The amp is an old Alpine 3522S $5 garage sale purchase. It is running bridged mode mono, LPF is 80hz, signal input is from the left rear factory car spkr to SP Level Mono input on the amp, amp gain is set about midway. The car stereo Fader controls the relative output to the AutoTuba. The amp is at most 25 or 30 watts.
This less than optimal hook-up is fine for testing/break in purposes. My guitar player heard it and wanted to hook it up to our band PA! The bass player heard it and began shhss'ing me so he could hear the bass lines. He was hearing notes he'd never heard and couldn't believe it was a $35 driver running off a 30watt amp...
It will go very loud and is very clean at the same time. This one's going in my daughters Saturn XL and I'll be building another one. I can't imagine how good it will sound with a modern amp and some real wattage (even though it doesn't need any more watts!!!)
