Lost in Amp Translation

[tcgg]

I need some help understanding the designation of the different pins in the HK amp connectors in my '98 M roadster.

I'm going to try and install a new amp using the existing wiring. I'm not enough of an audiophile to go through installing new wiring if it's not absolutely necessary.

I found this listing of the connectors and the pin descriptions. I'll put what I know or what I'm guessing beside each one. Can anyone confirm/fix what I enter and add what I'm missing and/or answer the basic questions under each pin listing?

As usual - thanks for the help.

Any advice is welcome as I try my hand at car audio for the first time.



pin function wire color
--- -------- ----------
1 12V red/white
2 on/off white
3 ground brown
4 ground brown
5 RBLO+ blue/purple-Right Back Low Frequency Positive
6 RBLO- blue/gray -Right Back Low Frequency Negative
7 LFLO+ yellow/red -left Front Low Frequency Positive
8 LFLO- yellow/brown-Left Front Low Frequency Negative
9 RFLO+ blue/red -Right Front Low Frequency Positive
10 RFLO- blue/brown - Right Front Low Frequency Negative
11 LBLO+ yellow/gray - Left Back Low Frequency Positive
12 LBLO- yellow/blue - Left Back Low Frequency Negative

(QUESTION - Are these the inputs from the head unit)

J2 26-pin Siemens connector

pin function wire color
--- -------- ----------
1 RB- IN blue/gray
2 RB+ IN blue/purple
3 LB+ IN blue/black
4 LB- IN yellow/brown
5-7 n/c n/c
8 RFHI+ yellow/red (LTwtr)Right Front High Frequency Positive
9 RFHI- brown/orange (LTwtr)Right Front High Frequency Negative
10 LBHI+ yellow Left Back High Frequency Positive
11 LBHI- brown Left Back High Frequency Negative
12 RBHI+ blue Right Back HighFrequency Positive
13 RBHI- brown Right Back High Frequency Negative
14 RF- IN blue/brown
15 RF+ IN brown/black
16 LF+ IN yellow/red
17 LF- IN yellow/brown
18-20 n/c n/c
21 LFHI+ yellow/green (STwtr)Left Front High Frequency Positive
22 LFHI- yellow/brown (STwtr)Left Front High Frequency Negative
23 RFHI+ blue/brown (STwtr)Right Front High Frequency Positive
24 RFHI- blue/green (STwtr)Right Front High Frequency Negative
25 LFHI+ yellow/blue (LTwtr)Left Front High Frequency Positive
26 LFHI- yellow/gray (LTwtr)Left Front High Frequency Negative

(QUESTIONS - Are these the outputs to the speakers? Why the duplication - e.g. two sets of LFHI+/LFHI-)

J3 6-pin AMP connector

pin function wire color
--- -------- ----------
1 GAL IN black/white
2 SPATIAL n/c
3 SUB LO n/c
4 GAL OUT n/c
5 SUB OW n/c
6 SUB HI n/c

[Monolith]

what you want.

The BMW crossovers are built into the BMW amp. Most likely you'll end up with an aftermarket amp without built in crossovers and will have to install those next to the amp somewhere. They usually are quite large. Running wiring really isn't too hard. I only use dash mounted tweeters and kickpanel speakers (I don't use the door speakers at all). My crossovers are mounted under the dash above the footwells.

[Monolith]

1998 BMW Z3M Wiring Diagram

[tcgg]

I really appreciate the diagram. It will help a lot - if I ignore your wise counsel in the first post and decide to try it on my own.

I didn't mention that I bought a set of Alpine component speakers a while ago just for the 5 1/4"s for the footwells. Your message made me go back and look and, sure enough, the speakers came with a pair of 2-way crossovers and they are relatively small.

I see 2 reasons not to do it myself:

1.) getting the alpine tweeters installed in the doors replacing the 2 stock speakers there

2.) figuring out how to get the wiring from head unit to amp and back to speakers and making it look good without spending too much time on it.

If I do it will be a learning experience whether I complete it myself or have to ask a local shop to finish what or have to yell HELP and ask a local shop to complete it for me.

thanks again - Tom

[tom_m]

If not it's all new cabling.

Tom M.

"All of us get lost in the darkness
Dreamers learn to steer by the stars
All of us do time in the gutter
Dreamers turn to look at the cars" - N. Peart

[MikeinNH]

An expert named Bob Hazelwood who worked for a/d/s here in New England advised that using the speaker wire already installed was the smartest thing you could do (check the archives). I installed new speakers, and placed the crossovers on a piece of thin plywood on the mount where the old amp had been, and ran the OE speaker wire from the new crossovers to the individual speakers - it's worked great!

[MemphisTomC]

The radio gave out about a year ago and I installed a JVC from Crutchfield. It came with an adapter so it tied into the existing wiring harness.

So with the new head unit and now a new amp I guess I do need to run rca cables from the JVC to the new amp then pick up the old speaker wires?

I've read about running the cables through the central console and through the subwoofer area and into the trunk.

I don't want to oversimplify this but am i missing anything major?

[MemphisTomC]

That cuts a lot of my work down. Thanks Mike

[Monolith]

The only thing to watch out for is the car's main power wire when running speaker wires (they run down the passenger side of the car). So, it's best to run the speaker wires down the driver's side. Since you're using the existing speaker wires, you don't need to worry about this.

There are two rubber grommets in the rear deck - one on each side of the car. The passenger side has the car's main power wires running through it. I would route any additional wiring through the driver's side grommet (to keep them away from the vehicle's power wires).

I believe there is a capacitor used as a filter in the door panel. I would bypass this if you're using the Alpine mid and tweeter combo with the Alpine crossover mounted in the trunk next to the amp.

[MemphisTomC]

I can't remember how the factory tweeters are mounted in the door - to the back of the door panel? Are they screwed in?

If I pull the factory tweeters to put in the Alpine tweeter - can I use either set of speaker wires inside the door panel?

[Monolith]

One for the tweeter and one for the mid. You just want to make sure there is no filter going to the new tweeter. If the mid wiring goes although way to the rear amp, you'll just not use those wires.


.com/forums/showpost.php?p=3845005&postcount=58]Ron Stygar's Door Removal Pics

[Monolith]

http://www.bimm****.com/forums/showpost.php?p=3845005&postcount=58

Type in "erfest" in place of the asterisks above.

[MikeinNH]

First off - you have a schematic, right? Don't cut anything until you know what all the wires in the amp plugs are for and can identify them. There are six speaker wires on each side for the front speakers - one set (+/-) each for a tweeter, midrange & woofer. Your new tweeter will most likely fit where the OE midrange is - see the link to mz3.net, the third picture down is what you'll have once you get the door panels off. Remove the midrange and secure your new tweeter in that mounting bracket (I did mine the same way DC did in this article, and it worked perfectly). Simply disconnect the OE tweeter at the amp & leave it in place - you don't need it. When you hook up the new speakers to your crossover, just use the respective wire set for the woofer & the midrange (which is now your tweeter).
Word of advice - when you've taken a deep breath and decided to start cutting, leave some wire attached to the amp's plugs, in case you ever want to return the car to it's stock configuration - don't cut right next to the plug. If you ever go back to stock, for whatever reason, you can use butt connectors to re-attach the amp plugs. I saved all the pieces, just in case... Hope this helps...

[MemphisTomC]

Thanks a lot!

I did as suggested using the placement of the door midranges for the new tweeters.

I cut down the mounting brackets for the OEM midranges to hold the new tweeters and that worked fine.

I have a Bentleys manual so I used the wiring diagrams and I think I have the new tweeters wired correctly.

I can't test it though because I don't have a working amp yet.

thanks again for all the advice!

Tom

[MemphisTomC]

I bought a new Alpine MRP F300 4-channel amp from Crutchfield. I'll live without the subs for a little while.

I took out the 2 speakers in the door and put in the Alpine tweeters from the component set wired to the larger door speaker wiring.

I ran RCA cables from the trunk into the soft-top well and under the console to my JVC KD AHD-59 radio.

I'm going to try using the existing speaker wires and the connectors they attach to as well as the existing on/off wiring from the radio. To do that I took a section of speaker wire for each channel and soldered the pins stolen from the amp to the end of the speaker wire. I can then plug those pins into the existing connectors.

I am using channels 1 and 2 to power the door speakers and channels 3 and 4 for the footwells and the 4" Blaupunkts behind the seats.

I hope to actually power it up tomorrow and hold my breath when I turn the radio on.

thanks to all for the help.

I'll let you know what happens.

[MikeinNH]

Maybe I missed something, or I'm misreading your info. Did you install a new component speaker set (woofer, tweeter & crossover)? If so, your amplifier "front" channels (1+2) should be wired to the inputs on the crossovers. Then hook up the set of wires from your new tweeter to the 'tweeter' output on the crossover. Next, hookup the set of wires from the woofers in the footwells to the woofer output on the crossovers. All 4 of these speakers should be run from the 'front' amp outputs via the crossovers. Next, hookup the 4" Blaupunkts to the 'rear' amp outputs (3+4)... Make sure to keep all the speaker sets in phase ("+" on the amp goes to "+" on the crossover, which goes to "+" on the respective speaker). I think that'll work better for you! I'd also set the amp crossover on channel 3/4 to "HP" and at least 50hz, to avoid overworking the Blau speakers...

[MemphisTomC]

Thanks Mike

I'm a little confused and you seem to be one who can clear things up for me.

The Alpine amp has crossovers built in, right? Don't they split the signal the correct way?

So you're saying that I should have a full range signal come from Channels 1&2 and let the crossovers split it between the tweeters in the door and the mid-ranges in the footwell?

Then set channels 3 as you suggest, to get a full but not overpowering signal to the Blaus.

It sounds simple but I thought the amp would split the signal adequately.

Back to the trunk tomorrow.

thanks again

Tom

[WB-MZ]

I agree with Mike about going through the Alpine crossovers, but have you thought about bridging the amp channels 3 and 4 to drive your sub and either forget about the 4" rear speakers (they're almost worthless any way) or if you have to have them drive them from the head unit.

[MemphisTomC]

Can I bridge only channels 3 and 4 and leave channels 1 and 2 unbridged?

Can I run the rca's from the head unit to the amp and still run the two 4" directly from the head unit?

[MikeinNH]

If you're running the stock subwoofer, I don't know if giving it the 150 watts from your Alpine amp would work or not - it may not be able to handle that much, and, I don't know the resistance of the OE sub - that Alpine isn't rated below 4 ohm in bridged mode, so you do that at the risk of frying the sub and/or amp (unless someone else has that info). I suspect the two-driver BMW unit is only 2 Ohm, but I'm not sure. And yes, you can still run the Blau's off the head unit, if you choose. IF you decide to try the sub off of the amp, bridge the channels and set the crossover for 3/4 to "LP" and set the dial somewhere between 80 hz -100 hz to start. And set the gain low, and bring it up slowly... Personally, I'd run the rear Blau's off the amp unless you know the resistance of the sub, but you're driving...
P.S. several folks have commented that having good rear speakers, properly powered, made a significant improvement in the bass. I may add rear speakers myself someday).
Regarding your earlier question, the amp does have crossovers, but they weren't intended to to separate the frequencies between the tweeter & woofer - the crossover provided with the speaker set is specifically designed by Alpine to separate the woofer & tweeter at the optimum frequency.
You're almost there!