How much polyfil?

[Inu_Yasha]

I was searching the board trying to find the thread with the link that says how much polyfil to use per cu ft. Does anyone know of the link, or know about how much to put in per cu ft?

[PMazz]

Start with 1 lb/ft^3. Adding more will tighten up the bass slightly but adding too much more will kill it some.

Pete

[RandyMidd]

It depends how big your speakers are and how big (or small) you want to have the woofer believe it is.

I asked the same question not long ago...Thomas gave me this link. .

[Amphiprion]

There is no 'right amount'. There are guidelines that will get you close. The only way to get 'the right amount' is to measure the impedance of the sub with various amounts of stuffing and 1) stop when you get to the system Q you desire or 2) stop when you maximize the apparent box volume, whichever you prefer. You can do this with a sine wave generator like NCH tone and a multimeter, or more advanced tools like the PE woofer tester 2 or the most advanced tools like Praxis/Clio/Etc/.

But 1-1.5pcf is a good place to start.

[David G]

I just fill it loosely with polyfill, taking care not to compress it too much.

[Amphiprion]

Another question: How do you keep polyfil from getting into the motor structure/VC gap? With all the venting they use nowadays I'm tempted just to wrap the motor in some old pantyhose.

[ThomasW]

I'm tempted just to wrap the motor in some old pantyhose.

Your personal life aside..... :B

I'd use nylon mesh window screen material.... :T

[Netweaver]

Thanks for this thread and HTGuide. I am building a 15inch TC3000 in a 3 Cubic ft sealed box and want to know how much polyfill needed. I thought of creating a thread and here is the thread already.

Based on the recommendation in the link in this thread, I think a 4.5 pound polyfill from wallmart is good enough.

Please comment.

Thx.

- PK

[ThomasW]

http://www.htguide.com/forum/showpost.php4?p=223825&postcount=1