I was wondering how many channels on a amp I'd need to run 2 speakers front and back and 2 subs in my impreza? Just wondering if I can get away with one?
John

 

You will need 2 separate amps in tri-mode, that is 3 channels per amp, one amp for rear speakers / one sub the other front / one sub. Your setup requires 5 or 6 channels depending on how you prefer , 2 for front, 2 for rear and 2 for subs . Another way is to have a 4 channel amp for front/ rear speakers and a class d mono amp for both subs, personally i would go for the 4 channel/ mono amp setup.

 

4 channel plus the monoamp will be the best, but there are some 5 channel amps out there that will allow you to set one as a mono O/P for a sub, just check that the mono O/P is capable of being two ohm stable.

 

I would have 2 amps. One for my speakers and a BIG powered one for my subs. Try and get a head unit with 2 pre outs. One for each amp.

 

The mono channel doesnt have to be 2 ohm stable for the 5 channel amp if you use 2 4ohm dual voice coil subs. The 5 channel will probably be the cheapest option(well, it depends i suppose),and the easiest to install, but the preferred would be a 4 channel and a mono/2 channel bridgeable amp.

If you can, go for a three pre out unit - it will mean you can keep the fader for the front/rear speakers.

 

genesis monoblock has two positive terminals (linked together) for the output, so you directly run each sub from the amp and they'll be linked in paralell - so two subs at 3 ohm each would give 1.5ohm overall = lots of power from genesis. even my miniblock kicks out 640 wrms at 1ohm.