[afsar]

In step 1-4 you seem to set highest undistorted high level for the headunit and amp volume - This ofcourse will be very loud when we are doing it in a residential street, how did you circumvent this? Also what is point in setting highest undistorted volume where they have to be matched to 30-40w each MS-8 channel, they aren't so powerful and all the amps are easily producing 70+ watt per channel. Aren't these steps redundant?

My amp is PDX-4.150, so 150 watt each channel set for 2v could fry the stock L7 speaker, atleast it will be too loud.

What is the idea here, is this understanding right?

1) Get the SPL level from all the speakers same, but in this case what is the use of having extra amplifier as you will have to reduce SPL level to minimum to match non-amped channels.
2) Do driver and passenger seat acoustic calibration after reducing volume a bit - Do you know what volume is best for calibration, I have read it at various threads that reduce your amp gain to 0 to do this calibration, that will undo the first step.

Excuse me for these noob questions.