if the inside was lined with foams would it work better?
I want to have a box that i can setup a mic in relation to a speaker, find the sweet spot, and not have to re-setup everything every time i want to record, it would always be ready, and in addition, would be isolated.
In all likelihood, it would sound like absolute shit.
If I ever got to that point, I would simply go direct and use a Palmer speaker simulator. Wouldn't have to worry about setting up mics ... you'd get near perfect isoloation, and the sound would at least be somewhere between decent and good.
check out http://www.homerecording.com/bbs/showthread.php?t=224357
THat is pretty much the idea i used for my iso box, which i am pretty happy with, but for isolation, you really need to think box-within-a-box in my opinion.
I doubt if a literal cube shape would be the best for recording. If i were to do mine again, i woud definatly want there to be some length to the box, so there is wall-speaker-mic- 2 or more feet of space behind the mic for absorbtion and breathing room. Someone with a real undersatnding of acoustic physics could probabaly be able to verify, dispute or calrify that.
A PSM is not an amp modeler. You run direct out of your amp, and it does a convincing job of mimic'ing the sound of a mic against a speaker ... which is much less difficult than trying to simulate the sound of tubes being driven.