amp mounting location

Is it bad to mount an amp to the sub box? I really don't have a great place in the trunk of my car other than the sub box to mount my amps.

not at all if the box is sturdy and doesn't vibrate or flex

A subwoofer enclosure that doesn't flex or vibrate.    Hmmmm.

When I have to mount an amp to the enclosure, I put foam behind the amp to give it a cushion and then I dont tighten the screws down tight.

Personally, I refuse to put extra holes in any enclosure ever. You want the tightest seal possible and screw holes compromise that.'94 Ford Explorer / Kenwood KVT-815DVD / RF Power T1682C 6x8 (all doors) / RF Power T10001 / 12" Kicker L5 (x4) / Optima Yellow Top Battery

Use short screws so they don't go completely through the box wall. You should also make sure that the box can't slide around the trunk. This will prevent any undue stress on the wires connected to the amp. Make sure the amp isn't smothered against a rear seat to allow it to stay cool.sparky

I agree with sparkie. On my fiance's amp I had to mount the amp to the back of her box so that she would have as much trunk space as possible. I simply put some foam under the amp then mounted it to the box using 3/4" screws. I did not tighten the screws all the way down that way the foam can do its part to dampen the amp from vibrating. Basically the screws are there just to keep the amp in place, but not tight against the box. Its worked perfectly.