Well, I ran a 20 - 20 kHz sweep test track on the spectro visuals, and it showed a pretty sharp peak across the whole display. I then used CoolEdit to create a track which stepped at known frequencies up the spectrum and marked them on a paper overlay. They were pretty good: if only we could create a background scale image (a la AnnaVU) to allow us to annotate the spectrum diagram so it could be used for reasonable calibration purposes. Whaddaya think, Toby?