Do i HAVE to bypass stock amp?

[bastianshaw]

just bought a vert that has a really nice alpine HU

NO speakers in the rear and the tweeters up front were not working. After pulling the kick panel covers I found a decent looking pair of (coax?) 5.25 w a tweeter in the middle. These are running directly off the HU w a standalone wire<-----weak!

Ideally I would like to move these to the rear( tweets all around) and run stock premium sound speakers in the front and utilize the stock tweets and have this all running of the factory amp.

Good idea?

PS I also have a fader in the dash, do you think this is why the installer just ran a different wire so he didn't have to deal w the fader?

[bastianshaw]

someone help me

[Gregs///M]

Yes, during installation of new radios the installer will usually bypass the fader switch because no one is certain if the fader will handle the wattage. But i know first hand that it will because I've done it many times (installer for 8+ years.)

I would first check to see if your stock amp is there and it doesn't smell like burnt electronics. Then proceed to wire your head unit to the stock inputs of the amp. Its ok to run the high level output from the deck directly into the low level inputs of the OEM amp. It will be OK. Then wire your speakers to the factory speaker locations. Be sure to wire them all in the correctly polarity.

BE CERTAIN the head unit's blue/white wire is connected to the white wire in the dash. This is the remote turn on wire for the OEM amp. It will never turn on without it.

[bastianshaw]

Yes, during installation of new radios the installer will usually bypass the fader switch because no one is certain if the fader will handle the wattage. But i know first hand that it will because I've done it many times (installer for 8+ years.)

I would first check to see if your stock amp is there and it doesn't smell like burnt electronics. Then proceed to wire your head unit to the stock inputs of the amp. Its ok to run the high level output from the deck directly into the low level inputs of the OEM amp. It will be OK. Then wire your speakers to the factory speaker locations. Be sure to wire them all in the correctly polarity.

BE CERTAIN the head unit's blue/white wire is connected to the white wire in the dash. This is the remote turn on wire for the OEM amp. It will never turn on without it.

Damn dude thanks!
Just say you are local the stock wires
Are present so Im hopin I can just rewire

[bastianshaw]

Damn dude thanks!
Just say you are local the stock wires
Are present so Im hopin I can just rewire

Also, can I just bypass the fader only? Or is that more trouble than it's worth?

[Gregs///M]

One thing to note, is your amp inputs are most likely common grounded. So each negative from the speakers outputs must be connected together.

Also, some Alpine head units are high power. My e30 has all speakers powered through the deck and not the OEM amp. It sounds much better than OEM but it is a high output head unit.

[Gregs///M]

which model alpine?

[German Audio Specialties]

One thing to note, is your amp inputs are most likely common grounded. So each negative from the speakers outputs must be connected together.

Please tell me you are not advocating connecting the decks speaker negatives together...

[bastianshaw]

which model alpine?

Ida x200

So twist all the negs together? I'm confused

[German Audio Specialties]

Ida x200

So twist all the negs together? I'm confused

No, what he means is that the deck grounds are not going to be used at all: but the amp input needs to be grounded. You can connect it to chassis ground.

Again, DO NOT USE the negative speaker leads from the deck AT ALL.

Use the 4 speaker positive wires from the fader (yellow/red, yellow/black, blue/red, blue/black) to the 4 positive speaker wires from the deck.

make sure the white wire that is in the deck harness goes to blue/white on your Alpine and you should be good.

[Gregs///M]

Please tell me you are not advocating connecting the decks speaker negatives together...

Apologies, I meant to say amp inputs not deck's outputs.

Bastian, I am not a fan of common grounded systems. I recommend you follow through with the OEM amp bypass and use the head unit outputs to power your speakers.

You will have to either buy a new set for the fronts, or rears depending on what you want to do with your current set or add crossovers to your OEM speakers. You will find your Alpine's head unit will out perform the OEM common grounded amp.

[bastianshaw]

Apologies, I meant to say amp inputs not deck's outputs.

Bastian, I am not a fan of common grounded systems. I recommend you follow through with the OEM amp bypass and use the head unit outputs to power your speakers.

You will have to either buy a new set for the fronts, or rears depending on what you want to do with your current set or add crossovers to your OEM speakers. You will find your Alpine's head unit will out perform the OEM common grounded amp.

so i cant use the stock tweeters?

[German Audio Specialties]

He is correct, this my spending many hours showing how to do the bypass properly on all amplified E30s...but you said you did not want to use the bypass...

Greg, the speaker system in the amplified E30 is not in any way common grounded, ONLY the input to the amp is common grounded, and very late cars had no common ground at all.

You can also easily use the crossovers and the stock tweeters. Aftermarket crossovers will sound much better but are not at all necessary. The stock crossover is built into the front midrange, it is a basic 6db/oct high and low pass.

[Gregs///M]

Then it would be best to remove the crossover circuit from the OEM amp and use it on your OEM speakers powered by the Alpine HU. I believe Attack Eagle created at DIY for removal of the crossover circuit.

[German Audio Specialties]

Then it would be best to remove the crossover circuit from the OEM amp and use it on your OEM speakers powered by the Alpine HU. I believe Attack Eagle created at DIY for removal of the crossover circuit.

No, the amp is full range. The crossovers are literally wrapped around the magnet and there are 3 wires on the front mid: negative, speaker in and tweeter out.

The tweeter grounds to the stock harness about a foot before the speaker.


Kinda weird, but you will see it on E24, E28 and of course, the E30. All the "Premium Sound" cars were set up the same basic way.