I have the following gear going in my 2009 Fit:

Pioneer FH-P800BT HU
Diamond S600s components
Diamond D3 10" sub
Diamond Hex 700.4 amp

I had originally thought that "obviously" I would replace the speaker wire but now I'm starting to wonder... from looking at the service manual it appears that the wires from the door speakers and the tweeters all lead to the area right behind the factory head unit. It would certainly be convenient to place the crossovers in this area and reuse the existing wires. As I'm sure you can see from my equipment list, I'm not trying to set the world on fire in terms of car audio. At the same time I definitely want things to sound much, much better than stock and I don't want to stupidly skip anything just because it's easier. The guy at Diamond said most OEM wire is 16 or 18 gauge and that they recommend 16 gauge for the components. So am I really buying anything other than work by going with aftermarket wire?

Thanks!
Jeff

 

i suppose if the wires separate behind the HU that would be convenient, otherwise just run the woofer stock and a new wire to your tweeters in the dash.

 

I guess I won't know for sure until I get back there, but according to the schematic and photos in the Helm online manual there is a connector right behind the factory HU that converts from the single pair of "left front" and "right front" wires to two pairs going to the separate woofers and tweeters...

but in general you guys don't think I'd be killing the performance by using the stock wiring? I haven't seen it yet so I have no clue what gauge it is...

 

for setups up to about 50watt RMS i dont think it makes any difference. it's a fairly decent conductor they use.

 

So using your number then, it would seem like perhaps not the best idea for me? I'm looking to have 100 - 125W per channel going to the components. Now granted that would be split between a woofer and tweeter, but doesn't the woofer pull most of that?

 

I was also going to run new wire. I had planned on running 12g speaker directly from the 4 channel amp into the doors. But I was too lazy to do it. I didn't feel like hiding it all, and refused to have a half-assed job in my own car. So i stuck with the stock 18g. My system sounds good enough for me!

 

MetalFit630,

Can you give some more details on the rest of your system? Are you running components? And how much power are you putting through that factory wire?

Thanks!

 

I used the adapters that came with the speakers that I bought from Crutchfield. I plugged the adapter into the plug from the stock speaker and ran that wire to the crossover. I used 16 gauge wire for the woofer and tweeter and ran those to the crossover. I mounted the crossover in the door. I was able to screw it into a square plastic piece on the door panel. I would say that it sounds thousand times better than the stock setup.

 

I was wondering about this too today. My plan is to run Infinity Kappa Perfect components up front with either a Fosgate or Alpine amp pushing about 100 watts RMS. Originally wanted to run speaker wire from the amp back to the HU wire harness and let the stock wires do the rest...

I am hoping the stock wires will be enough to push the speakers because I don't think I'll be close to making them handle all 100 watts anytime soon. Plus, I would rerunning all the wires would be a big hassle for minimal gain if any.

What do you guys think?

 

where are you guys mounting the amps? wouldnt that mean running the wire from the amp to all the way back to behind the headunit? thats a far ways

 

Also worry about the friction contact type connectors used for the wiring/speaker terminal interface. Particularly over time (metal air metal spark gap = carbon buildup). Solder the wires is the near impossible solution. Gold plated connectors is a big help.

For car audio you should use 12 gauge wire up to 30-foot runs, 14 gauge wire on runs up to 20 foot and 16-gauge wire up to 10-foot runs. This based on a 4 ohm (resistance) speaker load which used to be typical for the average car speaker. Many home theater systems use 8 ohm or higher speaker loads. Higher ohms = less current so you can safely run the same guage wire on even longer runs than the above figures without loss of sound quality.

Remember speakers are fairly efficient, 92 db spl at 1m for 1 watt of 1 khz sine wave input power. The other 99 watts is used only for a few milliseconds when the dynamic peak comes along. The current is flowing both ways, being resorbed back into the amp (the amp's Q) when the field pushing the driver's voice coil away from the permanent magnetic field switches. i.e. the + direction collapses, inducing an emf in the voicecoil and thus a current in the wire and then again in the - direction. One of the reasons an amp gets warm. So you are correct in being concerned about the guage of the wires.