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M/S Recording and Processing Technique

Steven J Stanek February 16, 2017 No Comments

Earlier in the week we did a recording with a B3 organist in a Leslie cabinet and we used the microphone technique called mid-side recording or processing. So we set up and configured the microphone but we did not process it yet. So that’s what I’m going to show you today in our pro tool session.

You can do this in any DAW but for today we’ll be using pro tools and I’m going to start with our first mic right here which is the AEA 44 mic and that is considered our side mic in this recording. So when we initially set the microphone up it was 90 degrees off-axis of the source. So if you’re facing the Leslie cabinet and you turn 90 degrees to your left, that’s where the front of this capsule was facing. And I’m going to go ahead and play it. So it’s pent up the middle and if you can see it on the phase scope right here it is mono and the correlation meter below says that it’s in phase so nothing special there yet.

So the second part of this process is duplicating the side mic. I’ve already done that. You can press, right click and then just press “duplicate”. When you do so all you’re really doing is doubling the signal level. So that’s not very special either. If you play these together it’s just going to be the same source, same signal, just amplified a little louder. So what you need to do is invert the duplicated channel. I’ve already done so by using the audio suite feature and I chose “invert”. But you can also use the trim tool and just press the invert button right there.

Once you’ve done so, if it’s done correctly and you play these two tracks together they’re actually going to phase each other out. So notice minor both pent up the middle right now and the volumes are set at negative 11.2 so…

So I’m playing right now and it is actually not – there’s no sound coming out and that’s because they are completely out of phase. If you look on the screen right here, this is the first microphone right here for the first signal and this is the second. So notice that they are inverted and that will cause it to have no signal source because they are phase canceling each other out. But as I play this signal and I start pending, the signal is going to come through.

So if you’re listening through your monitors or headphones in stereo you can hear the signals coming through hard left and hard right and there’s still problems with the signal because if you look at the correlation meter it’s out of phase and also it shows on the phase scope. This is where the mid mic comes in. We use this to define center mono for this spectrum. So you’re using 3 signals to create a stereo spectrum. So listen and watch the phase scope as I add the – in our case the M300, our mid mic into the signal path.

So as I’m adding the mid mic, the spectrum is starting become stereo. If I lower the mid mic you’re going to see that it starts going out of phase with the correlation meter in the phase scope. This part you can, you know, watch a phase correlation meter or you can actually hear and use your ears, as you bring the mid mono mic up it starts to become a stereo field. And once you find the balance that you prefer and you like the next part would just be to group them together so that you don’t change that balance. So I’ve already done so and you can see the 3 faders moving together. That way during the mix process I can just focus on the average signal passing to the 2 bus as opposed to 3 signals separately.

I do have another mic. It’s called my bottom mic and it’s basically the same M300 that I use for the mid mic but I set it up parallel just facing the bottom portion of the Leslie to capture the low end. And this is where it sounds like… Now all mics together.

We have another mic, it’s called the brauner. And the brauner is a – basically in our case it’s a room mic but it’s a valve stereo dual capsule mic. And the way we use that in this recording is we put it about 2 feet in front of our QRD 20 diffusion panels and we put it in an XY stereo setup. In the capsules we’ll put in a cardioid pattern. So I’ll go ahead and play that for you. Now, all the mics together.

And I do have a reverb channel as well but we don’t really need to use that. So this is a mid-side processing configuration start to finish. So if you have any more questions or comments on this please leave a comment below or email me at steven@acousticfields.com.

This is an unedited transcript from our video series from Acoustic Fields. There will be some errors in grammar and sentence structure that occur during this translation process.

For complete understanding and comprehension, please view the video which is included in this text. For any additional information regarding this topic or others relating to room acoustics, please contact us directly at:

P: 520 – 392 – 9486


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