Integrating Mixing & Signal Processing

Do you fully appreciate your mixer's capabilities when it comes to using effects and signal processors? Craig Anderton reminds you of a few tricks your desk might have up its sleeve.

Our recorders and effects are turning increasingly digital, but when it comes to hooking all this gear together, it's often still an analogue mixer that does the job. The flexibility, number of patch points, and hands‑on control available from analogue mixers remain appealing, as does the cost. However, in many ways these venerable boxes are still under‑utilised, particularly when it comes to using effects. Here's a selection of tips designed to better integrate mixing and signal processing.

Keep A Straight Sound Straight

Although mixer input‑channel effects loops are convenient for patching in effects, some processors alter the straight sound. Fortunately, you can preserve the integrity of the dry signal yet still add the desired effect; the patching option depends on your mixer setup.

In any case, the first thing you need to do is get a send from the input strip signal. There are three ways to do this:

• If your mixer has separate input‑strip loop send and receive jacks, patch into the send. This should not break the normalled channel connection that allows the dry signal to pass through to the stereo mixdown buss.

In many ways, mixers are still under‑utilised, particularly when it comes to using effects.

• Newer mixers often use a TRS (tip/ring/sleeve) stereo jack to handle the effects send/return. Plugging a lead halfway into the jack (so that the plug tip contacts the jack ring) should provide a send without breaking the normalled connection.
• If you don't have loop jacks, use an aux buss to provide a send from the channel.

Patch the send into the processor, which should be set for effected sound only (no dry signal). Then bring the effects output back to a separate channel and mix in the desired effects blend at the mixer (dry sound on the original channel, processed signal on the additional channel). As a bonus, using this approach lets you modify the effects signal with panning, reverb, aux sends to other effects, and all the other input channel options.

Better Reverb Pre‑Delay

For more control over your reverb sound, patch a delay line between the effects send and the reverb input. This provides more control than the pre‑delay found in most reverbs — for example, adding a bit of feedback can create a more complex reverb effect.

Undead Compression

If you're using compression as an effect (as opposed to preventing tape saturation or some other utilitarian application) but don't like that squashed kind of sound, patch the signal to be compressed through the main channel and send its direct out or effect loop into the compressor, then return the compressor to a separate channel (as in Figure 1). Use the compressed channel as your main signal, then bring up the unprocessed channel, to restore some of the dynamics.

Bigger Stereo Piano & Guitar

Here's an effect you can use on guitars to create a wider stereo image with two mics; it also works well with piano. 'Y' the main right and left channels to two additional channels, using either a Y‑lead or a send from the direct out or effects loop send. Pan the main left and right channels left and right, and centre the other two channels (Figure 2) but bring their levels down about 5‑6 dB (or to taste). This fills in the central hole that normally occurs when you pan the two main signals to the extreme left and right. While you're at it, experiment with adding reverb in different ways — only the main channels, only the middle channels, weighted toward the left, weighted toward the right, and so on.

Aux bus Fun & Games

Get creative with your aux send processing — there's no law says that you can use only reverb. Here are some favourites:

• Add a mild distortion device (a SansAmp, tube preamp, or something similar) and send it drum tracks, bass, or whatever.

The distortion can add a nice edge and warmth; bring it back at a fairly low level at first just to add a bit of crunch.

• Feed one aux send to a vocoder carrier input, and another send to the vocoder's modulation input. Note that this requires a real vocoder with two inputs, not one of the digital simulations that have only one input (and perhaps an additional input for MIDI control). This allows any signal to modulate any other signal, which can provide a very cool effect if you take something percussive as the modulator input and use it to trigger a more sustained part, such as bass or long piano chords.
• Missing that Roland Space Echo you sold at a garage sale years ago? For that unmistakable tape‑echo sound, patch a pair of aux sends to an analogue 2‑track, 3‑head recorder set to Record. Roll tape, and patch the playback head outputs to the effects returns. You'll end up with a slapback echo which has that warm analogue quality. If the deck has multiple speeds and variable pitch control, so much the better. For a truly grungy delay, use this technique with a 3‑head cassette deck.
• For some audio excitement, I often patch the Aphex Model 104 Aural Exciter into an aux buss send/return rather than use it in‑line on the entire mix. Although this kind of unit was originally intended to process an entire mix, these days it's not uncommon for samples to already be 'excited' (particularly drum samples), and adding more exciter on top of that can give a really tinny sound. Adding exciter selectively, using the aux buss controls, gives a much more controlled mix. But note that some of these devices do not allow for cutting out the straight signal so that you have processed sound only — a necessity when you're using exciters in an aux loop context. However, a simple hardware mod can often do the trick (for example, if you're an AOL user, the Articles Library in my AOL site, keyword SSS, has an article on how to modify the Model 104 so that it outputs the effected sound only).

Thanks to Spencer Brewer and Jay Graydon.