[LOUD DRUMMING] HI, MY NAME’S GREG NORMAN
OF ELECTRICAL AUDIO HERE IN CHICAGO
I’M HERE TO TELL YOU ABOUT THE MID-SIDE
STEREO MICING TECHNIQUE.
[LOUD DRUMMING ENDS WITH CYMBAL CHOKES]
So, the mid-side mic’ing technique consists of two microphones.
One microphone - the “mid” microphone - is pointed straight at the instrument.
The other microphone - the “side” microphone - is pointed 90 degrees to the side,
and you combine the two to create a stereo image in a very special way.
The advantage to this technique over other stereo mic’ing techniques is
there’s always one microphone (the “mid” microphone)
pointed directly at the instrument. So you always have a full-fidelity
pickup of that instrument, whether or not you use the “side” microphone or not.
And that’s handy when you need to mono-up a stereo image.
[RAGTIME PIANO MUSIC PLAYS LIGHTLY].
Here, I’ll show you how.
[RAGTIME PIANO CONTINUES]
So, the mid-side mic technique was developed by Alan Blumlein in the 1930’s,
but it didn’t get taken advantage of until the 1960’s,
[RAGTIME MUSIC ENDS]
and the advantage to this technique is
that you have one microphone pointed at the
information you’re trying to record, like a drum kit or the piano or the ensemble.
And that microphone is always faced in the right direction,
so whatever happens, you always have that fidelity.
And the “side” microphone is just there to add the stereo information.
And he developed it in such that way that would be compatible with mono and stereo.
Because back then, there was no stereo, but he knew there’d be broadcasts and recordings made in
stereo, and they’d have to be played back in mono. And this technique is perfect because if
you take the stereo recording and mono it up, it cancels out
the “side” microphone, only leaving you with the “mid” microphone, which should sound good.
So it’s always good to pick a good microphone, or a microphone you like the sound of
as your “mid” microphone, and just augment that with a nice quality “side” microphone.
So, we have the “mid” microphone, which is represented here,
in a cardioid pattern in blue, and is pointed towards the drums directly.
And the “side” microphone is in green, and it’s the figure-8 pattern as I described.
Now, the positive end of the figure-8 microphone is facing to the right,
negative lobe facing to the left.
The positive polarity will add with the “mid” microphone and roughly double in volume,
and the negative lobe with the bi-directional microphone will cancel out the common information
with the “mid” microphone. So, what you’ll end up with is a
right-leaning cardioid pattern microphone when you sum those two together.
To get the other side, the left side, you sum the “mid” microphone with the phase-reversed
“side” microphone, so when you flip the phase, the back of the microphone is positive polarity and the
front of the microphone is negative polarity. So, everything’s the same it’s just,
now it’s facing the other direction, and you see a roughly cardioid pattern facing the left.
…and a little dingleberry because it’s hypercardioid.
So, in a general sense, that’s how it works. You can have different patterns if you like.
The “mid” microphone could be an omni pattern, or it could be a figure-of-8 pattern.
Both of those things will create different results, and feel free to experiment and have fun.
So, let’s have Sephan record some drums and
see how it sounds, I can solo things and demonstrate what’s going on.
[A BRIEF MOMENT OF SCI-FI SOUNDS]
Alright, dipshit, start playin’.
[STEPHAN PLAYS “CHALLENGE DRUM BEAT”]
[LIGHT CYMBAL TAPPING]
[CYMBAL CHOKE]
Alright, STOP!”
[CYMBAL CHOKE]
STOP! [ANOTHER CYMBAL CHOKE]
[YET ANOTHER CYMBAL CHOKE]
So, now that we have some great recordings to listen to,
we’re splitting the signals out on the console here.
…and this is analogous to any digital console you have in your DAW.
One fader will have the “mid” signal.
Another fader will have the “side” signal panned to the left,
and the third fader will have the “side” signal panned to the right.
The right-panned fader has the phase flipped.
So, the “side” signals have to be exactly the same level in order for this to work right.
And the way I do that is by playing back the recording - just the “side” signal -
panning the two “side” channels together and adjusting the level of one of
the faders until the sound completely cuts out, or the signal is nulled-out -
because they’re out of phase, remember, and they’ll cancel each other out and be quiet.
And when they do get cancelled out completely, you’ll know that the levels are identical.
[PLAYBACK OF “CHALLENGE DRUM BEAT”]
…now it’s getting cancelled out…
[AUDIO GETS INCREASINGLY QUIETER]
…get it as close as possible…
…that’s pretty close.
And now, I’m gonna pan it back to the right.
[AUDIO FADES BACK UP]
[PLAYBACK STOPS]
So now both channels are exactly the same level,
and that’s important, because, if for some reason the stereo signal needs to get mono-ed,
that “side” microphone will disappear, and the “mid” microphone will be the only thing present.
If those channels weren’t exactly the same level, you’d hear a little bit of bleed of
the “side” microphone and it would affect the signal overall, wouldn’t sound great.
…wouldn’t sound perfect.
…wouldn’t be fantastic.
…it wouldn’t - I wouldn’t like it.
…not me.
…maybe some [BEEP]
Now that I have the side channels perfectly matched,
you might want to make sure that they never get nudged or moved,
which makes it hard if you want to change the stereo width.
So, you might want to consider sending the signal - the “side” signal -
to the two “side” faders via another fader, which then feeds the two
perfectly-matched “side” faders.
The reason you’d want to do that is if you want the stereo width
to be wider or narrower with one fader.
[PLAYBACK RESUMES] So, we’re listening
to the “mid” microphone all by itself, which sounds like a decent mono kit microphone.
I’m gonna slowly add the two “side” channels, left and right, in-phase and out-of-phase channels,
and we’ll hear the effect of the stereo field getting wider and wider.
I’m doing it crudely with my fingers, so the level-match won’t
be exactly perfect, but you’ll get the idea.
And, if you, if you’re not wearing headphones,
this is pretty useless.
I’ll do it again.
So, there’s more of the stereo field your’e hearing,
and that’s the effect of the mid-side matrix.
I’ll bring back this “side” microphone a little bit.
…and that’s the mono mic again - the mono, “mid” microphone.
You should notice that the stereo image is getting wider and wider,
and you’re hearing a little bit more three-dimensionality of the room sound.
And I’ll bring it back down just to show you back what the mono mic is doing again.
[SOUND OF A CHOIR SWELLS UP, THEN PLAYBACK AND CHOIR STOP ABRUPTLY]
A couple of notes:
since this takes up so much landscape on your console,
it’s kind of handy to have a box that’s designed to decode the mid-side signals for you.
And that allows you to not worry about a fader being bumped over the course of a long session,
and just gives you the peace of mind.
We built one for our studio. Makes it really easy to do that,
and there’s only one knob to turn up the “side” signal, and everything’s matched,
and everything’s right, and it’s out of the way. There’s a half-a-dozen other companies that
come up with, that came up with a similar sort of thing.
I’d recommend doing that, but don’t be afraid to do it on your console if that’s all you have.
…or in your DAW, because it’s really easy to do that way.
You can also process the individual signals separately with a compressor or an EQ
to create a special effect, like compressing the side channel to make things sound more mono as
the instrument gets louder, or vise versa. If you compress the mon— the “mid” signal, it’ll sound
more stereo as the instrument gets louder. You can have all sorts of fun.
All right, well hopefully you have less questions now than when we started the video.
And you shouldn’t be able to try and experiment with mid-side mic’ing.
It sounds amazing on lots of instruments, sounds
realistic and great and I think you’ll love it, even if you have crappy microphones.
Well, uh, have fun…
[WILDLIFE SOUNDS, BIRD CALLS]
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