my friend had two 12s STUFFED behind the seats of a std cab.
Ya, the sound was there but he always ran it turned up.
I haven’t talked to him in a while but I am thinking he probably would be able to hear me anyway… lol.
"I am no audiophile, just want a little bass to balance things out”, but I would think if you find out the volume of space needed by each speaker and kept that to a mid size you could build an enclosure that would work behind the seats.
Again, I am buying my, $30 with the volume I need for my 10”.
Here is the page from the site I like to use. I am sure there are better units but for the prices they offer I think it is a deal.
If I get it before you finish I will let you know.
http://www.sonicelectronix.com/cat_i208_10-angled-truck-sub-boxes.html