I've got an Alpine 7854 HU. Unfortunately it has only one preamp out. I need to power four door speakers and a 10" sub with HP and LP capability.
Am I correct in assuming that because the RCA preamp out offers no fader control, I'm better off buying a 4-channel amp (as opposed to 5-ch) and running the door speakers in 2-ohm mode (front & rear connected) and the sub as a bridged 4-ohm speaker?
Alpine 7854 CD Receiver
(amp inserted here)
4 Polk DX7s 6x8" (4-ohm)
1 Polk GNX104 10" sw (4-ohm)