This month, columnist Steve La Cerra looks at music he uses to check out sound systems, with a lot of well-engineered cuts that are commonly used by FOH and system engineers on the road. (See “On the Digital Edge,” page 26.) These can provide valuable insights into the character of the room/P.A. interaction, but it’s important to consider that voicing a venue is hardly the same as listening in a stereo store. In the latter, where you’re only 10 feet from the speakers, the room’s effect is minimal, at least when compared to listening to a P.A. hang in a plaster-walled art deco theater.
Albums are rarely recorded “dry” and hearing the reverb from the music combined with the acoustics of a live room can create confusion, especially for the novice engineer. However, a familiar recording can at least provide a starting point with a few clues about the nature of the space, and the right song can also highlight conditions like room slap or “dead” zones where the coverage doesn’t reach. As an alternative, playing pink noise or frequency sweeps can be quite revealing, while a track of dry recorded vocal narration will give a quick indication of intelligibility.
One favorite of mine (although long out of print) is Denon’s 1988 Anechoic Orchestral Music Recording, a CD of classical music that was close-miked with the players performing inside a makeshift anechoic chamber on a recording stage. Acoustically, “dry” is the word here, so a playback in a performance space provides a true feel for the room’s reverberation characteristics.
System tests need not be complex. A simple indicator is playing “walk” music before the show, which gives some reassurance that the system is functioning (or at least the generator has fuel) before the band’s first downbeat.
So what’s in your (CD) wallet?
Got a comment? Send George an email to george@fohonline.com
