Andrew, I know you were kidding with me about the SPL meter "gadget", but I certainly have had the Radio Shack digital model(far superior in different measurement modes available)for years and use it often, but not for speaker calibration anymore. I use it to verify that the listening levels I use at various times for music are safe and that the amount of power that my receivers can supply is in fact more than needed, even on brief peaks.
An interesting task I've given it a couple times is when I've taken it to a concert with me to test for orchestral sound levels. I had to reassure some of the other patrons that it wasn't a bomb. When I explained what I was doing they probably still thought that I was a nut, but not a dangerous one.
