To me it is obvious why the amp should not be mounted on the woofer box. Vibration of course...

 

I don't understand that logic at all. A properly built enclosure will have no flex, so the only way it can be vibrated is via the sound waves. So how is it better to mount the amp to say, the backseat, than to the box? Last time I had my system bangin', my back seats looked like they were moving quite a bit. And since most cars with bangin' systems have roof/windshield/door/window/quarter panel/trunk flex, it seems to me that the waves pretty much do work on anything not cemented in or down regardless of what or where it is.

 

I'd say it could POSSIBLY damage the internal components in the amp and it would be easier to steal.

Crack the trunk open, cut the wires on the amp and someone could steal the sub+amp a lot faster than if it was mounted some wheres else.

 

Ease of theft wasn't even on my radar

 

I would not assume a well built box BTW, someone on a budget is on a budget and things aren't always done properly. A poorly built and a properly built enclosure will have flex, period... well maybe not the guys who hit over 160dB their enclosures are pretty rigid. I think this is a question where proper mounting is assumed, but I think vibrations will eventually do their damage, fatigue failures/ stress fractures etc and these take time (years) to develop, so the lower the amplitude of vibration the better. The sub box is ground zero for vibrations, but the air pressure is produced at the cone and port areas so the force they produce is pretty violent so that pressure wave is MUCH worse and must be avoided. Frankly the amp could be located in places much worse than on the sub box (as you are pointing out) but I am trying not to read too much into this. I think an area with fewer vibrations is a better location, but again I deal with maybe 500 different builds per year and I have never seen a vibration failure but I am not sure that when a failure occurs it has the courtesy to point out why it occurred.

BTW I have seen amps mounted inside the box...

 

I tend to listen to the manufacturers warnings about mounting amps on sub boxes.

My brother had 2 amps die premature deaths. Both were mounted on the box. Both ran 4 ohm loads and were treated quite well otherwise.

Do I know unequivocally that the vibrations from the box damaged the amps....no. But I'm not mounting an expensive zapco c2k on it just the same!

 

True.....on the inside of the box??? Wow, that's a new one to me.

Haha, that kinda puts things into perspective

 

I've mounted an amp inside a box. More than once actually