Panning, or placing sounds in a stereo field is one of easiest ways of creating space, depth, and dimension without having to grab for any mixing tools. It's an essential part of the mixing process, and somewhat an art of itself. Provided we approach it with the right knowledge, we can really make our mixes pop with the right panning.
The first way to approach panning is to think about our audio in three dimensions, which is sometimes a difficult thing to wrap our heads around. For most of us, we're mixing audio for a stereo medium, like radio, CD, ipod, or online streaming. There are typically 2 speakers involved, one on the left and one on the right. But at this point you may ask, "So how do I make three dimensions with two speakers?". Before we answer that, it's important to know a little bit about how our brains localize sound, and figure out the difference between a mono and stereo signal.
Our brain localizes sound in many different ways. One of those ways is being able to judge the difference in volume between our left and right ear. If a sound is louder in our right ear, we perceive the sound to be coming from the right side of our head. And if it's louder in the left, we think it's coming from the left. If the volume is the same in both ears, we think it's right in front of us. The other way we localize sound is by judging the time differences between our left and right ear, but we'll get into that in another article. Still following along?
When we take an audio signal, and play it out of both the left and right speakers at the same volume, we can hear a unique phenomenon known as the "phantom center". If we close our eyes, we can picture the sound to be directly floating in front of our face. This is something more evident with proper speaker placement, and a proper listening position, but it's something that really seems to jump out of the speakers when it's there. The phantom center is our best friend when first learning how to pan properly, so it's important to be able to achieve this first before turning those dials.
Audio Signal Summing
Before we continue, let's get some of the geeky stuff out of the way. We don't typically think of our audio signal in terms of physics. In the real world, audio is a pressure wave. But when we record, we are able to turn those pressure waves into pulsating and vibrating electrical signals. Lucky for us musicians, we don't normally have to think of that kind of stuff. But if you take anything from this section, know that all of these types of waves share one common phenomena. When we have two waves that are in sync with each other, the power or amplitude of the wave doubles. What does this mean for you? When certain frequencies collide, their volume increases and can make our audio louder either as a whole, or only in certain frequency ranges. We'll see how this fits in with panning in a little bit.
Mixing in Mono
Next time you sit down to mix, don't immediately grab for that pan knob and follow the pan recipes we all read online. Before grabbing any eq's, compressors or reverbs I like to sit down with all of the instruments in my mix panned center. Meaning that mono sources will come out of both speakers at the same volume. I typically will get the faders set properly before moving things left and right. Get it sounding balanced. It doesn't have to sound good, just balanced. There are several reasons for this. First, it allows us to compare the loudness of the different frequencies of our instruments, or their natural eq, and it helps us to see what is really needs some help from our EQ's. Next, it gives me a chance to really "hear" the recording as if it was an instrument in the room with me. I can usually make a pretty good judgement on things that are sounding like they were recorded further away just by listening to the frequencies. And because our brains don't have to focus on localizing sound, it truly lets us hone in on the sound of our instruments.
At this point we're ready to start panning things left and right. One thing that we've hopefully noticed when setting up our mix in mono are the instruments where frequencies are clashing. These are prime candidates for panning. Moving instruments with clashing frequencies apart, can sometimes be the determining factor of grabbing an EQ.
Determining where instruments will be placed in our mix, it's sometimes best to think about a real world performance scenario. I like to close my eyes and picture each instrument as if it were in the room with me, and use the pan knobs to trick my brain into "placing" these performers in my room. There is a trick to this though and that is by thinking of how far away each instrument will be from us.
I generally stray from the hard-left/hard-right idea unless something absolutely needs to be "in your face". If you think about it, when we're close to an audio source there is a greater difference in space between those signals making them appear to be coming more from the left and right. The further away we get, the more narrow that sound becomes. For stereo mic'd instruments like drum overheads and piano tracks, try starting with them panned center, solo them, close your eyes and slowly pan them left and right. It will quickly become evident how panning something more narrow will increase distance and depth in your mix. Another way to think about it is sitting in the front row of a rock concert. You have two guitar players on each side of you wailing away. It's a very in your face sound! But as you move 20 more rows back, the sound begins to narrow, congeal and it doesn't seem so in your face and wide. Try to represent these situations with your pan knobs. When panning, I also like to think of the center mark on the knob as a pointer. So when I turn it, I'm "pointing" that instrument to a particular place between the speakers.
We're almost there! Every analogue console, and DAW has a pan law. This will tie into our mini physics class we had earlier where we were talking about summing audio signals. If we have an audio signal panned center, those identical signals collide and their power is doubled. Remember that anytime we add or subtract 6db to an audio signal, we perceive it to be twice as loud, or twice as soft. In a regular situation, this would result in center panned signals being twice as loud, or 6db louder, as the same signal being panned left or right. To compensate for this, electronic and software panners use a "pan law" which reduces center panned signals by 6db. That way, when we pan a signal hard left or right, it sounds like the same volume as when it's panned center. Many DAW's offer the options to choose different pan laws, which can be used to compensate for inconsistencies in our listening environment if it's less than perfect.
So which pan law is technically the correct one to use? The -6db option will give us the correct balance for signals panned across a stereo field. Sometimes you'll see where -4.5db is used in software, to work around different inconsistencies, but just remember that it's essentially 2.5db louder (the difference between -6db and -4.5db) when panned center, and you may need to adjust your fader if center panned signals seem to be too loud.
To end our brief lesson on panning, the best tip that I can give is to close your eyes when panning and try to sense those intruments in the room with you. I've often seen where toms are panned unnaturally hard left and right. Think about the toms of the drum kit, close your eyes, and point your finger in the direction where they should be coming from as if they were 5 to 10 feet away. You'll notice that the difference between the instruments often isn't as great as we think they should be. Shoot for realism and depth in your mixes before grabbing any other tools and I think you'll be able to take panning to the next level.
For even more awesome tips, tricks, and instruction on panning and pan laws, be sure to check out Panning Explained, a full hour and a half series on mastering the art of panning today!