Amp & speaker upgrade 2003 G35 Sedan
 

Let me just say right off the bat. Bose sucks. ALL Bose suck. I've been around car stereo since the 80's and I've heard some really crappy car stereos, but this Bose is the worst possible junk. The highs and mids sound like a fart through a dirty sofa cushion. 1948 transistor radio speakers in a heavily EQ'd system, pathetic at best.

Ok now I've searched all the threads and as usual they get people not knowing what they are talking about or calling parts and components by the wrong name. But there's always the 1 guy that really knows what's up and that's the guy I'm looking for. So here goes.

I replaced the front door speakers with Infinity 6030CS component. Mounted the tweets in the stock location with a little modding to aim them in the right direction. It was a no brainer and took less than 2 hours. Sound improved but nothing to get excited about. My Alpine/Boston/JL Audio in my Ford Explorer absolutely blows this away in both clarity and 139db SPL

So what I'm thinking now is the Amp with it's EQ is the problem. I'm thinking about replacing it with a 5 channel amp. What I want to do is keep the stock harness from the HU and before it goes into the amp, add some RCA connectors and go line in the new amp. Then use the stock speaker harness. This will work I assume. If it won't, please explain why

Dan

You're right that the amp is the real problem. The headunit outputs a clean *differential-balanced* signal, so unless you replace the headunit you'll need an amp that is built to accept a differential-balanced signal, otherwise, you're going to only be getting half the signal. There are very few 5-channel to choose from, and even fewer of them accept differential-balanced signals.

All JL Audio amps take differential-balanced signals, there's a few others out there, but it's more of a model-by-model basis rather than a company's entire product line.

With an '03, you're (sorta) in luck - the 03 sedan woofer has its own amplifier. So you can give a four-channel amp a try. If you're ok with it powering the doors and the stock woofer amp doing its own thing, you're done. If you want more from the weaksauce bose woofer, bypass its amp, and use two channels of the four-channel amp to power the woofer, and only power the Infinity speakers up front, rear speakers aren't worth bothering with. Front soundstage is more natural anyway - who listens to music standing in the center of the band? Nobody except the band. Music is mastered to recreate the experience of them standing with the band in front of you.

So, using the stock wiring from the headunit to the trunk and from the trunk to the speakers is just fine, but the stock sedan amp location isn't the greatest (coupes on the other hand can handle good-sized amps in stock location), so you'll have to extend the wires and mount the amp elsewhere, or get a small D-class amp that can fit in the stock amp location under the rear deck. You'll still need to run power and ground wires to the amp, but it's fairly easy in these cars to make it invisible.

Frustration is starting to set in. PM sent to you Wrathernaut