4 channel amp wiring, tie back into stock wiring, or all new runs?

[philrab]

I have a JL 320.4 to wire up for my door speakers, about 60 watts rms per channel. The question is, I'm waffeling about how to wire this thing to the door speakers.

A. I do it the hard/long way, run all new wiring from the amp directly to the speakers. Intuition tells me this is the better way, but involves relocating pins/drilling through Mazdas Molex connectors at all four doors (huge, hairy PITA). I'm also back and forth because the stock wiring is all 16 or 18 gauge, and 18 at four ohms will easily support 60 watts per channel, so there may not be anything to gain by going this route. I really DO NOT plan to put a bigger four channel amp in, otherwise I'd just suck it up and do it.

B. Run four runs of speaker wire from the amp, up behind the factory radio, and tie into the stock wiring from there. MUCH easier, simpler, doesn't involve monkeying around with the molex connectors, eaier to reverse if I ever need to, ect. This method has a lot going for it, except that I'm relying on the factory wiring to deal with the extra power (even though it should be able to without an issue).

Common knowledge amongst the guys at www.mazda3forums.com that have been down this road is that at the power level I'm running, there's little to nothing to be gained by beefing up the wiring and running new wire. What's your opinion guys? If the hard way is the best way, that's where I'll go, but I hate to think I'm beating my face against a wall for no gain in quality/sound.

[pioneerforlife]

It may be a bit harder, but I would run all new runs and with at least 16 gauge wire. That way everything is separate from the stock wiring. That's what I would do.

[SWIFT]

The stock wiring is totally fine to tie into when running components or coaxials off a 4 channel. They have it all ran safely and the wire is normally thicker copper and can carry the current no problem and is setup to last a long time.

[Broke_Audio_Addict]

If you're going to tap into the wires I would run 14ga to just before where they enter the doors and tap in there not behind the radio. Best to eliminate as much factory wiring as possible that way if you have any isuses in th future you know it's not because of the factory stuff.

[philrab]

If you're going to tap into the wires I would run 14ga to just before where they enter the doors and tap in there not behind the radio. Best to eliminate as much factory wiring as possible that way if you have any isuses in th future you know it's not because of the factory stuff.

That sounds like a good middle of the road option. I'll see if I can dig up a factory wiring diagram and find the wire colors for the speakers and intercept them there.

The molex's for the rear doors aren't hard to access, but the front doors are way up under the dash, little harder to get to. As much as I like to solder everything, something tells me I'm gonna wind up with molten solder on my skin doing that upside down under the dash, but it does sound like the best solution.

Coincidentally, I got 100' of Sky High 14 gauge for this little project in case I decided to go all the way.

Any other opinions?

[mxracer12]

I used a speed9wire from my 4ch back up to the deck and tied into the factory wires there, it was super easy to do and I have over 100watts to each door and haven't had any issues

[Hugh G. Rection]

everyone around where i live is super cheap, so what i generally do is when i install a 4 channel in the back, i run 4 channels of wire from the amp, i go directly to the rear speakers from the amp, and with the front channels i go from the amp to the original wiring for the rear speakers, then i go behind the head unit and connect the front channel wires directly to the rear channel wires. i haven't had any issues with it, and i only do this in vehicles that lack a factory amplifier.