Confirm wiring subwoofer install

[ZDNB]

Hi All

Recently purchased a couple of Z4 official sub woofers and brackets from a breakers. I have a basic HiFi with SatNav so I got everything I needed, including an amp to drive them, and wired them up today and works very nicely!

Got a question though I need a little help with before I make my connections final. I have hooked into the rear speaker wires (yes they do seem to give a full signal ) for my RCA converter and I wanted to make sure I had the positive and negative the right way around.

My cable colors on the left speaker are yellow/grey & yellow/purple and on the right Blue/Grey & Blue/Purple. how do I work out which is +/-?

Also on the official Z4 Subs same question, I see no obvious markings on the sub to identify which is the +/-. Any pointers? Pictures below (part code 65139143268)

Finally, anyone know best ignition switched cable to use in rear, or fuse box?

 

[Darkangelv2]

With regards to your remote wire (switched live equivalent) I used the rear aerial amplifier. It’s a white wire located behind the passenger tail light cover tucked up on the inside of the wing. It’s a genuine remote wire sent from the head unit

You’ll find which colour drives what by searching “bmw z4 stereo wire colour” on google. There’s a full list circulating various forums - I think it was an image when I was looking.

 

[ZDNB]

Nice one on the aerial tip, will check that out tomorrow, saves running to fuse box!

Also found the wire colors after your google wording tip, will put here in case its useful for someone else

Left Rear Positive = Yellow/Purple
Left Rear Negative = Yellow/Grey
Right Rear Positive = Blue/Purple
Right Rear Negative = Blue/Grey

Will also use this trick to determine +/- on sub itself. https://www.youtube.com/watch?v=XECdxm3udlI

 

[Z4C_er]

including an amp to drive them, and wired them up today and works very nicely!

Hi, what amp did you get?

 

[ZDNB]

With regards to your remote wire (switched live equivalent) I used the rear aerial amplifier. It’s a white wire located behind the passenger tail light cover tucked up on the inside of the wing. It’s a genuine remote wire sent from the head unit

Worked perfectly thanks so much!

Hi, what amp did you get?

Its an old one I had from my previous sub setup, been sat around for ages. Alpine MRP-T220, Will see if it holds up....

 

[Darkangelv2]

With regards to your remote wire (switched live equivalent) I used the rear aerial amplifier. It’s a white wire located behind the passenger tail light cover tucked up on the inside of the wing. It’s a genuine remote wire sent from the head unit

Worked perfectly thanks so much!

Hi, what amp did you get?

Its an old one I had from my previous sub setup, been sat around for ages. Alpine MRP-T220, Will see if it holds up....

No problem - sounds like the exact type of install i did!

15 year old 2 channel Vibe Blackbox Amp
12 year old Elemental Designs 6" Sub

Still works a treat and it doesn't need to break a sweat to add depth to the small cabin. I coupled it with a second hand set of Hertz 3-Way speakers in the front and it's transformed the underwhelming OEM (Basic) setup very nicely indeed

 

[Z4C_er]

Thanks both. Currently looking at this type of setup or an active subby that can slide in behind the seat. There are some posts on here, but has anyone recommend an underseat jobbie?

 

[MDUBZ]

I'm going to have a crack at that very thing this weekend.

I've ordered an under seat unit ( which I know wont fit under the seat) that I'll mount it in the boot; if the sound doesn't penetrate to the cabin then I'll find an alternative mounting position probably behind the passenger seat.

I took this route because, to be honest, I dont know what I'm doing, some of the other threads are full of technical jargon which I've understood some of, but which quite frankly, nearly scared me off ( fair play if you understand it all).

I appreciate the performance wont be as high as going down a separates route but I wanted a discreet easy to fit solution and I'm very much in the keep it simple stupid camp. I'm no audiophile so I'm not looking for the perfect set up, but the crap sound system has annoyed me for the last 5 years of ownership and having replaced the rear speakers because the oem ones had blown over the winter , ( got the crappy 6 speaker system); it sounds far better than it ever has but it is now seriously lacking in the lower ranges. I bought a pioneer unit ( wx130DA) its compact, has good reviews and for about £120 from amazon (as new but damaged packaging) I thought it was worth a punt

The Plan:
I'll tap in to the rear speakers, connect to the remote wire (either the white from the aerial booster or apparently there is a purple and white cable under the carpet that can also be used?) and connect to the battery for earth and positive.

Sounds terribly straight forward so it is bound to go wrong, I'll document: it will either hopefully be of use to someone or give us all a good laugh.

 

[Z4C_er]

I'm going to have a crack at that very thing this weekend.
Sounds terribly straight forward so it is bound to go wrong, I'll document: it will either hopefully be of use to someone or give us all a good laugh.

Hey, thanks, that's pretty much where I'm heading too! How easy was it to change the rear speakers?

 

[MDUBZ]

I'm going to have a crack at that very thing this weekend.
Sounds terribly straight forward so it is bound to go wrong, I'll document: it will either hopefully be of use to someone or give us all a good laugh.

Hey, thanks, that's pretty much where I'm heading too! How easy was it to change the rear speakers?

It wasn’t hard, if you can undo a screw, but it’s a lengthy process because you need to remove a lot Of the interior to get at them (3-4hr job). You need to get speakers with the right resistance as BMW’s use 2ohms and the speakers have a 3 point fixing rather than he standard 4 which narrows the options available.There isn’t a lot of space so speakers with integrated tweeters are a squeeze (ask me how I know 8) )

 

[MDUBZ]

I have a pdf with the steps if you need it. But it won’t let me upload it here but you can download here: https://gofile.io/d/AHUbHD

 

[Z4C_er]

I have a pdf with the steps if you need it. But it won’t let me upload it here but you can download here: https://gofile.io/d/AHUbHD

Thanks. I'm wrapping all the ally bits (incl. the centre console) so already at the point of no return. Got most of the trim out except for the outer panels over the speakers. It's been a frustrating time waiting for the stock of my wrap to arrive (wholesaler is waiting on the wrap for 4 weeks now) so twiddling my thumbs wondering what else I can do....
I liked the idea of the underseat woofer, but today realised that under or behind the driver's seat won't work. So interested in locating the unit in the trunk, like you. An alternative may be the little Alpine jobbie:
https://www.caraudiocentre.co.uk/product_m-alpine-car-audio-systems-swe-815_p-27715.htm
But I'll hold off to see how you go, as it will be heaps neater. All the best!

 

[ZDNB]

think the most painful part of this mod was having to go to Sytner and asking for 12 mounting screws and bolts that are specific to the brackets of the official subs, £38 ... also just found the speaker grill covers on ebay for another £80 to finish it off.

Whilst it isnt face melting bass, it adds a depth that wasn't there before, I think I will be adding the extra door speaker fed from the tweeters next!

 

[Darkangelv2]

think the most painful part of this mod was having to go to Sytner and asking for 12 mounting screws and bolts that are specific to the brackets of the official subs, £38 ... also just found the speaker grill covers on ebay for another £80 to finish it off.

Whilst it isnt face melting bass, it adds a depth that wasn't there before, I think I will be adding the extra door speaker fed from the tweeters next!

Yeah - i couldn't face all that! I did manage to pick up most of those parts from breakers but ultimately would replace the Sub bracket with MDF and nuts with bolts if to save that money! You could then cut away at the standard cubby hole plastic to leave the fascia and clips only then cover in speaker fabric.

 

[Z4C_er]

I'm going to have a crack at that very thing this weekend.
Sounds terribly straight forward so it is bound to go wrong, I'll document: it will either hopefully be of use to someone or give us all a good laugh.

Good luck with the project this weekend. Looking forward to seeing the results!

 

[MDUBZ]

all completed, the hardest part (was a little fiddly in a non Ralph Harris type of way) was cutting the ends of an rca cable off and crimping 4 connecters on the end of the wires to splice into the speaker cable (cheap cable and the wires are very thin). The sound is far richer than before: it isn't eyeball shaking, chest vibrating levels of bass, but even with the roof down at 70+ :evil: (I went out for about 45 mins as i was worried about pissing off the neighbours) and the sound is much much fuller.

I tested it with everything from Little Richard to Queen to Mark System's Optix for some grimey drum n bass. Wish i'd done it years ago. Many thanks to @Darkangelv2 and @ZDNB as it was the kick up the arse needed to give it a go. I'll do some tweaking with it to get the sound as i want, but on the whole very happy. Install took about an hour: i'll tidy up all the wiring later.

Live and earth


remote to aerial booster (white) near the rear light (tilt head to the right for correct orientation)


Left speaker


right speaker


fixed in place using sticky back velcro for now until i finish the fitting (you'll need to stand on your head for the correct orientation)

 

[Z4C_er]

I tested it with everything from Little Richard to Queen to Mark System's Optix for some grimey drum n bass. Wish i'd down it years ago. Many thanks for the OP for giving me the kick up the arse to give it a go. I'll do some tweaking with it to get the sound as i want, but on the whole very happy. Install took about an hour: i'll tidy up all the wiring later.

Thanks for posting the story and pics, OP! So, it sounds like a successful venture. You said you were happy, but do you think you'd be happier if it were behind the seat, or is it enough? I'll probably do the same as you , but try and mount it against the back wall.
Thanks again!

 

[MDUBZ]

Probably better in the cabin, but tbh I wasn`t after perfection, which you’ll never get in a small convertible anyway due to lack of space. I’m quite happy, it fills the hole in the range that was clearly there.

 

[Z4C_er]

Hi, I just went out to look at possible locations for mounting my unit and discovered that it seems that there would be enough space between the carpet and the back wall. I measured around 90mm in the space. This seems to be only a coupe thing, as your carpet seems to have a step.

 

[MDUBZ]

that will work pretty well and I suspect you'll get a better sound in the coupe. I had the roof down yesterday so there was a bit more of a barrier between me and the speaker - It will probably sound better with the roof up as there is just a plastic shelf in the way, the sound will be more contained in the cabin and there will be less wind noise.