Increasing bass response in a 4x12 cab

[burning]

short question: how do i increase the bass response of my speaker cabinet?

My cabinet is a 4x12 homemade cabinet built out of 15mm plywood (i think it's 15mm) over a skeleton made of 2x4s. It's currently covered in carpet on the outside. and the inside is bare but all the edges are covered in silicone sealant.

The speakers are celestion vintage 30's, which means they scream with the treble - but my bass response is lacking the desired balls. Also when my amp is cranked to high levels my box resonates on some notes, making a honking sort of noise.

After searching around the forums for a while i've heard that i can increase the bass response of my cabinet by adding some sort of sound insulating material to the inside of my cabinet. This should also help with the resonance issues I think.

Should I be using eggcup shaped foam (which i have a bit of lying around, or carpet (which i can buy), fibreglass, or something like dynamat?

Or is there a better way to increase the bass response?

[karahara]

Hi.

Has it a closed or open baffle?

[fdeck]

Bass or guitar?