Software plug-ins have become so good, affordable, and convenient it may seem like rack-mount hardware has become a thing of the past for narration, music, commercials, podcasting, or any other professional recording application. But that’s definitely not the case. Some vintage hardware remains difficult to emulate, while others offer features not usually associated with software (for example, the TC Helicon Voice Live Rack can trigger harmonies from guitar or MP3 players). Also, analog hardware processing is inherently different from digital processing; some people prefer the sound of analog. Many 500-series modules—yet another form of hardware that continues to increase in popularity—may not have software equivalents.
Fortunately, it’s possible to integrate analog (or digital) hardware with today’s DAWs. Some DAWs make it easy; others require more convoluted interfacing. But it’s almost always possible to marry the hardware and software worlds.
External Hardware Limitations
First, let’s cover some important considerations involved in using external hardware with DAWs.
- The computer sends signals to your effect from an audio interface output, and the effect output returns to your system via an audio interface input. So your audio interface will need at least one spare input and output for mono processors, and double that for stereo.
- Hardware can work with only one track at a time. To free up the hardware for another track, record the processed audio into the track where the effect output returns.
- Sending audio out through the audio interface, processing it through an effect, then bringing audio back into the interface adds latency. Some DAWs “ping” this signal path with a test signal to measure the delay, and then compensate for it automatically (although manual tweaking may still be needed). If this isn’t an option, record a single, sharp click (e.g., clave) to a track that’s not being processed and simultaneously, to the track that’s going to be sent through the external effect. Record the sound that’s being processed through the external hardware to a new track; then on playback, line up the clicks for the two tracks.
- Any bouncing or rendering that involves external hardware must happen in real-time. Although DAWs usually offer fast bounce functions to render tracks that include plug-ins, faster than real-time processing can occur only when all processing happens inside the computer.
External Hardware Setups
Assuming your audio interface has enough inputs and outputs, there’s a universal way to use external hardware with any DAW. Assign a track (or bus) output to an audio interface output that patches into the effect, then patch the effect’s output to an audio interface’s input to return the processed signal into the program’s mixer. You’ll need to compensate for latency manually; often it’s easiest to record the effect’s output into a track, using the trick mentioned above of recording a click you can line up with other tracks.
Several DAWs, including Cubase, Samplitude, and Pro Tools have an input and output setup menu that dedicates particular buses to specific external inputs and outputs. You can then call up this “effects bus” as an insert that behaves like a plug-in (Fig. 1).
Some DAWs, like Studio One, include a plug-in that’s designed to make external hardware look like a software plug-in to the DAW (Fig. 2). Typically, this type of plug-in specifies connections and levels to and from external hardware.
These plug-ins have many elements in common, but also, some differences. For example, after configuring the Pipeline plug-in for a specific piece of hardware, you can save that as a preset for later recall, like other effects presets.
The first-time setup for external hardware effects can sometimes be a little difficult; for example, the audio interface may have its own application independent of your DAW. If this application is set up to act like a stand-alone digital mixer, it may be difficult to patch in hardware effects. In this case, simply bypass the application, and have the DAW assume sole control of the interface. Also, there may be nomenclature differences between an interface’s hardware outs, and the way they’re presented in software—for example, your DAW may consider two hardware inputs as a single stereo channel. But once you figure out how to integrate the plug-in with your system, external hardware plug-ins are an easy way to combine external hardware with your software projects.