What does panning do in a stereo system

Question

I use pan a lot, but would now like to understand what it does.

My question is spurred on by being told in a mix (a rock band for example) everything needs to live in its own space. Well, surely it can't actually have it's own space since they're only 2 speakers - by this definition if you have more than 2 instruments then you can't have everything in it's own space (and this only works if the 2 instruments are hard panned to opposite speakers)

I've looked into this and the information says it 'pans' to the left and right. Well, is this true or just a concept more that what it is actually doing. In other words, is a pan just a way to increase or decrease volume of a certain speaker. For example, when something is panned at 0 (i.e. centred), it plays at 100% of both L and R. When something is panned L50, it plays at L 100% but R is played at 50% (or whatever % the software / hardware chooses)?

Can any one confirm if my understanding of this is correct or if I'm missing anything. I appreciate this may differ from software/hardware, but my question is general about the concept/theories.

Answer 1

I agree with @AJ Henderson explanation of "Wall of Sound" concept. I'd like to add one more perspective. Some years ago I've ran into a very interesting way to look at a mix. The concept was about thinking of your audio image as of actual 3D image. Where the space can be defined by following means:

• Right\left - panning\balance
• Up\Down - EQ
• Far\Close - Space simulation effects like Reverberation, Delays\Echoes, etc..

I found that concept pretty useful when mixing and trying to give everything its own place.

Regarding the panning issue, I'd like to add that there should be noticed a difference between panning and balancing. I have found a very nice explanation here, but below are the main thoughts:

Panning - adjusts the portion of a channel's signal that is sent to each output channel. Panning sends some of the left recorded channel's level to the right output channel, or some of the right recorded channel's level to the left output channel. Each recorded channel has a constant total output level, which is divided between the two output channels.

Balance is sometimes confused with panning, even on commercially-available audio equipment. Adjusting the balance changes the volume level of the output channels, without redirecting the recorded signal. The default setting for balance is "center," meaning 0% change to the volume level. As you adjust the dial from "center" toward the "full left" setting, the volume level of the right output channel is decreased, and the volume level of the left output channel remains constant.

Answer 2

This is confusing panning with space in the "wall of sound". There are multiple dimensions to sound. At a minimum you have placement in terms of relative "volume." You also have the dimension of frequency from low to high frequencies. You also have left to right placement in a stereo mix and if you are doing surround, you may have additional axis that you can place it along.

The wall of sound that you are referring to with "everything needs to live in it's own space" is about frequencies and EQ primarily. (It also can refer in part to the way the levels are stacked as well.) The idea is that you want the sound to be very full and rich, but also clear and detailed. To do this, you need each instrument and vocal to fill it's own portion of the frequency spectrum. You don't want them to run over each other and muddy the sound, so the EQ may be done differently than it would be if each instrument was playing by itself.

As far as panning specifically, there are two different concepts to know about, panning and balancing. They seem similar at first glance since each has a knob labeled Left and Right, but the difference is in how they behave with a stereo channel. Balance will adjust the levels of the distinct channels but won't change which is left and which is right. Pan on the other hand will determine which channel a signal goes to. If you pan a signal to the left, more of the signal goes to the left and less goes to the right. For a stereo channel, if it is truly a pan, it will move signal that is normally on the right channel to the left.

Put another way, balance is kind of like a paddle in between two streams, you can turn it to either side slowing that stream with no impact on the other. Pan on the other hand is like a paddle splitting one stream in to two. It controls how much of the stream goes to each of the two outputs, but still has the same amount of total output.

Answer 3

Signals can be directed in two directions, Left and Right Panning helps to direct signals either left or right

Thus getting more of the signal's left part or right part respectively