Phase, phase, phase. Ahhh, what can I say about phase? We all love phase! Not.
In my earlier years of recording, I used to post mixes to home recording message boards with the hope of receiving positive feedback. I made these early recordings at home with a small interface I’d purchased, which came bundled with an early version of Cubase. After finally getting the hang of using a DAW and after a few unfinished demos, I eventually had a track ready to post for mix critiquing. The first reply I got back was, “drums sound phasey.”
I knew I forgot something… except I didn’t know what the hell phase was. Did he mean the CAD drum microphone pack I got for Hanukkah didn’t yield major label results right out of the box?! I wouldn’t have put it on my holiday list if I had known that!
All kidding aside, I went to google and searched for “What is audio phase?.” After reading a few websites, I still had barely any idea of what the hell it was and certainly had no idea on how to prevent it. Sure, I understood why it happened, but how was I going to fix something that I couldn’t even hear? I thought the mix sounded pretty good, and I certainly didn’t think it sounded phasey like recorderkid442 on the home recording message board had said.
I’ll start by saying that asking for advice on a message board can be good and bad. Regardless, you must proceed with extreme caution. Posting my question did introduce the concept of phase to me, something that would have otherwise taken me longer to learn about. And that person was right. My recordings were out of phase. But you should still be careful. With every correct answer, there are so many more wrong answers.
Since starting Audio Hertz, I’ve had beautiful interactions with a lot of people, but I’ve also had some interactions with people that are not very knowledgeable and have no problem arguing their incorrect points. Now, this is okay, I understand it is just a by product of the internet and anonymity, but it can do damage to your learning process if people are giving you the wrong information.
I’ve seen terrible cases of this in real life scenarios as well. I had a friend that went to our local Guitar Center to buy a small interface. The Guitar Center employee talked him into purchasing a Presonus preamp, EQ and compressor by saying it would dramatically improve his sound. The salesman told him if he wanted to have a professional quality recording, he needed to have this unit. What the hell is a compressor going to do for my friend who, just moments before, didn’t even know what one was? Nevertheless, my friend bought it and couldn’t shut up about how it was the best thing he’s ever heard. The truth is he didn’t know what the hell he was listening for. And that, my friends, is how bad information gets spread around.
I’m going to skip any technical explanations or definitions and just give you the information that I feel you need to know. Phase cancellation happens when you combine more than one signal of the same source, such as using multiple microphones on a drum set or using two microphones on one acoustic guitar. As sound waves reach different microphones at different times, phases issues can occur, which will make certain frequencies vanish from your mix
First, we need to find out if you’re overheads are in phase with each other, then if everything else is in phase with the overheads, then if the individual elements are in phase with each other.
The easiest way to tell if something is in phase or out of phase is if when you flip the polarity, it should sound worse (when the phase relationship is worse, you’ll hear less low end and smearing of frequencies). That means that the microphones have a good phase relationship and when you flip the polarity, it puts turns that good relationship into a bad one.
I struggled with this for a long time, and I really wish someone had just written out a fast and easy method to check the phase properly. It’s obviously harder to judge what’s in phase and what’s out of phase when you don’t even know what it sounds like, so I highly recommend doing some experiments on your own. Take two mics and a speaker playing music. Start by mic’ing the speaker with both mics lined up perfectly parallel to each other so they’ll be completely in phase. Then put on headphones and begin to move the microphone further away from each other a few inches at a time. You should be able to hear the phase relationship changing for the worse. Once you know what phase cancellation sounds like, you can accurately judge what is in and out of phase. Set up your drum mics and follow these easy steps to correctly recorded drums.
- Put overheads up at unity gain, panned center
- Flip the polarity (by pressing the phase button on your mic pre or using a plugin) on one side, it should sound better when the polarity IS NOT flipped, it should retain more low end
- Keep everything panned center and bring up the snare, flip the polarity and make sure it sounds better when the polarity IS NOT flipped, pull the fader down to 0 after
- Bring up the kick drum, and flip the polarity, does it sound better? If so, then leave it flipped, if not, then flip it back, now pull the fader down to 0
- Bring up the toms, and flip the polarity on the toms, does it sound better? If so, then leave it flipped, if not, then flip it back, now pull the fader down to 0
- Mute out overheads, bring up kick and snare, and flip polarity on one, it should sound better when the polarity IS NOT flipped.
- Keep doing this until you find the correct configuration where everything is working together