Mix Bus: Stems and Hidden Tracks

For me, one of the handiest features of working with a software mixer over a physical mixer is that I can hide channels I don’t need to see. In this article, I’ll explain how to use stems and memory locations to group and hide channels in the Pro Tools mixer.

Using stems is the same as creating subgroups or buses to premix parts of your session to a fewer number of faders, usually for processing. The way I use it most often is to take individual percussion instruments and combine them onto a single stereo fader. I’ve also used it to simplify working with background vocals, horns, and strings. After hiding the source tracks, you can really reduce the clutter of your mix.

In Figure 1, you can see a few channels of the mixer in a session I’ve been working on called “I’m Gonna Rock”—a song I wrote with my 9-year-old niece. In order to fit all 21 tracks on my 18-inch monitor I have to use the Narrow Mix setting under the View menu. It’s not my favorite way to work, because in order to squash each channel, Pro Tools abbreviates text up and down the strip. And there’s less throw in the horizontal pan sliders. Like many people, I use external percussion instruments such as BFD, Strike, Drumagog, and Reason, and I like to be able to keep all my volume controls and automation in Pro Tools, rather than switching between applications. So Reason just sits in the background, and the MIDI is right there in Pro Tools.


In this session, I have eight percussion instruments and a stereo set of handclaps. Instead of sending them to the mains on Audio Out 1–2, I sent them to stereo Bus 1–2. Then, I created a new stereo Aux Input track. It’s important not to just create another audio track, because it won’t accept input from the buses (I pulled some hair out over that one). On the Input button, I selected Bus 1–2, and I set the output button to Out 1–2. In Figure 2, you can see a Tom track on the left being sent to the DM (drum) Stem on the right.

At the same time, I created a second Aux channel and set its Audio Input Path selector to Bus 1–2—just like the stem. On this channel, I inserted a D-Verb set to Small Ambient to give the drums and handclaps a little room sound. If I’d wanted to put the handclaps in their own space, I would have added a send selector to each of the percussion and handclap tracks, and I probably would have used Bus 3–4 for percussion, and Bus 5–6 for handclaps. As it is, I did send the snare and toms out to an additional bus so I could add a more spacious auditorium-type reverb.


Then, I muted everything except the percussion tracks, and did a rough mix of them in relation to each other—both in volume level and stereo panorama. The easiest way to do this is to create a Group for the percussion tracks, and then click the Solo button on any of those tracks. I Shift-clicked on each of the percussion tracks and the DM Stem, went to the Track menu and chose Group. In the Type area, I selected the Edit and Mix button, and I checked the boxes next to Mutes and Solos as in Figure 3. So far, so good. But then it started to bug me that the percussion tracks were all the way over on the left of my mixer, and the Aux tracks were on the right. Oh, sure—I could move the Aux tracks over next to the percussion. After all, they’re just virtual tracks. But I like to keep my sessions consistent with the processing over near the Master fader. So here is where I started hiding tracks.


As all tracks were currently showing, I created a new memory location titled Show All. Now here’s the cool part: In the Time Properties area, I clicked the None button, and in the General Properties area, I checked the box next to Track Show/Hide. This doesn’t create a memory location at all. It just remembers what tracks are showing. Brilliant!

After I had that set of tracks memorized, I created other “locations” with fewer instruments. In the track window, I displayed the Track List pop-up. Then, I clicked on all non-percussion tracks (excluding the effects channels) to hide them from the mix window. Next, I created a new memory location titled Just Drums. Finally, I redisplayed the other tracks, and hid all the drum tracks except for the stem. I created a location for that called Hide Drums. Now, by typing the key combinations for those “memory locations” on my numeric keypad, I can hide and display the drums at will. (How you recall memory locations differs, depending on whether Numeric Keypad mode is set to Classic, Transport, or Shuttle.)


One thing that happens when you solo a stem track is that the source tracks don’t play, leaving you with silence. That’s just not going to work! The way around that in this example is to set the percussion tracks to Solo Safe. Simply Command-click (Macintosh) or Ctrl-click (Windows) on the solo button for each of the percussion tracks. The Solo button will turn gray. Now, I can hide the tracks and control whether they all play or not by soloing or muting the single stem channel. So after a little organizing by stems, I only need to concern myself with ten full-width channel sliders, rather than the 21 narrow channels I started with.

Other Pointers

If you add other tracks to your session, you may need to edit your show/hide memory locations. Select a location, and add or subtract tracks until it looks the way you want. Then Control-click (Mac) or Start-click (Windows) on the memory location. Once the Edit Memory Location dialog appears, simply click OK.

But be careful! If you Option-click (Macintosh) or Alt-click (Windows) on a location, you’ll delete it! The keys for Delete and Edit are very close to each other. The good news is you can Undo if you mess up. You may also need to add or subtract from any Groups you’ve created. Just double-click on the letter to the left of the group name to bring up the Modify Groups dialog. Then, double-click items on the left to add them to the Group, or on items to the right to remove them from the Group.

Finally, if many of your sessions use a similar setup, I suggest you make a template. That way, you’ll have all your tracks with their names, stems, groups, and memory locations already set up. Save the current session under a different name and location. Then, remove all the MIDI and audio tracks and any automation. I also clear the tracks from the Regions list. Be a little cautious about that process. When presented with the Clear Regions dialog, the Remove button is the correct choice. If you use the Delete button, you’ll permanently remove the regions from the other session on your hard drive. Not good!

The End

So there you have it. You can simplify your mixing by using stems and hiding tracks. You’ll only have to use this technique a few times before it becomes second nature. There are some wonderful tools here. Start using them!