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Discussion Starter #1
Hello
I am trying to install speakers in STi. first item to go in is factory subwoofer. I thougt I saw a wire under passenger seat so I assumed that was the pre-wired sub output. Now I found out that was actually the wire for seatbelt sensor.
I am under the impression that the car was pre-wired to have a sub. Where is the wire? or was my impression incorrect? I actually have to re-run the wire from head unit?
Also, can someone please tell me what wires are there in the doors? Does it have seperate wires for tweeters? or am I suppose to add crossover myself?
Thanks!!!
 

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The sub is not prewired in any Subaru. I believe you plug it into the wiring harness of the head unit and then have to thread it through the center console to the sub under the seat.

As far as the tweeters, I believe they are prewired but I am not sure about a crossover. That might be built into the stock headunit, not sure.
 

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I put my own speakers in so I can tell you for sure that the tweeters are prewired. As are all the door speakers. The subwoofer wiring I just stuffed it under the center console's plastic cover, I didn't even have to remove the cover. It's actually pretty simple. The factory subwoofer comes with a harness that plugs into the factory harness, so you'll only need to get a subaru harness for the head unit. I got one from Circuit City for $15. Do some soldering and you're done.
 

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Discussion Starter #4
cool.. thanks for verifying this. I was getting a little worried.
I have the factory woofer and it came with the harness. I thought that was for the cars that didn't have pre-wires, so I didn't look at the harness and wires. I guess I do have to use it.
 

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Check the sound of your setup before installing. Typically, woofers have a straight-through signal with the tweeters being filtered on the low frequencies, either through a capacitor or proper crossover. I was going to install the crossover (and by extention the tweeter & woofer) through the factory woofer wiring plug, which is the standard setup to use with factory wiring. When I checked the sound before installing, I noticed the tweeters were abnormally quiet. On a whim I plugged the tweeter directly into the factory tweeter plug, and sure enough the tweeter was the proper volume.

This led me to believe two things:
1) The factory setup has a crossover-type device for the tweeters. This was expected.
2) The factory woofer wiring has filtered out high frequencies. This is strange, but it's the only thing that could explain the ultra-quiet tweeter after hooking the crossover into the woofer harness.

In the end, I plugged the tweeter & woofer in to their respective plugs, and left out the crossover provided with my aftermarket speakers. In my case my aftermarket "crossover" turned out to be 2 capacitors and an inductor, which is fairly shoddy. Subaru would be hard-pressed to use a worse setup, so I used all their factory wiring and clipped up my crossovers for the spade connectors.

If the woofer isn't a straight through signal, this would be bad news for those of us using the factory wiring. I would appreciate it if someone could verify this.
 

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There is no built-in crossover for the tweeter. The service manual wiring diagram for the speakers shows that the tweeter wires branch directly off the woofer wires. They are the same color because they are the same wires. Chances are that you weren't getting any sound from the tweeter when wired to the crossover because you had the polarity reversed. When you plugged it into the tweeter plug it worked, but you weren't getting any proper freq crossover.
 

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I doubt that I had the polarity reversed on the tweeter, since the plugs on the system I bought make it impossible to miswire the tweeter to the crossover (one male/female plug on both the crossover and tweeter). Further, reversing polarity wouldn't affect volume unless you had two speakers plugged in to interfere with each other, which was not the case. Finally I can say that, on the front driver-side door at least, the tweeter wires were not the same color as the woofer wires. The tweeter wiring had 2 striped wires whereas the woofer wiring had only one striped wire in the pair.

Lacking a crossover/capacitor in the wiring diagram, oem subaru tweeters would need a capacitor on the back. Is this the case?
 

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Don't you just love doing stuff yourself. This is why I'm paying to have mine done. :p
 
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