Sub and amp fitting

[Jake949]

Been given a sub with 2 12" speakers in it, and an amp to go with it. Just a little confused about fitting it to the car. I know I need a new head unit as mine doesn't have the pre outs, but how many pre outs do I need? And with the power cable, if it goes straight to the amp will it not constantly be powered on, meaning a flat battery ever time I go to start the car? I'm good with electrics, just never seen a sub wired up in person so have nothing to go off.
I'm guessing the 2 wires from each speaker go straight to the amp?
Then the pre outs from the head unit go to the amp.
Does the power lead then go from the battery straight to the amp? I would of thought there would be a remote switching cable to switch it on when the head unit is powered on?
Will be getting a head unit and wiring kit on Thursday.
Thanks guyss

[Danny2009]

If your buying a wiring kit it will come with everything

You need one set of pre outs on the head unit

The RCA leads go from the head unit to the amp
There will be a little wire as thin as speaker wire that goes from switched live on the head unit to the amp the instructions you get with the head unit will tell you what wire this is just splice into it

You also need a earth good point is the bracket that bolts the seats into the boot it's at the back of the boot in the corner as your stood at te back of the car, scrape what paint off you can to get a good contact

Then the power lead comes direct from the battery to a fuse that's in the kit, then through the car into the amp and as you say speaker wire from the subs to the amp

If its all wired correctly at te head unit the amp should turn off when the head unit does so no flat battery

Hope this helps

[Jake949]

That makes sense now, so there will be 2 rca plugs?

[Danny2009]

Yea 1 set a red one and a white one they always come in pairs will look just like they do on the amp but on the cd player

[Jake949]

So when I'm looking at head units on halfords because loads are reduced in price, it says pre outs-1, do you think that's 1 pair yeah?

[Willo]

Yeah that's one pair mate it'll be one red and one white

[Jake949]

So is one pair enough for one amp I'm guessing?
I'm guessing the switched live wore will go to the remote port on the amp too?

[Danny2009]

Yea that's correct mate, you only need one pre out for 1 amp

[Willo]

Yeah it's usually a blue wire the headunit will probably have a wire labeled remote so just splice that run down the car and connect to the remote part of the amp dead easy just run your RCA cables the oppersite side to your power cable else you will get interference

[Eeyore]

This should help:


Read These:
The audio big 3 helps the alternator by providing better earths. Stops headlights flickering and dimming when the amp is drawing a lot of current.
http://306oc.co.uk/forum/thread-382.html
http://306oc.co.uk/forum/thread-2830.html

And sound deadening is always a good idea!
http://306oc.co.uk/forum/thread-227.html

I dont know why there isnt a guide to fitting a sub and amp. ill have to write one at some point!

[Jake949]

thanks for that diagram mate.
got everything i need now, just theres no hole in the fire wall to feed the power cable through into the car. dont really want to drill if i can help it.
any ideas?

[Eeyore]

yeh. there is a grommet to the top right of the brake master cylinder in the engine bay. It may be covered on foam from the inside. To get to it on the inside easily youll have to remove steering wheel coweling and the speedo.

You can see the clear turbo coming through the grommet behind the speedo here...
http://i1184.photobucket.com/albums/z327...142220.jpg

and this guide tells you everything how to remove speedo and coweling...
http://306oc.co.uk/forum/thread-9781.html

Either that or drill through the passenger footwell to one side of the big rubber tube\grommet down there. Somebody will probably turn up in a bit and say you can put it under your car but i dont like that! By putting it through the speedo grommet youre using alot more of the cable length to route it to one side of the car and back again. in all honesty drilling the passenger floor is my preferd option but the whole for the speedo was already there so i thought why not!