posted: August 17, 2004 at 1:47 PM

at the risk for sounding really dumb (which i do quite often so i guess its ok) whats polyfil and how is putting anything into an eclusure going to increase the total volume?

-------------
I had Cheetos and wine for dinenr.

Posted By: promodeepcycle
Date Posted: August 17, 2004 at 2:58 PM

polyfill whats in your cheap ass wal-mart pillows.... and basically your tricking the sub into thinking its in a bigger box ................................. basically...

-------------
dont be a pet monkey ..use your dmm

Posted By: DYohn
Date Posted: August 17, 2004 at 3:52 PM

Not tricking anything, actually. It's physics. By adding lots of area and random channels that the air must pass through, it slows down and flows in many directions instead of all in the same direction. By slowing down the air movement inside the enclosure, it acts as if it was larger than it is (or rather, the air moves like it would in a larger enclosure with no fill.) Using approximately 1lb of good quality polyfill (like the product called "Acoustastuff") per cuft can make the enclosure behave as if it was as much as 40% larger than it is. Standard Dacron polyester pillow filling is not quite as efficient as Acoustastuff and similar products. With standard pillow batting, you can achieve about a 25% to 30% effective increase.

-------------
Support the12volt.com

Posted By: Jay T
Date Posted: August 17, 2004 at 8:51 PM

So thats what that stuff is that makes my box / sub sound so good.

I thought maybe it was for the little bass troll that lives in there to take a nap. LOL

Posted By: auex
Date Posted: August 17, 2004 at 9:05 PM

promodeepcycle wrote:

polyfill whats in your cheap ass wal-mart pillows.... and basically your tricking the sub into thinking its in a bigger box ................................. basically...

How do you know I have walmart cheap ass pillows?

-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Posted By: /R7
Date Posted: August 17, 2004 at 10:12 PM

i guess in ideal 'situation', polyfill could be very helpful for small enclosures needing more area inside the box for air to be filled. rather then padding a spec'd box and creating more space than is needed.

Posted By: dalmyd1
Date Posted: August 17, 2004 at 11:18 PM

I actually tried stuffing my box before an SPL contest just for the hell of it...........BIG MISTAKE!!!!!

Was really funny though.....