Oem harness has dash/door in parallel but new head unit says 4 ohm min.
 

Hi guys, I'll try to keep this short.

I'm planning in installing an aftermarket deck in my '90 Mustang GT (just a big hole right now left by previous owner). The oem harness has the dash and door speakers in parallel. Previous owner left 3" 4 ohm 15/30W in the dash and 5-1/4" 4 ohm 40/80W in the doors. He used the oem harness. That's 2 ohms per side at the deck. Every deck I've looked at says 4 ohm min. I've narrowed my choice down to Pioneer DEH-2800MP or Sony CDX-GT200 (I'm on a tight budget). Both are about 20/50W.

How can places like Crutchfield sell an adapter that plugs into the oem harness when they know speaker loads will be below spec, or is it not that big a deal? Is running the two in series and option?

Although not ideal, many people have had this very arrangement with few problems. I would avoid trying to rewire in series.

Ideally I would consider a small amplifier for the door speakers (or both the door and dash) or changing out to a component set.

Thanks Paul. Why avoid series wiring? I'm an electrical technologist (strictly industrial control stuff). I understand the theory, just not the practice of audio stuff. It's been a while since my last electronics course.

Ideally I'd have more dollars in the budget and gut the whole thing and start over. But it is what it is and I'm trying to get the best I can out of it.

A local audio vender suggested an amp too. I asked how they deal with 6 speakers and only a 4 channel amp. He said they wire the dash and doors in parallel. Are amplifiers more capable of handling the lower impedance setup?

i usually find using a 47 or 22 uf cap on the small speaker works for me with no problems

SERIES WIRING IS THE DEBIL!!

Seriously, avoid it almost at all costs. Especially when there are passive crossovers in the mix (the tweeter on the coax has a cap on it) it does funky stuff.

Almost any car amplifier will handle a 2ohm stereo load with no problem. Even a little 30x2 that you find used for $20 would really snap up the front end. I understand all about budgets though. :ohwell:

Thanks again Dukk.

FYI, I asked Crutchfield tech support the same questio. They just replied, saying the Pioneer will work frine with the 2 ohm load up front.

Thanks for the help fellas.