Insulation inside a cabinet....

[jbybj]

While waiting to find an appropriate cabinet for my EVM-15L speaker, I have put it in an old Carvin combo, sans amp.

It is very small, maybe half the size of my other single 15 cabs. Sure enough, side by side with my other EVM-15L, it has much less bottom, and more mids. Still sounds decent, just different.

My question: is there a predictable result from removing the 2" thick insulation that lines the interior of the combo? How might that change the tone of the cabinet?

Thanks,

JBY

[Lo-E]

The fiberglass is damping. Since that cab was built for a different driver, it's hard to predict the results, but it'll probably be a little boomier and push the low mids a bit.

Damping usually provides a "tighter", more controlled low end.

[Eric Moesle]

Removing the padding ALMOST ALWAYS makes a bass cabinet sound worse.

I say "almost" as I'm sure somewhere out in the world one person might have had a fluke experience.

I recently played through a ported cabinet that had a 300hz "honk" going on that for the life of me I couldn't adequately dial out. When I opened up the cab to take a peek, only the back wall was padded - the sides were bare wood. I put in eggshell mattress pad foam on all the interior surfaces, and the 300hz "honk" was all but gone.

That's with PORTED cabs. With SEALED cabs interior padding makes the speaker think it is in a larger cabinet and therefore reacts with more low end.

[jbybj]

I'll just leave it be. Less work, better results, I like that.

[billfitzmaurice]

Originally Posted by jbybj

is there a predictable result from removing the 2" thick insulation that lines the interior of the combo?

It will make it worse. Don't remove it.

With SEALED cabs interior padding makes the speaker think it is in a larger cabinet and therefore reacts with more low end.

Myth. It lowers the box Q, which helps to tame the boom that results from a cab that's too small. A larger cab lowers Q, and a larger cab also lowers the box frequency, which increases low end sensitivity, while stuffing does not.

[Eric Moesle]

Thanks Bill. I always learn something new from your posts.

[billfitzmaurice]

Originally Posted by Eric Moesle

Thanks Bill. I always learn something new from your posts.

The myth of box stuffing is understandable, some very well known industry names accepted it as gospel until recently. The difference between a smaller stuffed cab and a larger lined only cab is subtle, and without taking precise measurements it's easy for the one to appear like the other, especially if the two boxes are within 10% or so of each other in size. But some sources claimed you could reduce a box size by up to 25% and that stuffing it would compensate fully for so doing, and that was way off the mark.