Q about connecting 2 amps to a deck...
 

Hey guys,

I'm getting ready to install all my stuff this weekend and wanted to ask you opinion on the best method of connecting both of my amps to my deck.

List of equipment:
Pioneer DEH-P80MP
Phoenix Gold Xenon x400.1
Alpine MRP-f450
Infinity Reference Speakers (6.5" components front and 6.5" coaxs rear)
2 x Infinity Reference 1030w subs

My deck has 3 sets of preouts, and my 4 ch amp (Alpine) has a 2 channel output which sums the 4 channel inputs by combining the F & R left channels and F & R right channels.

My question is, in your guys experience or opinions, would it be better to run the all channels using the preouts on the deck, or better to run 4 channels to the 4 channel amp, then run the summed signal to the monoblock and use a remote gain attenuator on the monoblock to control sub volume?

Also, regarding crossovers... I was planning on running everything on the deck as full range (all crossovers off) and utilizing the crossovers on each amp to tune. But would I be better off running the amps with all crossovers off and running the crossovers on the deck instead? The internal crossovers are selectable at 50Hz, 80Hz, and 125Hz only. (I am unsure of the slope)

I am thinking that the amps crossovers will offer more tweakability, but I don't want to diminish SQ if the decks crossovers are higher quality.

Thanks in advance for your opinions.

I would use the preouts on the deck so you have control at the front!

^^^ I take it you're talking about sub volume? Wouldn't this be the same as using a remote gain attenuator for the sub amp?

Yes,but you can also fade front to rear etc

Oh yes I was going to be able to retain this control anyways, maybe I wasn't clear enough.

As opposed to connecting all channels to the deck I was thinking about connecting the 4 interior channels to the 4 channel amp and then using the output on the 4 ch amp to run into the monoblock. Basically sending the sub amp the combined front and rear channel signals from the 4 channel instead of from the head unit directly.

either way is fine, but I always like to have all the rca's represented at the rear(run all 3 pre-outs), that way if I decide to add more amps or a processor, I have all input signals ready to go without having to re-run wires.
As far as the cross-overs, it's always easier to tweak from the driver's seat. If the amp's xo's are more versatile then use those, but if they're similar then use the head unit. Quality should be similar, and should not be a factor as your equipment is of good quality.

Seems to me it would be more proper to run all the rcas to the back, instead of daisy chaining off another amp. It’s just another component that has to do some processing on the signal. And again have all your controls at the deck.

I think it may also be better in terms of groud loop problems. Signals grounded at more then one point.

OK thanks for the input guys. I will run all 3 from the deck and use them as full range out then use the x-overs on the amps because the amps x-overs are variable whereas the decks are fixed as mentioned above.

I will though for kicks just run a small patch chord across from the output of the 4ch amp to the mono block once its all in just to see if there is an audible difference.