Instant A/B Switching in Logic Pro…How?
Last night, a good friend of mine asked me this: “Hey, I had this track mastered by two different engineers, I want to load them up in Logic Pro to compare the two versions. I want to be able to A/B switch between those tracks in real time, with just one click.”
Good question. In Logic Pro, soloing regions isn’t instant, and soloing tracks requires two clicks. I couldn’t think of another way than to chop up the second region and put some chops on the first, or to put the two versions inside a Take Folder and switch between versions by comping. That works fine, but doesn’t this call for a simple solution in Environment? All we really need is to invert the ‘polarity’ of switch one (the solo button) and pass that data on to switch two. Setting this up in Logic Pro is easy.
A/B Switching: Logic Pro Environment
All I did was connect a monitor object to track ‘Version A’ to be able to tell what message gets sent out when the solo button is pressed. The monitor object is connected to the Transformer Object, and the Transformer Object is connected to track ‘Version B’.
A/B Switching: Transformer Object
I chose to map a value of 0 to 1 and a value of 1 to 0. Without specifying any conditions, the mute button works the same way. The fader, panpot and sends are now all ‘connected’. In case you don’t want this, narrow down the conditions of the Transformer Object and change its Mode:
Brilliant update: Here’s Bob Kickflip’s approach (see below in the comment section):
I have a more straightforward way, which doesn’t need any Environment work. You need two audio tracks. Put the two files to A/B test on them. One the first channel, set it to no output. On the second, insert a Noise Gate on one of the channels, and set the sidechain input to the first audio track. Now to a/b between them, you just need to click the ‘Monitor’ button.