okay gotcha.. i understand what you are trying to do..
the clarion head unit ...
.... well you get the idea. if you are powering the seperates with the head unit, then the internal amp doesnt have enough power.
when you add aa external amp then the preamp voltage signal needs a bump up from 2 volts... would suggest a audio control line driver or crossover..it will bump the 2 volts to 9 volts.
if you need to power all 6 speakers, then you can run a 2 channel & a 4 channel, 3 2 channel amps or a big a$$ 4 channel amp ( like a jl 450/4) run the 4 cabin speakers (series or parallel) and the 2 bow speakers off the other 2 channels.
to find out ......figure out hyour system design the best you can (take into account future) and just talk to people here and local stereo shop
btw, boat speakers need at least 75-150 watts of very clean amp power (jl, zapco)
(Message edited by clubmyke on February 21, 2005)