makin box bigger

[Lets Get It 10+ year member]

i got a 3.5 tuned to 38 box lookin to get it to around 4-4.5 cubes tuned to 38-40. Tryin to see how much polyfill do i need to add to get it to that? i know itll raise the tuning, but dont know by how much.

and how do i secure it to the box?

Click to read more...

 

[Immacomputer 10+ year member]

Polyfil doesn't change the box size but rather the alignment. In a ported enclosure, adding polyfil will really just make it quieter and reduce output around tuning.

 

[ultimate157 5,000+ posts]

Polyfil doesn't change the box size but rather the alignment. In a ported enclosure, adding polyfil will really just make it quieter and reduce output around tuning.

Erm... ?

Why do all the small ported HT enclosures I've opened up have polyfill in them?

 

[Immacomputer 10+ year member]

To lower the alignment and to reduce output around tuning! It also helps dampen the rear wave so if the driver is playing midrange frequencies as well, the standing waves are also damped.

 

[Lets Get It 10+ year member]

so polyfill doesnt make the box bigger?

 

[bones22 5,000+ posts]

so polyfill doesnt make the box bigger?

new wood will

even if the polyfill would help you thats a huge jump in size

 

[Lets Get It 10+ year member]

new wood willeven if the polyfill would help you thats a huge jump in size

yea i know, but im tryin some other options b4 i built another box

 

[Immacomputer 10+ year member]

so polyfill doesnt make the box bigger?

No. It changes the alignment (most of the time it lowers it but sometimes it increases it) which is basically the damping of the system. People get it confused with box size because box size also directly changes the alignment. But in an enclosure, that is not the only thing that changes when the size in increased.

It's easy to see how people get confused on the matter and if you want to see for yourself, try adding polyfil and see how the sound changes. Then if/when you build a new box, see how that compares to the polyfil setup. I think you will see that I am right in saying that each alter the alignment but besides that one aspect, they're very different in their effects on the system.

 

[mlstrass 5,000+ posts]

You could shorten the port to raise tuning and gain a little volume, but you really need to just build another one to gain that much size.

What sub are you running?

 

[Lets Get It 10+ year member]

You could shorten the port to raise tuning and gain a little volume, but you really need to just build another one to gain that much size.
What sub are you running?

15 hdc3