Establish your head unit's max level before clipping via DD1 or O-scope.
Get out your microphone and your RTA.
If the system includes a DSP, set the input and the output levels for all the channels at -12dB.
Set your crossovers and delays.
Have the target curve displayed on the screen. Play pink noise. Start with one speaker location and the sub--the left front or the right front.
Scale the target curve so that it appears at about the same level as the dips in your response.
Like this:
You may need to use your brain here. The idea in scaling the target curve is to consider the tools you have. We don't want to boost a bunch in the EQ.
Use the gain controls on the AMPLIFIERS to get as close to the target as you can.
Because we're using pink noise to do this, adjusting the levels at the amplifiers will set them according to a bunch of our objectives.
1. We'll turn the tweeter amp way down. This reduces noise. It also helps to prevent other failures in the system from causing the amplifier to send its full rated power to a speakers designed to handle far less.
2. It gets us PART of the way toward a good sounding car before we even start with the EQ.
3. It makes equalizing faster and easier.
Once you've done that for one channel, do the same thing for the other channel.
Then, using mono pink noise, play both channels with the sub and adjust the level of the sub UP to hit the target. If you're only using ONE input channel to the subwoofer, then you'll probably need to raise it by about 6dB.
Then, use the EQ.
One side first with the sub,
Then the other side.
Then, when they match, turn off the RTA and remove the mic.
Using a mono track of some kind, the 7 drum beats or the MUCH BETTER imaging tracks on the Audiofrog Tuning CD, adjust the channel levels in the DSP to center the image.
It may be easier to do this with input level than output level because the left input level will adjust the entire left channel. Same for the right channel. If you do this with the output channels, adjust the levels of ALL of the right or left front channels by the same amount to center the image.
Now, the car is tuned.
Except for one thing. It doesn't play very loudly.
But we left a WHOLE BUNCH of gain available in the DSP.
Turn up the input levels of the DSP until the system sounds loud enough for your customer but not so loud that there's a bunch of distortion or noise.
If adding gain to the DSP input isn't enough, add some to the output channels. Remember, the car is tuned, so when you add, add the same amount to each of the channels. .
Done. That's it.
Now, you can adjust for preference if necessary. If you feel like you need some additional EQ here and there and your DSP has an INPUT EQ, use it for this. If you feel like the center isn't in the center, go back and adjust the left or the right levels. DON'T USE DELAYS FOR THIS.