September 17, 2003

Mapping Keyboard Knobs In Logic  [ Edit ] 

I wanted to map the eight programmable knobs on my keyboard onto plugins. This would allow me, for example, to set the tremolo on the Fender Rhodes organ using a knob on the keyboard instead of switching over to the mouse.

There are several steps that one must follow to make this happen. I’ll tell you upfront that I have not been able to do it, because it involves making objects in Logic’s Environment that I can’t make. This story may have a happy ending, though.

First, an explanation. If your keyboard has faders, sliders, knobs, or whatever, it has the ability to send CC messages (continuous control) in MIDI. Logic and other sequencers, and lots of other MIDI processors, can take this information and do stuff with it. In my case, one of the knobs on my keyboard can control the volume of the active track (which is apparently CC#7 by default). I didn’t have to do anything to make this happen, Logic just did it. That gave me hope. Here are some of the things you need to do to make this work.

  1. Find out how to change the CC messages your knobs send. Each keyboard has a different way of doing this. In my case, I push two buttons which put the MK-225 in Control Assign mode, then I twist the knob I’m interested in changing, and punch in the CC number I want it to send. This part is pretty easy.
  2. For each plugin you want to control, find out what CC# your faders of interest listen to. The Logic Users Yahoo Group offers several files detailing the relevant numbers for Logic’s plugins.
  3. In theory, at this point you set you knobs to use the same CC# that your plugin is expecting, and all is well.

Unfortunately, for me it doesn’t work that way, and I think I know why. Logic is receiving the CC messages just fine (watching the MIDI monitor in the Transport, and I see the messages coming in), but then it’s not sending them to the plugin, so the plugin never gets the messages, and the knobs onscreen never move.

This question of how to make Logic’s plugins respond to knobs on your controller seems to fall under the header of Automation. Automation really means setting up your sequencer so it records knob and fader movements (and other similar changes to sound you make while recording or playing back), and can play those movements back for you the next time you play the track. I can see how these topics are related, but they seem different enough that I’d like to think I can ignore automation, since it seems a little more complicated.

In any case, there are two or three solutions to the problem I’m facing.

  1. Learn more about MIDI (let’s face it, I know next to nothing), fuss with the Environment more, bang my head against the wall, and eventually, hopefully, figure it out. [Sigh. There are probably better uses of my time than that.]
  2. Find a tutorial someone has written on how to set this stuff up, and follow it. I found a tutorial in the Sonikmatter forums, and was going to do this. Then I found out Logic Audio 6 can’t create Transformers in the Environment, and that stopped me. There is a workaround that lets you create something just like a Transformer, but this is looking too involved for me. I was able to make the fake Transformer easily enough, but then I don’t know what to do with it.
  3. Buy Fadermapper, which is supposed to allow you to control anything and do lots of other fun things. The demo, which is a time-limited, stripped down version, is pretty confusing for me right now. However, the author appears to give very good support, so I’m sure I could get some help if I invested in it. For now, I’ll wait to think about this until version 2 comes out—apparently Logic 6 (all versions) have a bug that the author is dealing with in the next version.

For now I’m giving up on the knobs. You may be able to find an existing environment at Swiftkick or elsewhere online that will allow your keyboard to work right away, or you could just go for Fadermapper. I hope I can revisit this topic later and come to a happier conclusion.

Posted by Joe | TrackBack

Fadermapper is good for Logic version 5.x only, Mac or Windows. It's unlikely Fadermapper will ever work with Logic 6+.

A better alternative is LC Xmu, which provides Logic Control emulation for generic midi controllers - see

LC Xmu will work with Logic 5.1 or higher on the Macintosh. Mac OS X is highly recommended. There is currently no Windows version.

Posted by: John Pitcairn at May 14, 2004 7:35 PM

Did you use a monitor after the plugin to see exacly what kind of message it sends? Connect an audio object (bus or track...) where the plugin is (as an insert) to a monitor. Move the fader or knob you want to controll and pay attention to the message collected by the monitor. Ex: F 1 120 36 - Fader movement,chan 1, control -1- =120, control -2- =36. If a plugin receives only a fader movement it doesn't do nothing if it receives a control message from your hardware. Another thing on transformers: an object like a fader can receive one thing filter it and send a new message working like a basic transformer, altough it could be tricky. I'm not sure if this brings something new to anyone but I felt I had to share it because I use it in a Graphic Equalizer I made in Logic's environment with 32 parametric eq. Bye.

Posted by: Pedro Ger at May 24, 2004 6:24 AM

Yeah, I used a monitor to see what messages were being sent. The main problem is, Logic Audio doesn't offer transformers in the environment.

Next time I tackle this, I'm probably going to use John's Logic Control emulator. That seems like the most elegant, and easiest, way to do it.

Posted by: Joe at May 24, 2004 11:01 AM
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