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View Full Version : Try this speaker wiring mystery in an e34



Unregistered
06-01-2004, 02:07 PM
I am trying to figure out what is going on with my stereo in my 94 530 wagon.

The previous owner of my car had removed the original amp and the head unit and put in hideous Blau, and wired it directly to the speakers, no crossovers. The guy used the original wiring from the HU back, and tied all (woofer-mid-and tweeter) the front right positives together all the front right negatives etc. It was ugly, but it worked.

Fast forward

I put a new nakamichi head unit in, and an A/D/S 6ch amp. I wired the head unit, with rca to the amp, and I wired the stock tweeters and woofers (left out the mids) in the front throught a set of crossovers. I replaced the stock rear speakers with a set of Boston components and used the boston crossovers. According to what I've read, the BMW amp has internal crossovers.

Since the factory amp is no longer in place, I figured that I'd need crossovers for all the speakers. So everything is wired up with external crossovers, but when I play the radio it sounds like I'm listening to it through a pair of headphones on the dash. the signal is there, but it has no power at all.

The amp is good, I have tested it.

From the wiring diagrams it looks like the factory speakers are wired in series/parallel, but I'm having a hard tome figuring it out.

Does it sound like I'm overlooking something, or wiring the speakers wrong?

Any help is appreciated.

Hallmark
06-01-2004, 02:42 PM
Check to see that all of your positives leads are going in to the same side of each speaker/crossover, especially on your new speakers in the back. If they are out of phase the sounds will cancel each other out to an extent, especially on the bass end.

Also, have you checked to see what the impedence of the new speakers is? They need to end up balancing with the existing speakers.

Tiger
06-01-2004, 05:36 PM
reverse your + and - on one speaker to see if that correct your problem... at the crossover you used.

Unregistered
06-02-2004, 10:48 PM
If so, I'm not sure mine do. Would this cause this type of problem?

Thanks,
Matt

Hallmark
06-03-2004, 09:32 AM
you will at the least have completely different sound levels from each speaker and, at the worst, you will overdrive your amp and blow it out.

The standard for virtually all major auto sound systems is 4 ohms but auto manufacturers are notorious for using speakers made to other standards (I've seen everything from 2 to 14 ohms from factory speakers). Doing that insures the stereo system only works right with the original equipment head unit and amp. Check the new equipment you just installed and you will most likely find that its power rating is given based on a 4 ohm load.

Each speaker should be stamped with the ohm rating on the back of the voice coil. You can change the speaker resistance by putting a resistor in series between the leads, but which resistor depends on what the rating of your speaker is.

dca
06-04-2004, 01:51 AM
this seems to me, you've conencted your head unit wrong. or amplifier. I do not think that you are facing a phase problem. if it was so you should be able to hear loud sound but no bass or surround sound effect in cabin.

best thing is to connect a speaker to each channel of your head unit. if everything is ok then just conenct your amplifier. then check each channel of your amplifier.

this should help you to diagnose your problem. one by one at each trial you will get close to your solution.

ps:there might be a option on your head unit to set your system in right way. check everything once more.