Q&A: Achieving Stereo “Fullness”July 22, 2010 6:00 am Home Recording
Thanks for getting in touch. And don’t despair! Your idea for expanding your single-track song by panning copies left and right is spot-on. All you are missing is one concept and some techniques. (It’s not that common to have a song on a single track, but everything I will discuss applies to individual tracks as well.)
Left + Right = Center?
First let’s look at why your approach didn’t work. Picture playing an old 78 rpm record through your stereo system. The record is obviously monaural, or “mono” (i.e. a single channel or source), since they didn’t have stereo in those days. So what happens when you play this record on your stereo? That same mono signal is sent to both the left and right speakers. An important point here is that this is still mono playback, not stereo, even though you are playing it on a stereo system! If you sit between the speakers, every instrument and vocal will seem to come from a point exactly midway between the speakers. Nothing will be toward the left, nothing will be toward the right, because the original source is mono.
Now think about what you did in your experiment. You took two identical signals and panned one left and one right. The result is the same as with the old 78 - what you hear sounds like a single mono source centered between the speakers. The panned-left and panned-right tracks simply “merge” into a centered mono image, as if you had just used your original track and left it centered! Not what you want.
The reason the panned-left and panned-right signals “merge” is because they are identical. The key to achieving your goal of a fuller stereo sound is to make these two signals different in some way, so that the left speaker has something different in it than the right speaker. As soon as this is true you will hear that stereo fullness you’re after.
Vive la Différence
There are three main ways of making the panned signals different from each other:
1. Use different EQ.
If you “roll off” (i.e. turn down) the bass on the panned-left track and roll off the treble on the panned-left track, you will create a pseudo-stereo image in which lower-register sounds, like a bass or kick drum, will come from the right speaker more than the left (since the bass is turned down on the left), whereas higher-register sounds like cymbals or tambourine will come more from the left speaker.
You can hear this effect (which is frankly rather unsatisfactory) on “Only A Northern Song” on the Beatles’ “Yellow Submarine” album. (The result is in fact so displeasing that on the latest re-release they just used a plain mono version, which sounds much better!)
2. Use different timing.
Depending on your equipment, it may be easy or convenient to shift one of the two panned tracks a bit later in time. A delay of about 30 ms (1 millisecond = 1/1000 of a second) is ideal. A short delay like this is not nearly long enough to interfere with the beat of the song or even be perceived as an “echo”. But as soon as you set one side to be 30 ms later than the other, you will hear the stereo fullness really “pop”. This is my personal favorite technique - I use it a LOT.
Beach Boys wizard Brian Wilson is stone deaf in one ear and so all of those 60s hits were produced by Brian in glorious mono, since he could not perceive stereo. But, Capitol Records did not want to release “old fashioned” mono albums just as everyone was moving to stereo. So, they used the time-delay left-right effect I described above, which they called “Duophonic”, on every song. The original releases of all of their famous hits were released in this form. That’s why Beach Boys albums you see at used book stores say “Duophonic” on the top instead of “Stereo”!
3. Use different tuning.
This also depends on the equipment you are using. If you are running Cubase or Logic or similar software on a computer, you can “detune” (or “fine tune”) the pitch of the two panned tracks. A typical maneuver is to tune one of the panned tracks up 2 cents and tune the other down 2 cents. (A “cent” is 1/100 of a half-tone, i.e. 1/100 of the interval between C and C#.) Again, this tiny transposition is nowhere near large enough to throw things “out of tune”, or even to be perceived as a pitch change. Yet, it makes the stereo image “pop” right out at you. I was surprised what a difference this makes.
For completeness, I will also mention that if you put a stereo reverb effect on a centered mono channel, the reverb itself will spread out over the full stereo range from left to right. Occasionally, this alone is sufficient to give that “fullness” that a centered mono track lacks.
I should note again that all of these techniques can be used with individual tracks and parts in a song, not just on an entire mono mix. For example, I often use the time-split left-right effect on the rhythm guitar on a song to keep that part sounding balanced and “centered” without interfering with other mid-frequency parts that actually are centered.Tags: Add new tag, mixing -->