Jimmy Douglass outboard gear on the mix bus

These days, inserting outboard gear on your mix bus is simple, thanks to the external hardware plugins found in most DAWs. Routing your signal out to a piece of hardware can add an analog vibe to your otherwise in-the-box mixes. It’s certainly helpful for Jimmy Douglass in this excerpt from Start to Finish: Jimmy Douglass - Episode 16 - Mixing Part 6. He uses a pair of Neve VR Strip rackmount processors to do some tasty mix bus EQing.

The units are rack versions of the channel strips from a Neve V-Series console. Jimmy is clearly quite comfortable using them. He knows how the EQ bands will respond, and he adjusts them almost by feel. On this occasion, he’s not using the compressors in the channel strips.

Jimmy tweaking the mix bus EQ using a pair of Neve VR Strip processors.

He adjusts the EQ knobs at 60Hz, 100Hz, 7kHz and 10kHz. He doesn’t specify whether he’s boosting or cutting, but it sounds like the latter, particularly in the two higher bands. When you hear the comparison between the mix with the Neve modules active and bypassed, the EQed version sounds significantly rounder and warmer. Jimmy points out that some of the sonic improvement he’s getting comes simply from sending the audio through the Neve circuitry.

Outboard on the Mix Bus

The decision to send your mix to an outboard device isn’t necessarily a sonic slam dunk. The quality of today’s DAWs, recording at 24-bit or 32-bit-floating point resolutions, is so good—as are that of many plugins, including analog-modeled ones—that you can often get excellent results without leaving the box.

Some of it depends on the musical style. Genres like contemporary hip-hop and EDM have many of their production roots in digital technology. For those styles, the ultra-clean sound of digital audio isn’t usually considered problematic. Although “Light Shine Through,” leans heavily to the electronic side of pop, the analog Neve channel strips play an important role in shaping the tone of the final mix.

Outboard hardware used to be clearly superior to plugins in sound quality. But contemporary plugins have come a long way sonically. Now, the choice between analog hardware and software processing is more a matter of taste and cost—plugins are considerably less expensive. It’s also sometimes a matter of age, as producers and engineers who began their careers in the pre-digital days are more inclined to use hardware than those who grew up with plugins.

Assigning a hardware insert in Pro Tools.

Digital Converts

If you do opt for hardware, it’s not just the quality of the processor that’s important, but that of your converters, whether they’re in your audio interface or standalone units. When you use a DAW’s hardware insert in a DAW, the signal must get converted from digital to analog to go into the processor and then from analog back to digital to return to your DAW.

If you have an interface with inexpensive converters, you may find it sounds better to stick with plugins rather than sending your mix through that extra conversion step. But as with any aspect of mixing, your ears should be the final judge.

Remember, too, that if you’re processing on the master bus, you need either a stereo hardware processor or two identical mono units (preferably linkable). Otherwise, their differences could throw the stereo image out of whack.

Slightly Late

Your DAW’s hardware insert plugin is the most straightforward way to incorporate outboard gear on your mix bus. It will be subject to latency because you’re sending the signal out of the DAW and back in again. Latency would be more problematic if you inserted a processor on an individual track or group. Then you’d have to adjust delay compensation to line it up with the other tracks because otherwise, the latency would cause the processed track to be late.

Hardware insert plugins from (left to right) Ableton Live, Steinberg Cubase, MOTU Digital Performer and Apple Logic Pro X.

But because a mix bus effect impacts the entire mix, you should only notice latency if you switch your monitoring between the processed and unprocessed signals. As long as you’re listening to one or the other, you won’t hear the delay.

Alternate Routes

Besides using your DAW’s hardware inserts, you have other options for setting up master processing on your mix. If your studio has a summing amp with inserts, you could send the entire mix out of one of the output pairs in your DAW. Route the analog output through the outboard processor and into one of the summing amp’s input pairs or into the summing amp with the processor inserted. You’d record the processed output of the summing amp onto a new stereo track in your session.

You could also wait and add your master effects to the mixed stereo file during mastering. Some engineers and producers don’t recommend doing it that way because they say it’s best to have your mix bus effects on the whole time you’re mixing so that you can “mix into them.” That is, by hearing the mix bus EQ or compression as you’re adjusting levels, panning and adding other effects, they’ll be more integrated into the overall sound and direction you’re going for.

Mix bus effects are usually pretty subtle. If sources in your mix need a heavy dose of compression or EQ, you’d typically apply that directly to individual tracks. Mix bus processing is generally not corrective as much as it is a global tweak of frequencies or dynamics applied as “icing on the cake.”

Testing One, Two

To show how close the results can be between using hardware and mixing entirely in the box, here is an example of a mix using both approaches so that you can compare. At the end of the article, we’ll tell you which one is which, but first, see if you can hear the differences.

The UAD SSL G Bus Compressor plugin.

One of the examples has no effects. Another has a Warm Audio Bus-Comp, a stereo VCA hardware compressor. Another has the same compressor along with its switchable Cine-Mag transformer circuit active. And one has a UAD SSL G Bus Compressor plugin inserted with similar settings to the Warm Audio hardware. Also included is the unprocessed version. Here they are in random order. Listen and see if you can tell which one is which.

Example 1

Example 2

Example 3

Example 4