Subwoofer Earth Position In The Z4 Boot?

E

Exactmax

Active member
Hello,

I am trying to install my subwoofer into my boot of the Z4 and can't find anywhere to use for the earthing cable. I have tried the bracket over the battery but that is metal on plastic. I need a solid metel to metal connection - any ideas or advice would be great.


Many Thanks
 
Lol, what he said.

Although i use the mounting bolts for the plastic battery tray as i have 2 quite large earth cables.
 
It states in the manual that the earth cable should be connected to a metal to metal connection (i.e. the bodywork with the paint sanded away to bare metal, or a seatbelt bolt etc...). Would the negative on the battery really do the job?
 
The negative of the battery is the best place normally to connect it as it reduces interferance from things like the alternator and power steering.

Everything metal (well pretty much everything) in the car is earthed and connected to the batterys negative terminal in some way or another.
 
Connecting it to something metal on the body is basically just a round about way of connectiong it to the negative on the battery as thats where everything is earthed, basically your just cutting out the middle man by going straight back to the battery.
Just get a propper terminal and make a good connection, bobs your uncle etc...
 
Robb said:
Connecting it to something metal on the body is basically just a round about way of connectiong it to the negative on the battery as thats where everything is earthed, basically your just cutting out the middle man by going straight back to the battery.
Just get a propper terminal and make a good connection, bobs your uncle etc...
Click to expand...

+1

It's also usually avoided as you'd need to run a cable from the boot of the car, to the front of the car.. which can end in routing past another source of interference...
As our batts are in the "wrong" end, it's all gravy :P

(trying out some new phrases...lol)
 
Just installed my subwoofer and earthed it to the negative on the battery - worked a treat. Thanks for your help everyone :)
 
If you don't want to go direct to the battery and I personally don't as I like to keep such connections clean, then take a peak under the carpet. There's one earth point on the RHS iirc at the bottom of the wheel arch and another one on the top of the wheel arch on the NS. These are welded to the body and have bolt and nuts on so easy job.
 
EDIT: ive just seen your other post and it seems sk93 has answered all the questions! He also comments that the earth should not be connected directly to the battery and this was also my understanding but i can't remember the reason why :oops:

I may be telling you to suck eggs but here are a few tips if this is your first install…

Make sure the positive and negative cables are the same gauge (thickness) as I've seen some people use big cable on the positive and little on the negative. It’s all one circuit and both cables will carry the same current!

Personally I would ground the amp to the closest available grounding point – be that the car body or battery.

Do not run RCA cables next to power or the remote switching cables. These are what give you interference.

Make sure you have a fuse/circuit breaker as close to the battery as you can on the positive line (less that a foot realistically)

Set your amp to only run at ¾ power via the gain, an amp driven at full gain can cause clipping and screw your expensive speakers
 
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