ported box lining (1 Viewer)

[steve_gal]

Hi.has anyone any suggestions on a cost effective material to line the inside walls of my ported sub?.
Do i have to line all the sides? why is this done,is it just to stop reflections of the sound waves?
Just a thought,i have some wavy rubber underlay that we use under carpet in the UK(i don't know if it is used in the USA)lying around could i use this?.

 

[ThomasW]

Use either bonded polyester batting or acoustical foam (open cell). Cover the largest internal surfaces.

It absorbs the higher frequencies that aren't filtered out by the crossover. It also makes the box look slightly larger to the driver.

Underlayment will work IF it has an open cell structure (foam). If the surface is sealed it won't be helpful

 

[Shawn Keeler]

Thomas nailed it. I am not sure how much shipping to the UK would be, but this were I get all my foam from;

http://www.stores.ebay.com/store=56630986

Hope this helps.
Shawn

 

[steve_gal]

Thanks to both of you.Thomas how do i distinguish between open and closed cell foam?

 

[ThomasW]

You look at it.

Open cell looks like a sponge, the cell walls are open to the air.

Closed cell foam has a sealed outer surface.

 

[steve_gal]

didn't think it was as complicated as that.