finally have the pieces to my system (low budget) i have a 04 f150 Supercrew i'm putting 4 5x7 infinity ref in the doors and 1 10 pioneer sub under the rear seat. my question is I have a alphasonik q2150 2 channel amp that will be powering the infinity's is there a way to wire this up so that i can power all 4 speakers off of this amp at 4 ohms or would i be better off to just power the front door speakers off of the amp and let the factory head unit power the rear speakers as they are just more for rear fill any way?
If you try and use 2 channel amp to power fronts and rears, then you'll lose the ability to fade. If that is not a concern, then yes it's possible to power all of your speakers with one amp. Connect the front left and rear left in parallel (pos to pos and neg to neg) for 2ohms load. Repeat for right channel. Now take the pairs and hook it up to the amp's speaker output terminals. You will find that 5x7 speakers won't handle much power.
so would you recomend to only run the front speakers off of the amp and use the headunit for the rear ?I know that a lot of ppl on here say that you don't need the rear door speakers but i want to just trying to decide if this which way would be the best for me thnks for your input. and I guess the only way to keep a 4 ohm load would be to run the front speakers only (not sure if amp can handle a 2 ohm load gotta look at specs). by the way what is the difference between wiring in parallel and wiring in series and what would the benefits be?
If you fading is not important, you can use one amp. Wiring in parallel drops the resistence from 4ohms to 2ohms. That will give you more power, and your amp is suppose to be 2ohms stable in stereo mode.