Monday, October 27, 2008

How To Use Logic's Transformer to Midi-Gate an Audio Signal

In this tutorial we will dive into Logic's Environment and will see some of the possibilities of it components. For now, we will explain a simple task as transforming a Midi Notes commands to control buttons or faders. Sounds simple right?

You probably thought about Automation, LFO and all sort of other control/modulation tools.
Unlike automation, Midi Notes commands are been use here like a trigger for the signal - Just like On/Off switches. This is the main reason you might want to do this kind of thing. But you may also ask yourself, why should I EVER do such a thing?

well, jump in and you might be surprised.

Step 1 - Choose your tools and signals

I use Logic Pro 8 but as it seems, it can be perform on any version of Logic (even Logic 5.5 for PC!). So, lets open 2 tracks of Audio Instruments.

Then we will load the EXS24 sampler and we'll load an Electric Pad style program. I thought it will be the most effective to see this technique on a pad duo to it's length and the way pads are been used. If you don't have the complete Logic Studio pack, you're using an earlier version of Logic or you just don't feel like it, do hesitate choose a different program / Synth or audio signal. The bottom line, it doesn't matter, you can do it on any audio signal.

The program I've used for this example is located under:
EXS24 > 05 Synthesizers > 05 Motion Sequences > Forma Sweep Trancy

Open Environment window (using "cmd+8"), Make sure that the EXS24 Channel is selected, Click on the out 1-2 and from the Bus Menu choose Bus1. Do the same on Bus1 channel and set it's output to Bus2.

Your Environment Window should look like this:

Note that the EXS24's output is Bus1 and Bus1's output is Bus2.

Step 2 - Create Midi Information

Create a new region of the ESX24 Channel by the particle tool and write down some chords. The chords I've choose can be see on the source files, trust me they are pretty simple and you will not want to use them anyway.

Great, now that we have our sound signal and Midi sequence lets focus on Midi-Gating it.

Setting up Midi Gate notes:
Create another region of 1 bar for the second Audio Instrument channel, loop that channel using the "L" on your keyboard (of course if you didn't change the default key commands).
This, as well, will help us later. Now enter the Piano Roll and write down 16 Notes just like the following picture:

Notice that all Notes play the same key, they have the same velocity and length as well. For your first time, just do as the pictures shows, we will complex things up later (Step 6).

Step 3 - Setting Up the Environment tools

Go to the Environment window by clicking "cmd + 8" or Window > Environment. Create 2 Environment Objects (use the following Picture as guides).

Drag and Place the new objects close to the EXS24 channel and the Audio Instrument 2 channel. The Button object will help us turning on and off as needed the volume of the Bus1. The Transformer will help us set a condition and transform the Midi notes information of Audio Instrument 2 to control the Button (which controls Bus1 volume).
Don't lose me here, I know it might sounds like programming and not music producing, but it's not that complex as it seems.

Back to business...

Search for the White Arrow on top of the Audio Instrument 2. Click-it and connect it to the Transformer. Click on the White Arrow of the transformer and connect it to the Button. Our last cabling will be connecting the button to Bus1 channel.

Your Environment cabling should be ready.

In logic 8, cable's colors are by default so you should get the exact following result.

    Notice 3 Cables:
  • Green from Inst 2 to (Transformer).
  • Light Gray from (Transformer) to (Fader)
  • Dark Gray from (Fader) to Bus1/Aux1.

If you've configure it right, Congratulations! We are almost done.

Step 4 - Configuring the Environment paramets

Configuring the Button object:

Click on the Button and take a look at the right panel of the Environment window. The Setting should look like this:

Notice that I've change the Range of the Button objects, means that this range will effect the maximum and the minimum range of the Midi Controller command. I recommend that you should set the Range to 0-90 (0=.inf 90= 0 db). Besides changing the range, there are no more further setting for our purpose. Moving on to the tricky part...

Configuring the Transformer:

Lets take a look at the needed settings.

The Transformer we see describes a CONDITION (Input) and an OPERATION (Output) that it will transform according to it's MODE.
I our case, The condition is every Midi Notes data should be transform. The operation will Change any Midi Notes information to a Midi Control data. As you see after the information will be transform, the Transformer will "fix" any Midi note pitch into Control number 7 (which will control the button). Finally, Note velocity are represented as Control value, so generally you can change the volume of the mixed channel (Bus1) by velocity. I choose not to do it so I choose to transform any Velocity to the value 90 (which equals to 0db).

Honestly, you don't really have to understand what does it means, you can just configure it as the Picture shows.

If you've set it correctly, you should now something like the following audio:

Step 5 - Complexing Things Up

So we finally done with configuring it and now it's time to play around.
now we'll complex the Gating with different notes length and different rhythmic divisions.

You can play around with velocity as well, just make sure not to assin "Fix" on the Velocity section of the Transformer (leave it as "Thru").

If you will do that, the velocity of the midi note will control the Volume fader of Bus1. I decided not to do that, so it as "Fix".

Step 6 - Adding Effects

Now, that our Midi-Gated-line is done, we can add effects to it.
You should assing all of your effects to Bus2, which is the channel that your finall result lay on.
I added Spreader, Phaser and AVerb effects with the following parameters:

Final result:

I hope you enjoyed reading, ELAD :)