| Since I have been recording in
my own studio environment for over 25 years, and since I have read a number
of books, magazine articles, taken videotape courses, and read websites
on the subject, I have over the years, both collected and invented a number
of studio techniques that I thought might be useful if I posted them here
- just on the outside chance that someone might come upon this in their
travels....
Some of these I picked up in a course or an article (like the first one
here on Stereo Miking), and others I discovered through need or sometimes
even by mistake. And sometimes I earned the lesson through hundreds of
hours of tweaking and experimentation.
For this first post on the subject, I will write 3 techniques to get
started, but I will have more to add in future posts as well. Here is
the first installment:
Stereo Miking:
Microphone placement is a big part of the art of recording studio techniques.
Things sound different depending upon where you hear them from. To hear
a realistic sound image of an instrument the way you hear it in person,
you need to get a stereo image of it because you have two ears and that
is how you hear things normally. To get a stereo image (a left and a right
track) of an acoustic instrument (like an acoustic guitar) you usually
need two mics (not always - for my Ovation acoustic, I mike one side and
plug in for the other and get a blend of the two distinct sounds). The
question becomes, how do you position the mics for a stereo effect that
is similar to what a real person hears when sitting there in front of
the musician. Part of the problem is something called 'phasing'. This
is caused by the placement of the microphones where one mic picks up the
sound in one section of the sine wave, and the other mic picks it up a
little further away, in another section of the same wave. If the two are
exact opposites, for instance if one is at the peak of the sine wave,
and the other is at the lowest point of the valley, then theoretically
one cancels out the other and there is no sound at all. In reality though,
it is never that precisely opposite so what really happens is a very thin,
weak overall sound when the two are mixed together because part of the
sound from one side is being cancelled out by the other side.
To fix this, you would need two identical mics in EXACTLY the same position
in front of the instrument. The problem then becomes that they pick up
the EXACT same sound, so there is no difference, therefore no separation,
therefore no stereo, therefore no point. So there is a simple technique
that solves this nicely called the “X-Y mic placement” technique.
You take two identical microphones (some even try to buy sequential serial
numbers to get them as exactly the same as possible), then, you place
them one on top of the other pointing directly at the acoustic guitar.
They should be separated by as little air as possible without touching.
The diaphragms inside the mics should line up exactly on top of each other.
Now swivel each mic 45 degrees in the opposite directions, so one is pointing
toward the bottom of the guitar and one is pointing up the neck toward
the head. The mics need to be on a 90 degree angle from each other. This
gives the effect of hearing sounds from each side of the instrument and
the room and the airspace around it AS THEY ARRIVE in the same spot –
like your head does. Because the mic diaphragms are so close to each other,
phasing is decreased as much as possible, and this allows a full, deep,
rich sound, as well as stereo imaging.
The Sound Landscape:
When you go to a concert, you actually hear the instruments coming from
different parts of the stage, That is what gives it that added sense of
reality and depth of space. To create that same expansive feel, I try
to do the same thing when do my final mix down from 32 tracks to a 2-track
stereo image. You can do this using the stereo pan controls on each track
for side to side placement, and also using the reverb and or delay for
front to back-of-stage depth-of-field placement. If you have 3 main vocals,
you can get different effects by placing the singers all together in one
spot, or by separating them across the sound panorama. Keep in mind, that
placing them together will usually give a tighter sound, but you will
sacrifice clarity. Spreading things out geographically, will give a spacious
feel, and a more clear sound, but some things that you might want to sound
tight and together (like some background vocals, or a horn section) might
sound too loose for you intended sound picture.
Here’s how I think of it: Think of painting a picture of the band.
Do you paint all the players in one spot? All in the middle of the stage,
or do you spread them out? Which ones do you group together in one area
and how close are they standing? Well, when you have a mental picture
of where people are standing, then you will know where their sounds have
to come from. Then pan them to their spot on stage in your mental painting.
Use the reverb and delay to place them forward or back in the stage, and
then use volume adjustments to zoom in on someone for special solo parts,
etc. Also consider that people don’t always stand in one place through
the whole song. How about allowing people to move once in a while? Take
a guitar solo and gradually pan it across from center off to the left,
and then increase the reverb as he goes off into the back. Or imagine
the opposite where an instrument or a singer comes from the side and the
back out to center stage for a solo. This is what the automation in recording
systems like Pro Tools are excellent for. Every song has it’s own
settings for everything, and the settings can change dynamically as the
song moves along.
Jigsaw Puzzle EQ Strategy:
One thing often overlooked by musicians (and less-experienced recording
engineers) is that an instrument that sounds great on its own, sounds
different once in the mix with the other instruments. Some frequencies
cut through, and others are trampled by the similar frequencies from other
instruments. In fact, in the general mix of instruments there is often
a general ‘mud’ in the middle somewhere, where the individual
instruments lose their distinction and everything blends together in a
messy muddy way. This is not good, usually. One way to avoid this is to
use the EQ (Equalization controls which control the amount of boost or
cut of each frequency range) on each instrument track to fine-tune the
sound so that the different instruments fit together better. That way
they all contribute to the sound of the ‘band’, but each instrument
can still be distinguished.
To achieve this, I think of each instrument as a puzzle piece. I can carve
away a part of one to make room for a part of the next instrument that
needs to occupy that frequency space in the sound. For example, you might
cut the guitar sound around 200 hz, so that the bass can be heard without
turning it up too loud that it dominates the overall mix. Sometimes you
can achieve sound distinction advantages of a solo by using eq inventively
instead of always using the volume. One rule of thumb for EQing is that
you should generally not adjust the eq for any frequency for any track
more than about 3db. Any more than that, and you have a different problem.
Eq can be used to fix certain problems, but only to a point. Too much
adjustment and it’s a mistake. The sound of the instrument loses
it’s integrity and authenticity.
|