OEM headeck to Alpine amp?

I recently had my brand new 2006 Pacifica worked on to have the door speakers replaced with Polk MOMOs driven by a 4 channel Alpine (MRP-F450), and a single JL 10W3 driven by an Alpine mono-block (MRP-M450).

My question is this.

The installer took the speaker level inputs from the factory amp, and ran those into an LC-502 high to low level converter and then to the Alpine amp. He stated that coming off the factory amp (factory 200 watt (this must be peak not RMS)) would be a cleaner signal then coming straight off the factory headeck, and then going direct to the Alpine high-level inputs. I am not sure I agree, and am wondering should I pull out the LC-502s and just wire the Alpine directly off the feed coming straight from the headeck to the high-level inputs. Or is he correct and I really should be using the signal from the factory amp, and then run that into the LC-502 converters then go low-level into the Alpine.

I guess I am skeptical that the LC-502s would convert the high to low better then the Alpine, and I am also skeptical that I am not introducing more distortion by using the signal after it has passed through the factory amp, and not just use the minimally amplified signal direct from the factory headeck.

What do you guys think I should do? I really would like to get to the bottom of this, and learn from this one way or the other.

Thanks

Scott

he was correct, nuff said

sS

If your deck feeds a low line signal into the factory amp, you can often run that directly to your new amp's low level inputs.  Otherwise you can take signal after the factory amp and use a high-low converter to feed your amp.  It just depends on the situation- sometimes the factory amps have built in eq curves/crossovers to help compensate for the poor speakers that come with the car.  So sometimes it's best to get your signal before all this extra processing takes place.  Other times you'll want to take advantage of a crossed over signal- possibly like hooking up your 4 channel.

However, it's best not to use an amp's built in high level inputs- they're typically garbage.

Ok, that sums that up.  I came up with all of this since what I am getting out of the system now is distorting and just plain doesn't sound right.  Highs too high, missing mid, and the bass seems to distort the entire system.  I guess it is back to the drawing board with gains and LP/HP filters. 

Thanks guys for clearing this up for me.  I figured he was right, he is a good installer.

Scott