Making room for both amps.......

The underside of the seat has plenty of room for one amp, but the second amp would not fit stacked on top of the first. There is almost six inches of clearance at the front of the seat, but only about 3.5 at the rear. Each amp is around 2.5 inches tall, and a plate has been made to stack them on top of each other. The total height is just over five inches.

A cutout has been made in the center of the seat to create room for a notch, to allow clearance for the current 3404, or it's replacement with another 5604 or similar sized amp.

I could have reran the wiring, and put the second amp somewhere else, but it's cleaner to have it stacked with the first. There should be about an inch on each side of the lower amp, a 1/4inch between the two, and I will make an acrylic plate to go on top of the upper amp to push the seat material up, when the seat is down. This will make it look clean when the seat is raised.

To make the underseat plate, I used an aluminum shelf from a two-post telecom rack. It just happened to be the correct width, and shape that I needed. A little bit of trimming, and a couple of screws, and the notch was made. The foam is a little thin towards the back of the seat in the middle now, but I dont sit there, so it's not a problem.