Last summer, DiGiCo announced the Quantum 7, an expansion engine designed for its flagship SD7 mixing console. The “standard” SD7 employs a CPU capable of processing 256 audio paths at 48 or 96 kHz (or 128 paths at 192 kHz). The Quantum SD7 employs Super FPGA (Field Programmable Gate Array) devices that enable the console to process more than 650 channels of audio at 96 kHz. Let’s look at some of the stats: 256 input channels, 688 dynamic EQs, 128 Aux/Subgroup buses, 688 multiband compressors, 48 digital effects, 48×48 processing matrix, 48 graphic EQs. It borders on frightening. Owners of existing SD7 consoles can have the Quantum engine retrofitted into their desks.
The Joy of FPGAs
Specifications are all well and good, but when I saw a demo of the SD7 Quantum at NAMM a few weeks ago I was completely blown away, and not because of sheer numbers. I was blown away by some of the ways that DiGiCo engineers have applied that power. They’ve just flipped over the lunch cart.
Let’s suppose you’re a monitor engineer mixing IEMs for a major tour (or even a not-so-major tour). You’ve got five band members, all having different models of earpieces, different hearing characteristics and different tastes in audio. Maybe one of them wants tons of high-end on the kick (like, that never happens). The problem is that — when you EQ the kick drum channel to make that person happy — all the other band members will hear the same EQ, and they may not like it. Depending upon the console, you might be able to tap some of the aux sends pre- or post-EQ, but that only means that some of the folks get no EQ on the kick drum (wow, how spoiled we’ve become).
One way to solve this problem is to mult the kick drum mic (or mics) to a separate channel, use one of the channels for the band member who wants all that top end, and use a different channel with a “normal” EQ to feed the mixes for the rest of the musicians. We’ve all done that, sometimes in the analog domain (a pain in the arse) and often in the digital domain (less of a pain in the arse). It gives you another channel to manage. Now you’ll need to keep track of which kick drum channel has the whack EQ, and who gets that version in their monitors versus who gets the “normal” EQ version of the kick drum.
The Node Knows
DiGiCo’s Quantum engine solves this issue by introducing their patented concept of Nodal Processing, which allows you to assign an EQ/dynamics processor into any node of the aux section of the desk (up to 256 times). Read another way: you can drop an EQ/dynamics block on any send of any channel. Reread that carefully: any send, not just the send master. Aux node send points can be pre-fader, post-fader, pre-mute, pre-EQ/dynamics, mid-EQ/dynamics or pre-processing.
Remember that musician who wants the top end on the kick drum? Let’s say the monitor mix for that person is aux send 1.
Nodal Processing allows you to patch a processor onto aux 1 only for the kick drum channel. The EQ and dynamics for the kick send to aux 1 are completely independent from the EQ and dynamics for the kick send to the other aux sends, and are completely independent from the EQ and dynamics for the kick channel path to the L/R mix. Other channels contributing to aux 1 are not processed with these EQ/dynamics as they might be if you processed the aux 1 send master. In fact, you could drop a processor on each aux send from the kick channel, and provide every musician with different EQ and dynamics settings in their monitor mix. I guess this also solves the issue of drummers who don’t want to hear gates on their drums versus the musicians who want the toms gated.
A similar concept could be applied for different zones in a venue, where perhaps you need more bottom-end just on that kick channel for the lobby mix (where the subs are not contributing).
Enter the “True Solo”
If you’re paying attention, you might wonder “How do I cue up the mix with the whack kick drum sound?” DiGiCo came up with a solution for that and it’s called True Solo. True Solo lets engineers copy any internal processing from an output bus to the Solo bus, so they can hear what the musician is hearing. If you want to hear the IEM mix with the whack kick sound, you can do so.
This is a completely new level of creativity, DSP manipulation, and audio insanity. Think about it: you can now have separate kick and snare EQ for every musician. Maybe we shouldn’t tell anyone about it. Maybe we should because it’s job security.
DiGiCo has patented Nodal Processing, but this is a game-changer. I expect that in the future this type of DSP will become commonplace. Remember when a digital console with four built-in effects processors was a big deal? My prediction? Eventually, this type of processing will be as routine as those four onboard effects. It’s just too powerful a feature not to be.
Steve “Woody” La Cerra is the tour manager and Front of House engineer for Blue Öyster Cult. (And no, DiGiCo did not offer to buy him dinner in exchange for this article.)
