i saw someones system yesterday with multiple subs, and a one was inverted. i've seen it a few times before, so i was wondering what are the advantages and disadvantages of inverting subs?

 

Advantages ...

Looks
Increased net volume (No motor structure occupying space within the enclosure)
Slight increase in thermal power handling

Disadvantages ...

Slight decrease in peak SPL (Less effective piston area)
Increase in mechanical noise
Slight decrease in mechanical power handling

There's not really much of a difference and some drivers have awesome-looking motor structures and baskets, so they deserve to be inverted (i.e. IDMAX)

 

^agreed [img]smile.gif[/img]
If you do an install like the one you mentioned, make sure you reverse the positive and negative wires on the inverted sub so it is out of phase. If you have all three "in phase" and one of them is inverted, it will be working against the other two.