4. Use an Automatic Alignment Plug-In
If you like the idea of aligning waveforms, but wish there was an app for that, you’re in luck! MAutoAlign by Melda Productions and Auto-Align by Sound Radix are plug-ins designed to analyze audio and automatically apply delay and polarity inversion to align the audio signals. Each one handles two signals simultaneously, making them ideal for common two-track scenarios such as bass DI and mic, kick in and out, close guitar mic and room mic, etc. Both plug-ins have a similar operational style; fast and easy. The plug-ins do the work of comparing audio sources and choosing how much delay to add.
5. Use Hardware Phase Tools
Moving outside the realm of software, there are analog hardware units purpose-built for real-time adjustment of phase relationships. One major advantage is portability—use them at your normal studio, take them to a live gig, or loan them to a trusted friend (and get some collateral). Also, being analog, they don’t induce latency.
The Little Labs IBP is a humble-looking box for modifying a single channel, whereas the Radial Phazerbank is capable of four channels of phase-tweaking greatness. Both offer XLR and 1/4" connectivity, polarity switching, and variable phase via a dedicated potentiometer. The IBP incorporates selectable phase shift range and high or low center frequency, while the Phazerbank utilizes a dry/wet control and a selectable low-pass filter with adjustable frequency.
The workflow with each unit is the same. For mixing applications, do either of the following.
Insert the IBP/Phazerbank directly on the channel needing adjustment.
Send the channel needing adjustment out to the IBP/Phazerbank, then return it to a new channel in your mixer or DAW.
If you are using a DAW to do this, latency will be incurred by the D/A and A/D conversion processes. If your system automatically compensates for hardware latency, no worries! If it doesn’t, then you’ll be creating a phase offset by sending it out of your audio interface and back in. The good news is that the versatile range of the IBP/Phazerbank is likely sufficient to compensate for that.
Phase is your friend, your enemy, and waiting to surprise you at every turn. Remember that visually aligning similar signals makes sense in theory, but ultimately you should consult your ears to confirm if you prefer the aligned sound. Play around with some tracks, experiment with timing, and always listen, listen, listen.