Polyfill! does it realy work?

[Xprime4 10+ year member]

nice' i'll post result once that expensive operation is finished //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[MAY03TBLT 10+ year member]

Anymore comment on your experience with polyfill? Will it really be audible?

adding fill to mine improved SQ, it didn't meter any higher though

 

[THUMPPER 10+ year member]

The first thing that comes to mind with Polyfill is to add

it to an enclosure and TRICK the woofer into thinking

it is in a larger enclosure...

first of all a Sub Woofer is NON LIVING...it does not think

it is in a larger enclosure when polyfill is added..

I have experimented with Pollyfill in all sorts of enclosures

and these are my findings

Polyfill does 3 things

#1..

Polyfill dampens the echoing sound waves inside the enclosure...

a thin layer on the walls of an enclosure will reduce the amount

of soundwaves rebounding off of the inner enclosure walls and

it also reduces the amount of soundwaves rebounding off of the

back of the woofer cone...

in a perfectly square enclosure it will

reduce the amount of standing waves...

used correctly it will deaden the sound between the notes

creating a smoother sound from the front of the cone

#2...

Polyfill eats up inner volume...if your enclosure is too small and

you add a pound of pollyfill you will reduce the inner cf3 of the

enclosure and the output and low end extension will decrease

doing the exact opositte of the desired effect

#3...

Polyfill traps heat...it works like insullation

in high power systems adding polyfill will

increase the inner temperature of the enclosure..

this is not good for those who like to pound their subs

hard for long periods of time

I have read articles by Richard Clark in Autosound Magazine

regarding on pollyfill and his comments were there was little

or no audiable difference by using pollyfill in an enclosure

this subject is highly controversial and is surrounded by

many different opinions

these opinions are my own...done with several different types

of enclosures and woofers....

there is no substitution for a properly made enclosure....

 

[THUMPPER 10+ year member]

here is an article by Richard Clark (from Autosound Magazine)

Richard Clark11-14-2002, 12:07 PM

guys--------stuffing the box with polyfill has the effect of converting SOME OF THE PRESSURE CHANGES INTO HEAT-----adiabatic means the the system would be loseless regarding applied energy and really does not relate to pressure specifically-------with any spring (except a textbook perfect one that does not exist in nature) there is at least some isothermal effect------the air in the box is a reactance (spring) and when energy is applied (the spring is squeezed)------ the spring returns the stored energy when released------since there are no perfect springs all the energy is not returned-----the energy is lost as heat when the material in the spring flexes------this is no different with an air spring in a woofer box or a car suspension spring------the polyfill makes the box a more lossy system by absorbing SOME OF THE ENERGY by converting it to heat-----that leaves less spring pressure to push on the speaker cone------but the system by no means becomes totally isothermal (meaning all the energy would be converted to heat)-------if it were the box would behave like it was an infinitely large resistance and would resemble a transmission line-----------bottom line?????-------like i have posted about a jillion times-------the effect is subtle at best and does not make a very large (if any) audible difference..........RC

[ November 14, 2002, 12:09 PM: Message edited by: Richard Clark ]

 

[rollerdj 10+ year member]

did anyone read that this is a ported box? last time i checked adding poly won't do squat in a ported box. just sealed.

 

[Xprime4 10+ year member]

did anyone read that this is a ported box? last time i checked adding poly won't do squat in a ported box. just sealed.

i don't see a lot of people using it in ported box, neither in big box (4.2 net is higher than recommended for type r)

that's why I asked the question

So overall, little better sq, but low end boost questionnable?

 

[Xprime4 10+ year member]

Eat internal volume? No good //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

I guess it only happen when there is too much polyfil.. since it's first known use is to "expand" the inner volume

Any more experiences? Comments?

Isn't supposed to help with the heat dissipation? The same way deadener absorb vibration

 

[snoopdan 5,000+ posts]

Polyfill use in a ventend enclosure is to reduce standing waves, and it DOES change tuning - typically increases it, so I dont think this is something that the OP should be doing.

 

[Xprime4 10+ year member]

I was thinking, wouldn't heat dissipate by the port?

 

[Xprime4 10+ year member]

So my best bet would be to only put some and glue it to the back panel of the box so it would absord the standing wave, right? OP?

 

[GlocksRock 10+ year member]

Poly fil is cheap, just try it and if you like it great, if not, then you didn't waste much money. You are the only one that can determine if you like the results or not.

 

[k_schutte 10+ year member]

Serisouly.. buy it, try it and if you don't like it... make a ****in pillow or something.

 

[Xprime4 10+ year member]

or a teddy bear //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

I'll do it then post result tommorow

 

[snoopdan 5,000+ posts]

I was thinking, wouldn't heat dissipate by the port?

nah, the port is serving as a cooling methodology in the first place, having polyfill in there wouldnt have a thermal purpose at all.

 

[Patthebakker 10+ year member]

yeah....... some choices for a purchase\

http://www.google.com/products?q=polyfill&ie=UTF-8&oe=utf-8&rls=org.mozilla:en-USfficial&client=firefox-a&um=1&sa=N&tab=wf