ncimusic

ncimusic
http://www.ncimusic.com
Clarence Street
Grafton 2460
Phone (02) 6641 1700
Fax (02) 6641 1633

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In this lesson the student will

  • gain an understanding using a stereo mid/side recording in the mix

Estimated time to complete 30 minutes.
 

Introduction


In this lesson we will continue mixing our song adding acoustic guitar. We will look at using a pair of mid/side recorded
tracks in the mix to give a stereo effect.
 
Press play in the tool bar below the movie to start it playing.

 

Mid/Side

The Mid-Side miking technique requires two different types of microphone polar patterns: Cardioid, and Figure-8. This is probably one of the best and most accurate stereo miking methods you can use. The problem with this is it must be decoded into stereo. Encoding and Decoding is very simple to alter the spread after the recording using a DAW:

1. Record the mid mic on track 1; record the side mic on track 2.
2. Copy or clone track 2 to track 3. Be sure the waveforms are aligned.
3. Pan track 2 hard left; pan track 3 hard right.
4. Reverse the polarity of track 3 or use an “invert polarity” plug-in.
5. Group tracks 2 and 3 so their faders move together.
6. To change the stereo spread, vary the levels of tracks 2 and 3 relative to track 1.

As mentioned this mic placement technique requires a Cardioid Mic that is positioned in front of and facing the instrument. This mic is the "MID" signal and captures in MONO. A figure-8 mic (the SIDE) is also used in this configuration. It is sensitive to sounds coming from the front and the rear of the mic. You'll position this mic right below that of the Cardioid mic with the front of the mic facing 90 degrees to the left. This is what gives you the stereo width and is used to capture sounds from the left and right sides of the stage/area. Depending upon the mic itself will determine what actual position the figure-8 mic is to be placed under the Cardioid.

 


With these two microphones you end up with two signals but it isn't a stereo signal. The Cardioid (MID) mic is panned to the center with the Figure-8 (SIDE) mic routed to two different channels on the mixer. Pan one of these channels to the LEFT and the other to the RIGHT. Then turn on the Polarity switch for the RIGHT channel. This will invert the phase of the signal. While having an equal amount of signal present in both mics (amplitude is the same) you then can decode the MID-SIDE signal back into the stereo signal. You can change the width of the stereo spread by changing the amplitude of either MID or SIDE channel.

For more CENTER information then raise the MID (Cardioid) channel, for more stereo width then lower the (Cardioid) etc...

 

Conclusion


In the next lesson we will continue our mixing adding electric guitar.