at the moment, ive got it bolted to the bolt for the baby seat. is that a good ground. got it sounding alot better though. on my head-unit, i had some DZE turned on and was distorting the sound. my mate had the same head unit and got it all tuned up. thanks for the help guys.

ok after asking around, i think mabye ive wired the subs wrong. some mates are telling me its at an 8 ohm load, some say its at a 4 ohm and some say its at a 2 ohm load. want to run it at 2 ohms. anyone know how to wire it? ive got 2x 12" alpine type r's dual voice coil and its powered by a 1000W @ 2ohms alpine v12 monoblock amp.

Are the dual 4ohm or dual 2ohm?

Use this: http://www.the12volt.com/caraudio/woofe ... ations.asp

Gain works backwards (think of it as a "sensitivity" setting), at 0 the amp is trying it's hardest to amplify everything - hence the distortion. At the max value the amp is ignoring most of the signal.

Since you've got a digital setting, set it to be the same as the pre out voltage on the head unit. 2V is a common value, high end head units have 5 to 8 or more volts of pre-out.

There's many way of going about tuning, so that'd be why you got several different answers.

Settings the gains, is an important first step, get that right, or anything else you do will be an uphill battle.

I do it rather scientifically, one because I've got the right tools and know how, and two because with a high end system, there's a lot of amp channels to get right (I've got 8 individual speaks up front + a sub).

Requires:
- a CRO/oscilloscope
- a CD with appropriate sine tones on it. Preferably one tone in the mid band of each speaker than needs tuning
- a dB (sound) meter
- know the sensitivity values of each speaker (the dB/watt rating)

0. Set head unit to flat response, turn off 'bass boost' and all such sound enhancement options, they're CRAP, guaranteed. A properly tuned system will sound better without them. If there's any similar setting on you amp turn these off too. Again not needed.
1. Attach CRO to head unit RCA's, play 1KHz sine wave, crank head unit volume until distortion is visible (if you've a good head unit you'll go to the max with no problems), back off volume until it's gone, this is the maximum you should ever set the head unit. (to be thorough do the same with other frequency sine waves)
2. Set amps to a low sensitivity, Plug in RCAs
3. Start with the front speakers (if you've got separately amps split components midrange to begin with, then mid bass, then tweeters).
4. Play a sine wave frequency that fits in roughly the middle of the speaker your tuning.
5. Adjust gain up until distortion or worse clipping (sine wave has flat peaks) is seen on the speaker output wires. Back it off a bit. This is absolute loudest you can run (head unit is on max, and amp is up to just before distortion).
6. Move to next speakers, repeat 4-6 as needed.
7. Move to sub, repeat 4-6.
8. Now all amp channels are set to their max volume, for now on only move the gains down.
9. Using dB meter, test the speakers one at a time, find the quietest one. We'll have to tune down the rest to match.
10. tune down each of the other amp channels so the output volume matches the other channels.
10a. if you have the sensitivity values for each speaker, you can do this mathematically from the peak voltages displayed on the CRO.

The system levels are now set - and flat. You'll never have distortion and are very unlikely going to ever blow a speaker (over powering them is nowhere near as bad as under powering - clipping*).

A completely flat system, is exactly that, flat, possibly boring. Want some more bass?
Just keep in mind, if you want to adjust the output of a speaker up - turn the others down. This way you preserve your no distortion set up.

*clipping is a DC signal seen by the speaker, this rapidly heats up the voice coil, and because there's no cone movement, no cooling action is happening, result = fried coil. Over powering also causes extra heat, but the cone is still moving, so being cooled.