[beatbox]

Is it safe to mount a woofer so that the rear of the motor structure is an inch from the backside of a box, or will that hinder the way the woofer cools itself or operates?

 

[Mr. Big Stuff]

Ideally you want a couple of inches, but one inch won't hurt your sub. The real problem would be suffocating the cone by overstuffing the spaces in the basket. Just make sure that if you use any type of insulating matierial (e.g. dacron, reclaimed carpet padding) that you still have some breathing room.