(This works with more tracks too.)
It is a common problem. You have a 4-track portable studio, and you want to record a live performance. But the band has more parts playing simultaneously than you have tracks. So you have to decide what to do.
The problem is that there are more parts than tracks. This means that more than one part has to be recorded on some tracks. So you have to choose a method.
Recording each part to only one track, but with more than one part on some tracks - a procedure with the following effects:
Recording two stereo pairs of tracks - a procedure with these effects:
The stereo-pairs method can be arranged so the most difficult balances can be set during the mixdown, and that the remaining balances are either easy to set on the fly, or are not critical. The following are suggestions on using paired tracks to simplify live recording:
During the live recording:
Unless a separate listening room is somehow available, the monitoring of the recording will have to be done with headphones this may alter the pan positions, compared to the location through speakers.
Since balancing the vocals to the instruments is the most critical, put the vocals on one pair and the instruments on the other pair.
The dry signal and the effects from it must be recorded on the same pair. Do not allow an effects return to go to the wrong pair.
You will need two effects units if both vocals and instrumentals need effects. It is normally better to add effects at mixdown, but if some parts on the track pair need effects and others don't, the effects must be added at tracking.
Pan the lead vocal to the center of the vocal pair.
Pan the bass and the drums to center of the instrument pair.
Pan parts working in the same octave differently, usually far apart.
If you have capability to pan into the surround area, a mono reverb can be panned to near the center back of the surround zone. Pan a stereo reverb to the 45 degree left and right positions in the surround zone.
Use an after-fader after-pan (or "in place") solo to adjust critical balances, such as the balance between a piano and an acoustic guitar. After-fader solos are available more on newer consoles.
During the mixdown:
If you have the capability, use an external mixer, and route the signal through both the portable studio's channel strips and the external mixer. This gives you more control over the EQ.
Initially pan the vocal tracks hard left and right.
Initially pan the instrumental tracks hard left and right.
Set the vocal-instrumental balance now by adjusting track levels.
Adjustments to relative levels within the vocals can be made by tweaking the level, EQ, and pan of each vocal track.
Adjustments to relative levels within the instruments can be made by tweaking the level, EQ, and pan of each instrumental track.
Effects added during mixdown must affect at least everything on one track. The best method is to send a pair of tracks to a stereo effect.
A few additional ideas to improve the results:
If the bass and drums overpower the instrumental pair, the following procedure works quite well:
If you have an audience pickup mic and surround panning capabilities, a mono mic can be panned to near the center back of the surround zone on the instrumental tracks. Pan a stereo mic to the 45 degree left and right positions in the surround zone on the instrumental tracks. This technique gives the recording that "you are there" effect, especially if a binaural technique is used for the stereo pickup. But be sure the output of this pickup is in the background of the mix.
BONUS! You can easily mix an instrumental version of the same song by leaving out the vocal tracks.
BONUS! You can easily mix an acapella version of the same song by leaving out the instrumental tracks.