Stereo
All this time we have been referring to a mix as a single signal comprising
of a mixture of individual signals. In reality, stereo is the most
common standard for music distribution and playback. This is nothing more
than 2 individual signals sent to 2 individual speakers.
A mixing desk has 2 main outputs: Left and Right. Each of these must go through
an individual power amp and out 2 individual speakers, in order to give a
'stereo sound'. The left signal and right signal may be slightly different,
for example, if the guitar channel was panned to the left, the guitar would
be louder in the left signal than the right. Most power amps are stereo units,
meaning they have 2 independent inputs and 2 independent outputs, and inside
they have 2 independent amplifiers to handle the left and right signals accordingly.
It has become conventional to refer to a stereo pair of signals as being
a single 'stereo signal'. In actuality it means that the left and
right signals are seperate and independent of each other, and are intended
for independent speakers. Each signal comprises of a mixture of the seperate
microphone signals, just as we have dicussed.
Multitracking
Think of your typical tape deck and the tapes that go in it. The playback
format is stereo, meaning that there are 2 tracks being played at a time.
You will also know that the tape can be turned over and there is more stereo
signal on the opposite side. The tape is actually recorded with 4 tracks,
2 for the 'A' side, and 2 for the 'B' side.
A typical 4-track tape recorder uses the same tapes and technology, except
that it can only be played in 1 direction. There is only an 'A' side
to a tape that has been recorded on a 4-track tape machine. For example, you
can record Bass on track 1, Guitar 1 on track 2, Guitar 2 on track 3, and
Vocals on track 4. When you play the tape back, you can use the faders to
adjust the mix of these instruments. If you were to play the tape in a conventional
tape deck, you would hear Bass on the left speaker and Guitar 1 on the right.
If you flip the tape over, you would hear Vocals in the left speaker and Guitar
3 in the right, both in reverse.
An 8-track tape machine uses the same principle, but it uses wider tape and
has 8 tracks instead of 4. The widest tape you can get is 2inches, and is
used for 16 track or 24 track recorders. These days computers are very powerful
and much cheaper, and generally the sound quality is better. You get better
bang-for-your-buck when buying a computer recording system than a tape-based
recording system.
Overdubs
It is common to record music in stages. For example, your band may record
the basics first, then the giutarist may lay some lead-breaks, and the vocalist
may do some harmony. To do this, you play back the existing recorded tracks
while recording to a new track at the same time.
Eg. In the 'first take', the drums are recorded to
track 1, the bass to track 2, and the rhythm guitar to track 3. Then in take
2, the drums, bass and guitars are played back while the lead guitar is recorded
to track 4.
Before you begin recording, you need to plan which tracks will be used for what.
Your first take will be limited by the number of mics you have and the number of
tracks your hardware can record at once. If you are using a computer with a standard
soundcard, you will have 2 input channels ( left and right ). If you have a
bigger interface, it may provide you with 8 input channels. To use all 8 inputs,
you need 8 microphones and 8 preamps. Many interfaces have preamps built in, but
some interfaces provide a few inbuilt preamps and additional line-level inputs.
Remember from page 2 that a mic signal must first be boosted to line level before
it can be used.
Let's take a look at two scenarios, each involving a band with a drumkit, bass,
guitar1, lead guitar and vocals. In each scenario, it is presumed that the drums
are most important to record first, because it is the drums that set the feel for
the rest of the band.
First up, lets say you are using your computer's inbuilt soundcard. You can only
record 2 channels at a time. The most common approach would be to record the drums
with one mic and the bass with the other, because the bass and drums usually 'gel'
quite well in a live environment. You would then do an overdub for guitar 1, then
another overdub for the vocals. Finally, an overdub for the lead guitar.
Scenario 2 involves an 8-channel interface like the Presonus Firepod. You have 8 mics
and 8 mic preamps. You have far more options, now you can afford to record the full
drumkit and band without doing overdubs. It is common to overdub the vocals anyway
because it prevents the vocal track from contracting the 'spill' from other tracks.
Often you will want to apply effects to the vocal track and not have the effects applied
to the other tracks. To do this, you need to make sure the vocal track only contains sound
from the vocals. So here is a suggestion:
tk.1 = Kick drum.
tk.2 = Snare.
tk.3 = Overhead drum mic.
tk.4 = tom 1.
tk.5 = tom 2.
tk.6 = tom 3.
tk.7 = bass.
tk.8 = guitar.
You can of course do as many overdubs as your computer will allow, the main thing is that
the full drumkit and bass are recorded initially. Later on, you can investigate ways
to record for a better stereo image, but for now, have a think about these scenarios
and what kind of setup would suit you best.
