Not sure whether i need a whole tutorial on this but i have been getting a whole lot of messages about fault finding and problems so here is some info to help

- Start from the problem end and work backwards working with only one thing at a time.

Example
Say for example you have a buzz comming from your sub.

- Start with the sub itself, dissconnect the sub and try another one. If the problem stops then the sub was the problem, if not proceed further
- Check the amp, you will need to check all inputs and outputs to it. Check the speaker wire first. It must be connected solidly and with no stray wires touching the other terminal or the chasis of the amp.
- Then check the crossovers and gain settings. There may be sticky pots which can need a bit of electrical contact cleaner, adjust them up and down while the system is running and see there is any noise through the system
- Then check power and earth connections. A lot of problems are caused by poor earth connections. Ensure it is solidly connected to the chasis and the paint is stripped back. You may need to try a couple of earth points to get a good one.
- Ensure power connection is sufficient and correct gauge power cable is being utilized. If the cable is too small then there is voltage drop and most amps will only accept as low as 10.5v and then trip out. If they cannot get sufficient power then they can go into clipping
- Check RCA connections. This is a very common problem, loose leads, poor quality leads, bent plugs with pressure on them, or RCA's running next to power canle will all introduce noise into the system
- If you have another amp in the system try swapping the RCA and speaker connections to run the sub from the other amp. If the problem goes away then you have narrowed it down to the amp.
- If not then check the RCA's at the headunit end. Run another lead outside the car from the headunit around to the amp
- Try another source unit. Even a discman with an adaptor plug straight into the amp will work. Have the gain set a minimum when doing this


This works for any speakers or subs. Simply wrk back from the problem one thing at a time. Never change more than one aspect at a time otherwise you will not narrow down the problem.