Crossfading Zones

A nice musical effect is to be able to smoothly fade from one sound into another. You can easily do this with a single slider (or other continuous controller).

1. Follow Record 13803 ( from this database )to create a 2 zone, layered Setup. To best demonstrate the crossfade effect, you should pick two sustaining sounds for the two zones, such as strings and organ, or two different sounding organs. If you have the VGM board in your unit, try using two similar orchestral sounds, like Oboe and English Horn, or Recorder and Pan Flute.

2. Hold the Controllers button and move Slider A. If the display is not on zone 1, press the Zone 1 button. The display now shows Zone:1 Slider A, Ctrl Num:None. Press 7, then Enter to assign Slider A to Volume.

3. Press the >> button once. Notice that Scale is set to 100%. Press >> again. Notice that Offset is set to 0. Press >> again. Set the Curve to Sin+.

4. Press the Zone 2 button. Press the << button three times so that you are back to the Ctrl Num parameter. Set this zone to Volume, just like zone 1. 5. Press the >> button. Press the +/- button, then 100, then Enter to set the Scale to -100%.

6. Press the >> button. Set the Offset to 127.

7. Press the >> button. Set the Curve to Cos+. Hold some notes on the keyboard the keyboard and move the slider up and down. You should hear one sound fading into the other.

8. Name and save your Setup.

OK, so what is happening? Zone 1 works like normal – moving the slider up sends volume values from 0 up to 127. But in zone 2, the slider starts off at 127 (because of the offset) and then decreases in value to 0 as you move the slider up (because of the negative 100 percent scale).

What about the curve parameters? They change what values are sent as you move the slider from the very bottom to the very top. With a Linear Curve (essentially no curve), the values change in even spacing as you move the slider up. With a Sine+ Curve, the values are spaced close together when you first start to move the slider up, then are gradually spaced farther apart after the halfway point. A Cosine+ Curve works the opposite – the values change slowly when you start moving the slider and then change faster after you reach the midpoint.

So why not use a Linear Curve in the crossfade? It is beyond the scope of this tutorial to detail dB issues involved when you layer sounds, or to cover how instruments respond to MIDI volume in dB terms. The bottom line is that if you use Linear curves, the total amount of amplitude for both zones will be less when the slider is halfway than when it is all the way up or down. By setting zone 1 to Sine+ and zone 2 to Cosine+, you will have a smoother volume transition and the amplitude at the midpoint will be about the same level as when the slider is all the way up or down. Try setting both zones to Linear and hold notes while you move the slider, and compare that to using the Sine+ and Cosine+ curves. You should be able to hear a difference.

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