Earthing an amp in the boot.

[mhibbins]

I've just spent today putting in some infinity 6x9 speakers in my s3 and I think an amp would help after all (the head unit is a bit stressed). Has anyone installed an amp in the boot of an s3? If so, where did you earth it? The only thing I can think of it to take the earth lead through the floor to the chassis but don't fancy drilling the hole. Is there a better way?

Ta,

--
Mark

[LeeBee]

I have 2 amps and a DSP unit in the boot, all the cables run up and over the wheelarch in the boot and run down inside the sills (I use one sill for power and the other for audio) these come out in the footwells and go into the engine bay and behind the dash etc, you may struggle though as your footwells are probably enclosed being an S3?.I run both the positive and the negative back to the battery using gold plated battery clamps.Hope this helps?

Cheers

Leebee

[mhibbins]

Is that safe? I'm quite happy to run a cable back to where the main loom goes through the bulkhead along under the transmission tunnel cover (where I'm running the speaker cable) but I was told that I need to earth as close to the amp as possible (presumably closer than 3m).

Thanks,

--
Mark

[Paul V]

When running the live, you should use a fuse within 12” of the battery you’ll then be ok, your correct in saying the earth is best closest to the amp, I’ve not looked into it yet but may if I get a sub, I’d look for something that bolts to the chassis then fit a ring terminal to it, obviously it should be something non important, you could also add another nut to the end of any bolt though the chassis to give you the earth.

[LeeBee]

The positive is fused about 1.5 feet away from the battery, both cables are large gauge because they feed into distribution blocks and then the smaller cables run from these, all conections are soldered into gold plated connectors to ensure good conductivity.This is sort of temporary anyway because I will be relocating the battery to the boot in the near future (I am also going to completely redesign and make a new wiring loom for the entire car so anything could happen!).I will take a few pictures if anyone wants a look?

Cheers

LeeBee

[Paul V]

I’d like a look

I was led to believe that crimped or screwed connections are best for automotive use, something to do with the vibrations causing connections to break when using solder, I sometimes crimped then soldered as well.

[LeeBee]

The wires are soldered into the crimps then screwed into the amp terminals etc, never had a problem with this, Nitron shock absorbers and springs keep vibrations smooth

Cheers

LeeBee

[johno]

How do you know that ? You never drive the thing !

[PeterC]

The nearest earthing point to the boot is on the n/s chassis upright. Remove the nearside rear wheel and you should see it.

This is the earthing point for the rear lights, so there must be a cable exiting from the boot at some point and a hole must already exist.

If you run a sound system as loud as this, how do you hear the engine - this is half the fun of driving a TVR.

[mhibbins]

Thanks for the advice. In the end I just plugged the 6x9 infinities straight into the new pioneer with some beefy cable and it sounds fine and is quite loud enough. Now to put the amp and the old alpine in the land rover

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Mark

[M@H]

I'd like to know how you run a loud sound system in a small car too (I mean cockpit size).. having permanently damamged one of my ears with two 12" subs and 2 amps in my beetle, how do you get any distance between you and the speakers...??

Cheers,
M@

[LeeBee]

quote:
How do you know that ? You never drive the thing !

Nice one Johno, how are your wheel bearings?

Cheers

LeeBee

[johno]

Changed the one over Xmas in 1 hour !!!

Thats pretty good going.

I'm sure you're still on the first wheel bearings your car came with !

Of course I'd like to be in your position !

How are the Nitrons then ? I'm considering changing the whole rear end for newer S3 arms and changing all the dampers for Nitrons. I'm not happy with the replacement arms I have at the rear and cannot get a satisfactory camber for either rear wheel. Also as I am doing on average 15000 + miles a year it's worth me investing in the Nitrons...

[LeeBee]

Nitrons are very good seeing as they are still in their boxes here in the office! (waiting for Kirkey to make some coil over covers so the distributers actually have some in stock!).The wheel bearings have been changed but only coz it's got the bigger taper roller version due to the rear discs.I am getting it ready though

Cheers

LeeBee