"Stewart Pinkerton" wrote in message
...

That's true, but unless you have access to good SPL measuring gear,
you may have some difficulty knowing where 'flat' is unless everything
is matched.

You don't need to be able to measure the SPL, just the signal generated by a
microphone. Take some frequency within the range of the bass and mid-range
speaker, feed a signal to the bass speaker, and measure the microphone
output. Now feed the frequency to the mid-range, and adjust its level until
the microphone is generating the same ouput.

Repeat for the mid-range and HF speakers.

You don't even need a calibrated microphone.

Tim