One of the more difficult facets of live sound is managing soundchecks. Most musicians will moan about how they don’t want to be bothered with a sound check, and in the next breath they’ll complain that their monitor mixes weren’t perfect at the start of the show.
As we’ve observed, advanced technology helps alleviate the pain of tedious setup and soundchecks. The ability to store (and easily transport) “snapshots” of a band’s live setup — including plug-in settings for EQ, dynamics, reverbs and delays — vastly simplifies setup for both front-of-house and monitors.
Engineers can take this “daily preproduction” up to another level through the virtual soundcheck. A virtual soundcheck replaces musicians with a multitrack recording, giving engineers the ability (at least in theory) to access the performance without having the performers present. The idea is to fool the console into thinking that there are mics on the other end of the wire instead of a multitrack recorder.
The first time I ever heard of such a thing was on a Rush tour during the early 1990s. If I recall correctly, Robert Scovill (Rush’s front-of-house engineer at that time) was using digital multitrack machines, either Alesis ADATs or Tascam DA-88s, to record the band’s performance. Recording an audio track from each microphone provided the ability to play back the recording into the mixing console the next day, using the tracks to fine tune the PA system, and adjust EQ or dynamics that were applied to a particular channel. The engineer gets the luxury of being able to tune (for example) the gate on a snare drum without making the drummer sit there and hit the drum repeatedly, plus you get a cloned replacement of the performer (as opposed to their tech), complete with their dynamics and feel.
Alas, the setup and patching of such a system based around an analog console was fairly complicated, and not for the faint of heart. The trick here was (and still is) to tap the signal and record it before any processing takes place. The feed for recording from an analog desk would typically come from an insert send, or a direct output — which might or might not be post-EQ or post-high-pass filter. If the signal was post-EQ, then the recorded track would contain that EQ and when played back into the console for the virtual soundcheck, you’d be double-processing the sound.
Fifteen years later, digital consoles are the norm, the benefits of which include a vast array of plug-in processing and the ability to record without a lot of hoo-hah. Since the audio signal has already been “digitized,” recording that stream of data can be as simple as making a single connection to a recorder equipped with the appropriate interface (MADI, for instance). At least one manufacturer — Innovason — offers a console (the Eclipse) that boasts a built-in 64-track recording system with a removable hard drive, so there is no need for any additional external connections or hardware to facilitate recording or playback. When the ability to record a show is made this easy (and cost effective), bands are inclined to do so, whether for commercial release, archiving purposes or as source material for the virtual soundcheck.
Despite the importance of soundcheck in terms of working out technical issues, getting musicians comfortable with their monitor mixes and giving the monitor and FOH engineers time to dial in their sounds, traditional soundchecks always have disadvantages compared to showtime: there is no audience providing feedback to the performers, the level of intensity is down from that of a show, the band may not be well-rested at soundcheck and some bands simply don’t like to take the time required for a thorough soundcheck. Also, sometimes scheduling does not permit time for a proper soundcheck. That’s where the multitrack recording comes into play.
If we have a recording of the previous night’s show, we have a pretty good representation of musicians playing their instruments in a high-intensity situation (and we all know that guitar players turn it up come showtime). This provides the “replacement source” for the musician, which enables the engineers to get an early jump on dialing in EQ or dynamics processor settings. It allows time for experimentation and valid comparison between different reverb or compression plug-ins. Valid because we can replay a particular passage of the recording while changing plug-ins and listening to the results, confident that the source is remaining the same. It gives monitor engineers the ability to accurately dial in cue mixes before the band arrives, avoiding the “me, me, me” confusion that often occurs when there are a lot of people on stage waiting to hear their monitors. It also allows a band to listen to themselves over the PA from front of house, making suggestions to the FOH engineer or evaluating the PA system.
Digital audio technology has the upper hand in this application because most digital mixing systems provide a means of tapping the signal for recording early in the chain — before processing has occurred.
Different manufacturers have different ways of dealing with this. The DiGiCo SD8 features a mode whereby the microphones are replaced with the recorded tracks upstream of the preamps, so even microphone gain levels can be adjusted using the tracks. Digidesign’s Venue taps the feed to Pro Tools before the high-pass filter and phase (polarity) reverse; upon playback, you can adjust input gain of the track as if it were the signal from the microphone. Digital consoles from other manufacturers such as Yamaha, Midas and Soundcraft feature similar routing abilities, enabling the recorded tracks to be “swapped” for the mic signals from the stage. The result is that an engineer can treat tracks almost as if they were mic signals from the stage.
A virtual soundcheck is not a perfect replacement for musicians, instruments and microphones, and the concept works best on tours where engineers are traveling with microphones and consoles. Mic selection and placement — and even the weather on any given day — have a profound effect on sound, as does the effect of the room on the sound of the instruments. But if you can get 90 percent of the way to your goal in 50 percent of the time, that’s a pretty good yield.
