With Flow® Mastering Suite 1.2 (2.5.96 and newer), you can now add an external sidechain to allow for a reference track to compare the tonal balance, loudness, and dynamic range. Here is how to set it up in your DAW:
Pro Tools
Pro Tools does not allow the setup of stereo sidechain, but you do have the ability to send a summed mono sidechain. This allows you the ability to compare the frequency and dynamic range of your reference to your master.
Load your track to be mastered and then load your reference track to a separate track. Then mute the reference in the mixer to not hear it on playback. Next, create a send and send to a bus such as Bus 1. Option-click the fader to set it to zero. Now make sure that send it set to pre fader, since we are muting the track, but still want to send to the bus as our sidechain.
Load the Flow Mastering Suite plug-in directly on the track that will be mastered. In the key input menu on the top left select the bus that you created with your reference track.
In Pro Tools, by clicking the external sidechain button, the audio that plays back will sound in mono. If you want to hear your reference track, it is best to solo that track from the mixer in Pro Tools.
Logic Pro X
In Logic Pro X, load your track to be mastered and then load your reference track to a separate track. Then mute the reference in the mixer to not hear it on playback.
Load the Flow Mastering Suite plug-in directly on the track that will be mastered. In the sidechain menu on the top right, select audio and then your reference track.
By clicking the “Monitor Ext. Sidechain” button on the input panel, you can toggle between your master and your reference.
Ableton Live
In Ableton Live, load your track to be mastered and then load your reference track to a separate track. Then mute the reference in the mixer to not hear it on playback.
Load the Flow Mastering Suite plug-in directly on the track that will be mastered. Close the plug-in and look down in the audio effects section of Ableton Live. In Flow Mastering Suite, select your reference as the sidechain. You can now re-open the Flow Mastering Suite plug-in.
By clicking the “Monitor Ext. Sidechain” button on the input panel, you can toggle between your master and your reference.
Cubase
In Cubase, load your track to be mastered and then load your reference track to a separate track.
Load the Flow Mastering Suite plug-in directly on the track that will be mastered. On the plug-in, click the “activate sidechain” button at the top and click the dropdown menu to the right for sidechain routing. Click “add sidechain source” and select your reference as the sidechain. To the right of the level slider is the pre and post fader sends. Click it to send Pre-Fader. Make sure to go into your settings and under VST, uncheck “Mute Pre-Send when Mute”. Now we can mute our reference track and know that the Pre-Fader send will still send signal to the Flow Mastering Suite plug-in.
By clicking the “Monitor Ext. Sidechain” button on the input panel, you can toggle between your master and your reference.
Studio One
In Studio One, load your track to be mastered and then load your reference track to a separate track.
Load the Flow Mastering Suite plug-in directly on the track that will be mastered. On the plug-in, click sidechain at the top and then select your reference as the sidechain. By selecting Output instead of Send, your reference track will only play through the Flow Mastering Suite plug-in.
By clicking the “Monitor Ext. Sidechain” button on the input panel, you can toggle between your master and your reference.
Using Reference Tracks in Flow Mastering Suite
By clicking the “Monitor Ext. Sidechain” button on the input panel, you can toggle between your master and your reference.
For deeper visual feedback, you can select to monitor your sidechain in the frequency section. Under channel configuration, make sure to select “Out/Sidechain”. Now you can see the frequency response of my track with the bright outline and compare it to the reference with the lighter hue.
The dim feature in the bottom right of the plug-in allows you to keep the plug-in open but check the analyzer in the background.
You can also compare the loudness of your reference track. Click “show sidechain” under dynamic range and the top waveform will show your track with the bottom waveform showing your reference.