As a broad overview of what's around for acoustic test and measurement, Mark described three general categories - single channel devices (like a sound level meter or RTA); dual channel systems (synched analysis channels allow any test signal); and single/multichannel with coherent clocking. Some details of operation and advantages/disadvantages of each were given.

Next, Mark spoke of measurement methods in more detail, including reviews of sampling theory, Fourier analysis, and filtering. One port devices included the sound level meter, oscilloscope, spectrum analyzer/RTA (Real Time Analyzer). Some time was spent reviewing windowing for data acquisition.

Two-port tests were then described, which use an input, device under test (DUT) and output to obtain a transfer function. After a review of mathematical modeling, Mark spoke about the direct form used by many test systems such as dual channel FFT and MLS, and matched filtering, including Richard Heyser's Time Domain Spectrometry (TDS).

During a break, door prizes were awarded:

• AEA mousepad (LA convention swag) - Bruce Winters
• RGB cables, courtesy Ed Gruse - Mark Rogers
• Whirlwind T shirt - David Lucavish
• Tote bag (LA swag) - Dave Rosgaard
• Tascam sticker + lanyard (LA swag) - Paul Colvin
• Voltlight (Fluke/RickR) - Ed Gruse
• Amprobe DMM - (Fluke/RR) - Rob Baum

Finally, some relationships to speaker testing were given, and there was a demo of a compression driver testing apparatus Mark developed, suitable for production line testing for problems like rub/buzz and distortion.