Replacing the footwell speakers and door tweeters - a guide

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Joined: Thu 24 Mar, 2011 17:58
Posts: 475

  Z3 roadster 2.8
Location: Derby

Replacing the footwell speakers and door tweeters - a guide

Post by XVar » Sun 24 Apr, 2011 23:06

Today I replaced the standard footwell speakers and door tweeters with new component speakers, and I thought I'd take pictures along the way to save other people going into this completely blind as I did. I'm really pleased with the result, the new speakers sound -much- better than the standard ones, for not much time and money outlay.

This is a guide on how to upgrade the standard front speakers on a pre-facelift Z3. You cannot fit any larger without having to cut larger holes in the bodywork.

This guide is NOT for you if you..

Have the HK sound system upgrade.
Have the stock headunit.
Have a facelift Z3 - it may be exactly the same but until someone confirms continue at your own risk if you have a facelift model.
Have the amp on the back of the left footwell speaker - although most parts of the guide will be the same I'm not sure how different the wiring will be.
You want to amp your speakers - this would involve a lot more wiring as you'd most likely have to put the amp in the boot.
Don't know how to use a soldering iron.
Aren't comfortable with removing a lot of trim (all of the footwell trim and door cards).
Don't want awesome sounding speakers and enjoy the rubbish stock ones.

This guide IS for you if you..

Want awesome sounding speakers.
Have a headunit with a minimum of 35w RMS output per channel (varies depending on your speakers, my headunit is 4x50w RMS).
Have 2-3 hours spare.

Tools required

Philips screwdriver
Wire cutters
Soldering Iron + Solder
Shrink wrap (can be substituted with electrical tape)
Lighter (for shrink wrap)
T10 and T20 torx drivers
8mm socket wrench
Male/female spade connectors (optional - not used in this guide but would be a good idea)
Volt meter

The aim of this guide is to repace the 5.25" woofer in the footwell, and the 1" tweeter in the door with better speakers, in my case a set of Edge ED305 components (£39.99 from Halfrauds). The existing wiring from the headunit to the tweeter will be cut to enable the installation of the crossover for the new speakers.

What I'm installing in this guide:

1) Remove the footwell trim, first remove the part under the steering wheel - it's held on by 3 or 4 screws near the front and 1 on the side (by the door hinge). Next remove the bonnet release handle, which is held on with a single screw, and remove the side panel which covers the speaker. Remember how this panel comes off, to save yourself 15 minutes of swearing when trying to put it back on the wrong way.

2) Unbolt the existing woofer using an 8mm socket wrench, keep the bolts as you need them to mount the new speaker. Disconnect the spade terminals on the speaker and remove it.

3) Cut the wire pair going into the door, as close to the back of the footwell as possible, leaving about an inch so you can insulate it. This is the wire which goes to the tweeter, which will be wired into the crossover.

4) Remove the door card, an excellent guide by myredzed is available HERE.

5) Disconnect the tweeter plug. The lump in the wire is the crossover capacitor for the standard tweeter, which is why there is no separate crossover box. It prevents low frequencies from blowing the tweeter.

6) Remove the tweeter housing, it's held on by a single screw.

7) Remove the grill from the tweeter housing, it's held on by about 8 folded over flaps. A flat bladed screwdriver will help to lift them up.

8) Remove the tweeter from the housing using a Torx T10 driver and add it to your pile of obselete speakers.

9) Insert your new tweeter into the tweeter housing. Mine just about fitted, you could cut the housing if necessary. Make sure it doesn't stick out any more than in the below photo or you won't get the grill back on.

10) Replace the grill and push the flaps back down. As you can see I need new grills as they've gone rusty due to past leaks. Turns out black marker pen just makes them look like they've got a disease.

11) Cut the yellow connector off as close to the connector as possible. It has a brown and a black wire, on mine the brown one goes to the brown wire in the footwell, and the black one goes to the red wire in the footwell. I've wired mine up so that in the footwell, brown is negative and red is positive. This means soldering black in the door to positive on the tweeter, and brown in the door to negative on the tweeter. This is where a volt meter comes in handy as you can use the continuity test mode (the one that beeps when you close a circuit between the probes) to find out which wire inside correspondes to which wire in the door. Yours may be completely different colours from mine but with a volt meter you can figure it out either way.

12) Solder the tweeter to the black and brown wire in the door - you may wish to use spade connectors to enable easy disconnection of the speakers in the future when removing door cards. This is probably something that I'll do in the future. If you make a bare solder connection either put a length of shrink wrap over the wire before soldering, or wrap it up with electrical tape after. If soldering, make sure that the tweeter wire is through the hole in the door card plastic before soldering.

13) Solder the input of the crossover to the remaining wire coming from the headunit (the one we didn't cut earlier). If soldering, you'll need to cut the spade connectors off (this wire was previously connected to the standard speaker). Again, you may wish to solder spade connectors instead of a direct join.

14) Solder the tweeter connection of the crossover to the brown/red wires that go to the door. If you did it as above, red should be positive and brown should be negative.

15) Do not cut the spade connectors off the woofer connector on the crossover, these will be plugged into the new speaker.

16) Plug the woofer output of the crossover into the new speaker, and fit the new speaker in the hole the old one was removed from, using the original 8mm hex bolts. There is a gap at the top of the speaker hole for wires to go through.

17) Insulate the head unit end of the tweeter wire which was cut in step 3, either using shrink wrap or electrical tape.

18) Wedge the crossover at the back of the footwell out of the way.

19) If you have the phone kit attached and don't use it, now would be a good time to remove it while the trim is off. I'm not sure if it has a detrimental effect on sound quality, but it's just unnecessary clutter if it's not being used anyway. It's behind the head unit, accessed via the access panel by the drivers left knee (held on with two screws).

20) Replace the side panel.

21) Replace the top panel.

22) Job done.

23) Repeat steps 1-21 for the passenger side, the procedure is identical apart from the footwell trim is slightly different.

That's it! Thanks for reading and if you've got any questions feel free to ask away.

Joined: Wed 01 Feb, 2012 18:06
Posts: 124

  Z4 coupe 3.0si
Location: Bath

Re: Replacing the footwell speakers and door tweeters - a gu

Post by Sp1key » Sun 29 Jul, 2012 11:36


Just changed my speakers and tweeters using this guide, this was very helpful thanks for posting this on the forum




User avatar
Joined: Thu 24 Mar, 2011 17:58
Posts: 475

  Z3 roadster 2.8
Location: Derby

Re: Replacing the footwell speakers and door tweeters - a gu

Post by XVar » Sun 29 Jul, 2012 12:37

Awesome, glad you found it useful :)
1997 2.8 Z3 | Gallery Thread


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