After installing tweeters, coaxials no longer work.

I installed some stock OB tweeters in my wifey's super sick bad ass clean '93 SS. Now the coaxials that sit in the front doors are no longer functioning.

 

Current setup: Sony Xplode HU, two Xplode coaxials in front doors, two 12" Audiopipe subs, Sony Xplode 800w amp, stock speakers in rear window.

 

When I purchased the car it came with the HU, and the Xplode coaxials were hooked up in the rear window dash. I installed the 12" subs w/amp, and let my wife loose to bump as she pleased. Naturally, I wanted it to sound even better (the more my wife loves her subie, the less she will be likely to complain about me spending money on mods), so I nabbed some OB tweeters from the junkyard that fit inside where the rear view mirrors are located. Since the Xplode coaxials should be better than the stock speakers I decided to swap them to the front and move the stockers to the back until I get another decent set of coaxials for the back.

 

When I swapped the coaxials to the front I tested them before I put the door cards back on. They worked and sound was coming out. Next I tapped into the positive and negative wires that feed the coaxials to power the tweeters and tested them and they worked. I put the door cards back on.

 

Next I installed the stockers to the back. They also tested out, and I could hear sound coming out.

 

Yesterday my wife was kind enough to let me ride in her SS, and I noticed that the coaxials in the front were no longer working. The tweeters work so well that it took me a while to notice that the coaxials were not producing sound. The HU also said 'FAILURE' which I am trying to not take personally.

 

All in all, the system still sounds great, but I want the coaxials in the front to function. Any ideas as to why they went out? I will take the door cards off again this weekend, but I would like to hear any thoughts as to why this happened.

I am definitely no expert but it sounds like by tapping into existing speakers in parallel you have created an impedance issue. I am not sure what OB tweeters run for impedance but when you run 2 4ohm speakers in parallel it becomes a 2ohm load and most hu's cannot run below 4ohms.

That would make sense. So should I add a resistor? I guess I need to break out my old physics homework, lol. What would be a good way to fix this?

The HU also said 'FAILURE' which I am trying to not take personally.

 

:lol:

 

That's awesome.

 

Are you running the coaxials off the HU or the amp? Sounds like the HU.

 

Do the tweeters have any capacitors on them? Or are you just running them in parallel off the coax signal? You need to have some kind of high-pass filtering on that signal otherwise you can damage the tweeter.

 

IMHO, I'd try running the coaxials by themselves first, since it sounds like you didn't switch from rear to front with coax only.

 

If you do want to run the tweeters as well, you should wire them in series with the coaxials. Also run a capacitor on the positive line leading to the tweeter. 19.88uf would be the value for a 2kHz filter in a 4ohm system.

Yes, I am running the tweeters off of the HU, and they do have small built in capacitors.

 

I put the exact same tweeters in my second gen and they work fine with no problem. However, there was a tweeter harness pre-wired. All I had to do was remove the door cards and plug them in. I was told that they appear to be wired in parallel with the coaxials, but perhaps the person who told me that was mistaken. Check out this pic of the door card removed with the tweeter harness visible. Maybe it will help, maybe not. It would seem strange that if they are in parallel with the coaxials in this case that doing the same thing with the SS tweeters doesn't work.

 

How do I wire them in series with the coaxials? I'll try it and see what happens.

 

edit: OK, I found this diagram on how to wire speakers in series after a quick search.

Since I pulled the door cards off my second gen today I snapped a pic of how the stock tweeters and the coaxials are wired together.

 

Looks like they are wired in parallel, eh? I could easily be wrong.

Parallel only. If you wired them in series the crossover (capacitor) in the tweeter will prevent the coaxial from playing any frequency below the tweeters. (the coaxials would be virtually silent) It will also double the impedance, causing the speakers to see only half the power.

The tweeter from Subaru plugs directly into a pre-wired plug found in the door. It will be taped to another harness with blue tape. Look at Monkeyposeurs first photo that clearly shows the blue tape.

I took the door cards off and took a good look. I had wired the tweeters and coaxials in parallel as I thought. There is a built in positive line capacitor in the OEM tweeters. The reason the coaxials quit working is that their connections had vibrated loose. I crimped the connections, but apparently not very well. Now they are held fast and everything is working great.

 

I also tried wiring the tweeters and coaxials in series, and like stevenva predicted, it didn't work. Neither the tweeters or the coaxials put out much sound. Once I wired them in parallel everything worked perfectly.

 

And to clarify, first gen Subarus do not have pre-wired harness for tweeters as do the second gens.