Aftermarket Sony + factory M&T amp + 4 ohm speakers? How to connect?

[DeLaMano]

Hi all! I've done a bunch of trolling through the forums, but I'm still a little unclear about what to do or what I need. I want to install a Sony MEX-BT3700U head unit (52w x 4), and I just got two pairs of Polk Audio db651's to replace the factory speakers. I wanted to get your guys' (gender neutral) opinion on how to hook it all up: Should I go with speaker level outs from the HU to the factory amp (with a line output converter)? Or line level outs to the factory amp? Or maybe just bypass the amp altogether and run straight from the HU? Seems like a waste to not use the factory amp, though...Any info or advice would be greatly appreciated!Here's the HU, just in case you're curious: http://www.sonystyle.com/webap...55568Cheers from the thawing North country (TFG!),DLM

[DeLaMano]

Well, a little update:Got all the speakers in following cohocarl's how-to: http://forums.genvibe.com/zerothread?id=785 , but not without some finagling. My '03 M&T has some pretty cheap speaker mounts in the front and the Polk Audio db651's I got based on the comments here did not just drop in. I had to shave the outer ring of the plastic mount so that the speaker would fit. Even now, the tweeters hit the grille. Maybe just have to use the grilles that came with the speakers.I wired the HU to a Metra wiring harness, but wanted to avoid all the output attenuator business and so decided to splice in some RCA plugs to go off the preamp outs from the HU. Now I have the dreaded "POP" every time I change sources (CD to Tuner, etc) or change radio stations. (Maybe that's what the white "mute" wire is for in the C2 plug?).Probably just have rewire with the speaker outs and get the line attenuator...

[coldfusion11]

When I installed a pioneer radio in my friends 2003 vibe MT, Crutchfield sis not say it needed an attenuator adapter so I did not use one and connected everything up like normal. Well about 7 months later the amp blew.Now Im just going to rewire the speakers manually from the HU to each speaker myself.

[DeLaMano]

In the end, I just wired everything normally at the receiver harness. Then I unplugged everything at the amp, spliced the line level in's to the speaker level outs (so the signal goes straight from the HU to the speakers), and I slid in an RCA cable from the Sub out on the receiver to the sub behind the driver's seat. The factory amp could be removed altogether, I suppose. I did lose my factory tweeter signal (crossover is apparently in the factory amp), but I found a pair of Hafler tweeters with crossovers to replace the factory tweeters, anyway. Long and short of it is that everything sounds great, and I have hands-free Bluetooth through the HU. Safety first!!