OK--I have a system with 2 Polk db570s in the front and (soon) 4 db 570s rear. The rear speakers are wired serial-parallel (I have to verify this with a VOM, but I'm pretty sure this is the case). So I have 4 ohms in front for 2 speakers and four ohms in back for 4 speakers.
My question: if I get a four channel amp, should I get a 55-60 rms x 4, or do I need to go higher, like 80x4?
I don't need huge sound, but I do want to feed my speakers properly. I was hoping to get a good amp for under $200, but it seems that I can't find a 60x4 under about $250 (looks like no one likes cheap Sonys @$150--I guess you get what you pay for). I'd go used if I could trust that my purchase wasn't driven within an inch of it's life.
If I got a 60x4, the front speakers would be perfect at 60, but each of the rear speakers would be getting 30 (all minus 20% waste/heat, right?). The speakers are 60 watts rms, so I don't know if it's enough to put 30 through them, but I hope so. Conversely, I dont' know if it's OK to put 80 through the fronts--I guess I could turn the gains down if I have controls for each channel front/rear.
I don't need my car to shake going down the street, so loudness/killer bass is not my thing. I guess I just want full sound that I can feel just a bit if I want to turn it up some.
Oh--I thought about rewiring the rears in just parallel to get them to 2 ohms, so that the rear channels get a little more power from the amp (60 at 4ohms could be 75 at 2 ohms in some specs I've read)--but I'm trying not to alter the wiring system, and the speaker specs only list 4 ohms, not 2 (does that mean that the db570s don't want 4?).
From reading the forums, I'm looking at Alpine, Hilfonics, MTX, RF, etc.
I have a little amp driving a sub, but I'm not really counting it much in my design--it's a 30wx2 amp bridged into mono with a 10 inch sub--pretty crappy little sub, actually. I should upgrade it, but the above system comes first.
A side note--it's funny to me that the "blackout mode" on my Apline 9805 head unit turns off the display to give the built-in amp more juice. Is the display that power-hungry, or is the built-in amp just that weak? Maybe both.
Thanks again for your help--your answers on my first question about my system's clipping got me this far.