Z3 Harman Kardon replacement hack-job

[zeBugMan]

Hey all,

I'm pretty much a novice to average when it comes to car audio. I'm about to replace a couple of things to kind of follow up on what the previous owner did to the car, finishing the job. That said, I have a couple questions specific to my case, and even after searching, I wasn't 100% sure about the how-to's of what I'm trying to achieve. I'm trying to use the stock amp as much as possible for the time being.

For context, the PO replaced the speakers behind the seats and installed a new subwoofer (which of course, the stock amp can't drive properly). The tweeters in the door sound fine, and since I don't want to pay a shop to remove the doors (and definitely don't want to do it myself), I planned on keeping them and only replacing the kick panel speakers, since they're blown. (I know, this isn't optimal, but I'm not too picky.) I picked up a couple 2 ohm drivers of a different brand for the kick-panels hoping they should be pretty much drop-in. As far as I know, the stock speakers are also 2 ohm, so impedance should match. Does this seem reasonable?

I'll replace the headunit. I have the harness built so this should also just be plug-and-play, hopefully.

The biggest question that I want to better understand is the subwoofer. The PO put in a 6.5" 4 ohm Kicker sub and wired it to the factory wiring. I have a single channel amp I plan to use to drive it, but if possible, I want to do as little modifications to the factory wiring as humanly possible. Ideally, I would love to just disconnect/cut whatever wire(s) go to the sub from the factory amp and reroute them to the new dedicated amp. How feasible is this? In my head, I don't foresee any issues, but I'm not sure what problems I may run into.

Thanks!

[delvec]

You said the PO replaced the rear and subwoofer and the stock Amp can not drive properly?

You may want check your wiring....The single sub should have two sets of wires (Red+/Black-) and (Green +/Gray-). If you have the 6.5 " Kicker Dual voice coils the (Red/Black) goes to one coil and the Green/Gray) go to the other.

The rear speakers have a solid green and a green with black stripe. The Solid green is negative and the Green with Black stripe is Positive....Yes green/black positive. I initially wired this the other way and when I corrected it the sound was better with no distortion.

I just replaced my head unit, sub (Kicker dual voice),rear speakers and kept the factory amps. I'm sure new amps would be great but the factory Amps still cranks it out for me.

[z3forlife]

You can run a new sub wire easily from the enclosure the sub box mounts in to the trunk. Remove the back trunk liner and you’ll see the corrugated metal that is open to the enclosure area.

[zeBugMan]

Hmmmm, so I may be able to just reuse the factory amp? That would be ideal. Here is a link to the sub installed. We're a bit over my head here, but I can definitely check the wiring later.

https://k.factoryoutletstore.com/det...-10cvt654.html

I'm not sure if the wattage of the sub is too high for the stock amp. Additionally, what I DO know is that there are four wires plugged into the sub with some 4-pin connector.

What I mean by "not drive" is, the sub will physically make sound, but not well. I guess it's clipping? It's not making GOOD noise for sure, especially at certain frequencies, and it seems to kind of "give up" and rattle.

[z3forlife]

The stock speaker was a dual voice coil hence the two pairs at the plug. You would only connect one pair to the speaker you now have. Match the polarity and that’s about as good as it gets driven by the stock amp. What year/model is this car. Two apps or one ? Finding input signal for the aftermarket amp would be the next problem if you wanted to go that route.

[zeBugMan]

Huh. It sure seems like the PO left the stock plug which has all four wires. Maybe that's causing the issue. Any idea which pair of wires to keep hooked in, and what to do with the other wires? Or, would either matching pair work? And what if I simply ran both pairs of wires in parallel, connecting both + wires to the single + on the speaker and both - to the - on the speaker?

The car is a 2000 M Roadster with one amp.

[delvec]

The Kicker Sub you have is definetly a single voice coil. The original wiring is set up for Dual voice coil. Z3forlife is correct, you will connect one set of wires to your sub to maintain the 4Ohm as was intended. The wiring in the Box (connected to the original HK Sub) is Red +/Black- or Green+/Gray-. Try the Red/Black first to you kicker and check your sound.

[zeBugMan]

Awesome, I'll do that and get back to you guys.

If that works, I'd be delighted, since maybe I won't have to install a second massive amp somewhere.

Out of curiousity, what do you mean by "maintain the 4 ohm as was intended"? Would trying to wire them in parallel change this?

[delvec]

The original HK Sub was a dual voice coil (DVC) rated at 2ohm. However, BMW's two sets of wires converts it to 4 Ohm. If you do a google search on Subwoofer Ohms wiring, you will see changing Ohms is typically done by wiring right at the speaker terminals. BMWs wiring is doing that already for you with there two sets of wires....All that said, It appears you have a single voice coil at 4 OHm therefore, you will only need one set of wires connected to it.

[z3forlife]

http://www.wedophones.com/Manuals/BM...g%20Manual.pdf
this link will show you the stock wiring for the whole car. Check the plug at the sub and see if terminal 1 is marked it’s usually moulded into the plastic. Use the wires from terminals 1 & 2 with #1 being positive. Make sure the other pair doesn’t short with a wire nut or tape.

[bob11x]

I am in the midst of speaker work also. Did connecting 1 pair of wires fix your problem?

I had ordered the subwoofer repair kit but alas the PO replaced it with something... haven't gotten that far down my list yet. My door cards needed extensive re-gluing. I have component set to replace the kick panel and the tweeters. For the life of me I cannot seem to find the page that showed how to install the tweeters. I think hot glue but I am hoping it was a better idea than that!

Awesome, I'll do that and get back to you guys.

If that works, I'd be delighted, since maybe I won't have to install a second massive amp somewhere.

Out of curiousity, what do you mean by "maintain the 4 ohm as was intended"? Would trying to wire them in parallel change this?

[z3forlife]

Save yourself some headache and replace the factory amp with a good 5 channel amp. You’ll love the difference. It’s a lot easier to match speakers to a aftermarket amp. There are harness adapters for the head end but the amp end you’ll have to make.

[bob11x]

Thanks for the advice. I probably will end up doing that.

Save yourself some headache and replace the factory amp with a good 5 channel amp. You’ll love the difference. It’s a lot easier to match speakers to a aftermarket amp. There are harness adapters for the head end but the amp end you’ll have to make.

[mobilenet]

Actually, if it’s the single alpine amp in the boot/trunk, there is an amp-end harness available through eBay if you don’t want to cut your wiring.

[rufusdog]

Do you have a link to the amp harness? I've searched but can't find it.

[mobilenet]

Do you have a link to the amp harness? I've searched but can't find it.

https://www.ebay.com.au/itm/BMW-Z4-H...-/164358033755


The person who makes this was able to adjust for the z3. (I’m not actually sure if the pinouts are at all different)

[rufusdog]

mobilenet - Thanks! Ordered. Can you describe how you used this in your audio system, and what equipment you installed as well? Might as well learn from someone who had a successful install.

[mobilenet]

mobilenet - Thanks! Ordered. Can you describe how you used this in your audio system, and what equipment you installed as well? Might as well learn from someone who had a successful install.

Worth mentioning it is for a z3 when you place the order. He has the electrical diagram I previously sent and his z4 wiring could be fine but just incase since it’s a pretty expensive purchase for what it is.

Sure. So I bought a clarion 5 channel class d amp. (Advice- would not do class d next time due to bad fm radio interference atleast for me)

The harness is wired in to the clarion amp and so it’s literally plug and play to swap between the the OEM amp and the new one.

In terms of speakers, be aware that the OEM amp has built in filters so your new amp needs to have low pass for the sub and high pass for the other 4 channels.

However, if your speakers are like mine, you actually have 2 small ones in each door, a 5.25 in each kick panel, a 4 inch behind each seat and a dual voice coil sub.

So 10 effective speakers and only 5 channels....

I have the sub powered by 1 channel (kind of obvious but you need to either change to a single VC speaker or wire appropriately for the OEM sub to power both VCs )

I have the rear amp channels going to the speakers behind the seats. Really wasted though because the speakers are useless and I could probably get as good an outcome with a 3 channel amp and not bother. I guess it’s nice to have the fader control do something, but I have it set so the rears are barely audible.

I have the front channels powering the 5.25 door speakers and also the smaller of the 2 door speakers. The other small speaker in the door is apparently a Mid, but I’ve decided it’s not super useful. To power both the door tweeter and the 5.25 from the 1 channel,I use a high pass capacitor at around 4kz to the tweeter. This can be easily wired in the trunk/boot between the relevant speaker wires in the harness. Lots of other ways to do this more professionally as component speaker sets do but a $2 capacitor does the job fine.

So one day, it would be awesome to get new speakers but it is really amazing what sound you can get out of the OEM ones with a proper amp. And at present, it takes me 15 seconds to unclip the harness, connect it back to the OEM amp and have a totally stock car with no wires cut , which I like.

[rufusdog]

Thanks. I'm looking at this amp. Waiting for the harness to arrive. https://www.crutchfield.com/p_500SA5....html?tp=35808

[mobilenet]

Thanks. I'm looking at this amp. Waiting for the harness to arrive. https://www.crutchfield.com/p_500SA5....html?tp=35808

It depends on the amp, but I have found class D interference quite a problem on the FM band using the standard head unit and antenna signal booster. The one you are looking at is class D, so unless there’s a return policy that lets you return if not happy, I’d look for a class AB amplifier personally.

If you are not planning to put in better rear speakers, you can probably find a cheap and powerful AB amplifier with just 3 channels that will save $$ and do a nice job. Just my thoughts.

[rufusdog]

Mobilenet (or anyone who used the ebay amp harness:

What are the A Diversity and K bus wires used for if used at all?

[jcjasso]

Save yourself some headache and replace the factory amp with a good 5 channel amp. You’ll love the difference. It’s a lot easier to match speakers to a aftermarket amp. There are harness adapters for the head end but the amp end you’ll have to make.

The PO replaced the head unit and I just checked on the subwoofer and it has a regular 2 channel speaker. Mine has the HK system. If I replace the amp as you suggest, I guess the current amps both need to be removed, then how do you use just the new one?

[z3forlife]

Do all the speakers work in the current setup? How is the aftermarket head connected to the harness ? Adapter or cut/splice ? There’s a person here that offers a adapter for the trunk harness plug that would be really handy for retro fits otherwise it’s cut & solder. I think his adapter may be only for the single amp systems though. Ideally you would have 3 pairs of rca cables from the front to the trunk but that’s a little work. The harness can provide front & rear L/R and if your handy with a soldering iron you can solder rca ends on the wires. Then you could use about any brand of speaker you want. The crossover for my front components is mounted in the stock amp location. The speaker color codes can be found at the wedophones site

[Wcumoron]

I made my own harness for the coupe without cutting anything. It converts the 12 pin and 26 pin and used factory wiring from head unit to adapter harness and from amp output harness to the factory wiring to speakers. Also went the harness route because laying in the rear of a coupe on a seat cushion with my feet in the air trying to solder connection sounded like a date with the chiropractor.

It all depends on how you want to approach the job.

If you have RCA cable ran back from the head unit that the PO installed, the inputs for the amp are already there. If you need additional RCA inputs for the amp or amps, you can always purchase Y adapters from Amazon to turn 1 input into 2. From there it is as simple as connecting to the outputs to the speakers. How those are connected depends on the specific amp that is already there.

I would also consider making adapter harnesses for coupes if there was any interest.

[jcjasso]

Do you guys think this subwoofer will work with the standard Harman Kardon set up? It's an 8" shallow mounting square subwoofer, given the dimensions of the current sub/mount I think it may work space wise.

Amazon.com: Kicker 46L7T82 Car Audio L7T Shallow Mount 8" Sub Square L7 Subwoofer L7T82 New