The Problem:
One of the most challenging problems people run into when recording in a home studio environment is something called out of phase audio.
Think of phase as follows. The simplest way is to imagine a graph. The position of a sound wave against the x-axis of the graph can be correlated to phase.
When a sound wave is shifted forwards or backward in time along that spectrum, you introduce something called a phase shift.
Once this happens, simply put, destructive interference occurs and causes the sound integrity to essentially degrade and will cause some parts of the sound audibility to disappear.
If you had to duplicate an audio signal and completely reverse the phase, it would altogether cancel out, and you’d have no sound left.
When you record with two or more microphones, these types of problems can really become a huge pain.
This is why keeping things in phase counts a whole lot to getting those punchy, full-spectrum drum recordings, and today, I’m going to run through a couple of pretty neat ways to ensure that you’re getting this right.
How to hear if something is out of phase?
It’s quite easy to hear if something is out of phase, by listening to two or more tracks in combination. If they sound thinner or different when combined together, they’re probably out of phase.
Can it be fixed?
Yes! It can be fixed. There’s a couple of helpful tips, thoughts, and pieces of advice on how you can approach these things, both with stock plugins, recording methods, as well as third-party plugins!
1. When Recording:
When you’re recording, just like your plugin EQ that has a phase invert button, many pre-amps have that same button!
Try switching it off and on and see which one sounds better if your low-end energy and power returns, and you’ll discover if your recordings are out of phase with each other before even doing the first take.
An example of this could be something like recording both the top and bottom of a snare drum with two different microphones. The sound resonating from the snare drum is probably going to be out of phase, so be sure to check on things like this.
This can be a problem with any multi-mic recording. Overheads, guitar, piano, etc!
2. Fix the Phase in the DAW
You can somewhat fix the phase of something inside your daw with stock plugins, in a couple of ways.
It’s possible to do the same thing you’d do with your preamp, in your DAW, and it depends on a few different situations.
If you’ve got two separate recordings of your snare drum(top and bottom mic) and when you play them together, it sounds out of phase, you can simply open up the one audio files properties(or use a plugin like relay from izotope or a stock EQ plugin) and click the phase invert button. This should help it get back in phase.
If you’ve got a stereo file that sounds of phase with itself(for example, an electric guitar track with multiple effects that sounds out of phase and thin), you can split that stereo file into 2 mono files, and then simply flip the phase of the one mono track and you should be in a much better position.
While this may not completely solve your problems, it’s going to get you closer than where you originally were.
You can also shift the tracks by milliseconds to try to find a point where it sounds most in phase. Not always super easy, but if you’re desperate, it’s worth a shot.
3. 3rd party plugins
The 3rd party plugin I’ve come across that seems to bring quite a comprehensive and powerful tool to the party, is Auto-Align from Sound Radix.
This plugin actually automatically fixes both the delay in the signal that can assist in improving phase correlation, but also fixes the polarity!
What this means, is it can detect if something is out of phase, Auto-Align can fix the phase issue caused by the multi-mic recording of a single source. When summed in a mix, each mic causes a phase shift that varies throughout the frequency range and cannot always be fixed using a phase rotator. Auto-Align automatically detects the distance and the delay between the mics and compensates for it with great accuracy.
This is great for quickly and simply fixing your phase issues without having to go through the tedious process of manually doing it. Totally worth adding to your arsenal.
Bonus Concept - Dynamic Phase Adjustment?
While I was testing out auto-align, I stumbled across something else that greatly intrigued me. I thought I’d share what I found. What if you could dynamically(in real-time) adjust the phase of everything, even non-recorded sounds in your mix to perfectly correlate together from the beginning to the end of your song?
Enter, PI - also from Sound Radix
At first, I didn’t understand what they were trying to achieve. But with closer inspection, this actually greatly surprised me.
Pi, is a multi-channel-aware dynamic phase rotator. It analyzes the tracks in your mix in real-time and constantly rotates their phase to improve phase correlation. Pi minimizes cancellations of overlapping frequencies when they interact with each other.
This appears to have the ability to actually optimize, and improve your overall mix by dynamically optimizing your entire songs phase correlation.
For example, sometimes, a kick and bass might have a corresponding frequency that slightly cancels out when both signals play at the same time on that particular frequency. As a result, level is slightly lost. This could effectively improve that problem by dynamically rotating the phase to fit perfectly between the two sounds.
Now that, is really, really, cool. Check them out!
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Thanks for stopping by! We hope this was an interesting read and helps you make better music!