Experiments with reacTIVision

In order to maintain constant levels while mixing between tracks, I needed a way to modulate the gain on the channel both tracks feed into to make up for the dip in volume as the tracks were "cross faded". With my setup, the gain makeup needs to be about +15db at the center, where both tracks are mixed 50/50, rolling off to 0db when a track it at 100%. This requires a convex curve. There no way to do this natively in Live, so I added the capability to the MIDI server in reacTIVion. in addition to the convex curve, I added several other alternative mappings:

binary: values 0-63 are normalized to 0, 64-127 normalized to 127)
inverse: reverse values (eg. 0=127, 16=111)
convex:  0-63 becomes 0-127, 64-127 becomes 127-0
concave: 0-63 becomes 127-0, 64-127 becomes 0-127

Since the MIDI server reads it's configuration from an XML file, it's easy to set these options along with the existing options:


Combining the standard mappings with alternative mappings like this allow X-Y mixing plus the gain makeup control across two axes with a single marker:

The binary remap works well for beat mixing. It allows sharp cuts without having to worry about levels. Setting up a single marker as both an hfader and a vfader with the binary remap lets you divide the table into quadrants. The mappings described on page 3 will work with this setup:


Download the patched MIDI server code
This is an updated version of the MIDI server found in reacTIVision 1.3. Also included are two XML config files that describe the new options.

Thanks to Martin Kaltenbrunner and the rest of the reacTable team for their efforts and for opening the reacTIVision code!