Hey !
My Saltare tower setup : https://forum.supraboats.com/showthr...-tower-speaker
HLCD on page 3

Running a Soundstream pn4.520d for the whole boat. 2 channel on the tower, 2 channel for 4x 6.5'' Boss marine inboard speakers, and sub channel on a MTX RT12-04, home made box.

Very efficient configuration, on a budget.

If I change something, I probably would go for 3 new class D 2 channel amp to get more power on the sub and on the tower.

As source, I have a car Pioneer CD/SD/USB radio, with the wire marine remote. Doesn't exist anymore unfortunatly. One important thing : go for a source that has 4 volts or more RCA outputs.