If you want to learn how to use Track Stacks in Logic Pro, it comes down to two types: a Folder Stack that visually groups tracks, and a Summing Stack that also routes them into a shared bus so you can process and control them as one. Both clean up a busy session and make mixing faster.
This guide assumes you have a Logic Pro project open with several tracks you would like to group — for example backing vocals, a drum kit, or a layered synth.
Folder Stack vs Summing Stack
The difference is what happens to the audio:
- Folder Stack: purely organisational. It collapses tracks under one header so you can hide or show them, but each track still routes to its own destination.
- Summing Stack: creates a sub-mix. The grouped tracks feed an aux/bus channel, so one fader, one set of plug-ins and one mute/solo control the whole group.
Use a Folder Stack for tidiness and a Summing Stack when you want to process a group together — a drum bus compressor, for example.
How to create a Track Stack
- Select the tracks you want to combine (click the first, Shift-click the last).
- Right-click the selection and choose Create Track Stack (or use the menu/shortcut).
- Pick Folder Stack or Summing Stack in the dialog.
- Logic groups them under a main track with a disclosure triangle to collapse or expand.
Rename the main track header (for example “Drums” or “BVs”) so the arrangement reads clearly at a glance.
How to choose which type to use
If you are unsure which stack to reach for, ask one question: do you need to process the group as a single signal? If the answer is no — you only want the tracks tucked away so the arrangement is easier to read — a Folder Stack is the lighter, safer choice. It changes nothing about your routing, so there is no risk of accidentally altering the mix.
If the answer is yes — you want one compressor across the whole drum kit, a shared reverb on the vocals, or a single fader to ride the entire group — use a Summing Stack. The trade-off is that a Summing Stack adds an aux channel and a small amount of routing, so it is slightly more to think about. A useful habit is to start groups as Folder Stacks while you are still tracking and arranging, then convert the ones you intend to mix as a unit into Summing Stacks once you reach the mix stage. You can change a stack’s type from the main track’s header menu without rebuilding it from scratch.
Mixing with a Summing Stack
The main track of a Summing Stack is an aux channel carrying the combined signal. Drop plug-ins here to process the whole group at once — glue compression on a drum bus, a shared reverb send on backing vocals, or a single EQ across layered synths. Individual sub-tracks keep their own faders for balance within the group. This is the same idea as a sub-mix or bus in mixing in any DAW; our guide to sends and returns in a DAW explains the routing concepts, and EQ and compression fundamentals covers what to put on the bus.
Mind your gain staging when you sum. Several tracks feeding one bus add up, so a group that peaked sensibly on its individual channels can push the stack’s aux channel much hotter — and a compressor or saturator placed there will react to that combined, louder signal. Balance the sub-tracks against each other first, then set the level of the whole group from the main fader, and keep an eye on the aux meter so the bus is not clipping before your plug-ins even see it. Think of it as two stages: balance inside the group, then place the group within the full mix.
Practical uses for Track Stacks
- Drum bus: sum a kit (from Logic’s Drummer or live drums) for shared compression — the same glue-on-the-bus approach we use when we mix drums as a group.
- Backing-vocal group: control a dozen harmony layers with one fader and one reverb.
- Multi-output instruments: a Summing Stack is created automatically when you add a multi-output software instrument, keeping each output on its own sub-track.
- Big-session tidiness: collapse Folder Stacks to navigate a 60-track project without scrolling forever.
A practical workflow is to stack as you build: the moment you have three or four related tracks, group them. By the time the arrangement is full, the timeline reads as a handful of named groups rather than a wall of tracks, and mixing decisions happen at the group level first, then inside each group.
Common mistakes to avoid
- Putting effects on a Folder Stack and expecting them to act on the group. A Folder Stack has no shared signal path. If you want one plug-in across the group, you need a Summing Stack.
- Doubling up processing. If a track already has heavy individual EQ and compression, then gets more on the bus, the two stages can fight each other. Decide what belongs on each track and what belongs on the group, rather than treating both as catch-alls.
- Forgetting the bus level after balancing. Because summed tracks add up, the group can be louder than you expect. Always check the aux meter once the group is full.
- Nesting stacks too deeply. You can place stacks inside stacks, but more than a layer or two makes the routing hard to follow and easy to break. Keep the structure shallow and clearly named.
Editing and ungrouping
You can flatten a Track Stack to remove the grouping, or drag tracks in and out of an existing stack. Automation and freezing still work on the sub-tracks. To save CPU on a heavy stack, freeze the individual tracks inside it — see how to freeze tracks in a DAW. For wider organisation tips that apply here, read how to organise a DAW project, and find more Logic tutorials in the mixing and mastering hub.
Frequently asked questions
What’s the difference between a Folder Stack and a Summing Stack?
A Folder Stack only groups tracks visually — audio routing is unchanged. A Summing Stack routes the grouped tracks into a shared bus, so you can process and control them together with one fader and one set of plug-ins.
Can I add effects to a whole Track Stack?
Yes, if it is a Summing Stack. Add plug-ins to the main (aux) track and they process the entire group. A Folder Stack has no shared signal path, so it cannot host group effects.
How do I ungroup a Track Stack?
Select the main track, right-click and choose to flatten or ungroup the stack. The sub-tracks return to the arrangement as normal tracks.
Can I convert a Folder Stack into a Summing Stack later?
Yes. Open the main track’s header menu and change the stack type. This is why many engineers start with Folder Stacks while arranging and switch the relevant groups to Summing Stacks once they move into mixing.
Do Track Stacks affect CPU usage?
A Folder Stack adds no real processing load — it is just organisation. A Summing Stack adds one aux channel, which is light on its own; the cost comes from whatever plug-ins you put on it. If a stack is heavy, freeze the sub-tracks inside it to ease the load.
