Qtractor An Audio/MIDI multi-track sequencerAuthor: G3N-es
Resources cited in the tutorial:
Qtractor, although it performs the same task as other DAWs and shares the same nomenclature, has its own unique approach.
This can lead to confusion, as we try to apply pre-learned methods from other DAWs that don’t fit with Qtractor. Ninety percent of the time that I thought there was a error in Qtractor, there wasn’t. On the contrary. I simply didn’t understand its logic. Once I understood it, I discovered that the solution proposed by Qtractor was more fluid and efficient.
In this tutorial, I’ll try to give you an overview of how connections work in Qtractor so you can develop your own audio flows with complete freedom.
When we talk about connections, Qtractor distinguishes between two defined areas.
Input and output ports on buses are not intended for mixing. As much as this statement may surprise you, read this section. You’ll understand.
In other DAWs, the way to connect to a recording and playback device is through a form called “Devices” or similar. In these DAWs, the concept of a port may not even appear. In Qtractor, no such form exists. The connection ports to external devices are the input and output buses. Connections are managed from the “Connections” window. This causes a lot of confusion, especially for people coming from other operating systems. The first thing they do is look for the “Devices” form, and of course, they can’t find it.
However, the approach in Qtractor is much more powerful. You can create as many input and output ports as you want for different purposes. For example, you can create an input bus:
You open it and start recording with everything already configured. I don’t know if other DAWs offer this feature. I know there are DAWs that can do it by track, but not by groups.
Groups. Here’s another difference: In Qtractor, tracks are hosted by buses (groups). There can’t be independent tracks. In fact, input buses are all recording groups. The “default” bus in Qtractor (pre-named “Master”) is actually a group that hosts new tracks by default and assigns inputs and outputs ports to them when they are created. Output buses can serve as group buses, auxiliary buses, or master buses depending on how they are used. They don’t even have to be configured in any specific way. They are self-defined by their use. Everything is defined because it has its own sense.
It’s that simple and logical:
Once users figure this out, they run into another reasonable confusion: “If I create a bus, and it’s duplex and has an input and output… The input bus is the input of the duplex bus where I should connect the signals to be mixed.”
In addition to recording, they’ll try to use the input bus to mix signals… No, it doesn’t work that way. The input and output ports in Qtractor aren’t designed for mixing, only for connecting to external recording and playback devices, whether hardware (a USB microphone) or software (a softsynth).
You might be asking: “But aren’t output buses designed for mixing either? I don’t understand.” My answer: The plugin rack in output buses is designed for mixing. The output ports (including the faders) are not.
“But then what’s the point of buses having faders?” For example, for the Master bus, which is the one that connects to the outside. And for the others too, but for connecting to devices, not for mixing.
Imagine: You want to collaborate with a friend because he’s good at mixing and mastering. However, he works with a different DAW (we all know your friend has his quirks, but we love him just the same). You’ll need to freeze/render your groups and aux buses. That is, you’ll need to record your buses to an external device on separate tracks so they can be seamlessly imported into in your friend’s DAW. You might find the faders useful in this process for adjusting volumes and panning.
Other cases: Connecting specific buses to external devices for monitoring purposes. Etc., etc.
They’ve never lost their purpose. However, they’re not necessary for the mixing process.
“But do I need faders on the buses to mix!!!” Add gain and panning plugins. Those are your faders.
“Are you telling me I can’t use the bus outputs for mixing?” I’m not saying you can’t. I’m saying they weren’t designed for that purpose.
“What if I try to record the master output to a track to get my master copy?”
WARNING!!! Do not use Tracks / Export Tracks / Audio for this. As its name suggests, it is only valid for tracks (exporting the direct signal of the track through its Output Bus/Group). It ignores Aux Sends between buses. It will not work for export buses with auxiliary and/or mixing function.
Wow! I do it that way too, recording in the session itself. Indeed, the best way to create a copy (a render) of the “Final Master” is to record the session in real time. This applies to any DAW. It’s the only way to ensure that exactly what you hear is recorded…
But… it won’t work. It’s not an external device: As we’ve already said, these ports are designed to connect to external devices.
However, you can record your final Master in Qractor if :
Others prefer to use external recorders for this task: SoundRecorder, Cadence-Render, etc.
Although, recording in the session itself has advantages:
We’ll cover the mixing area in the next section.
The mixing area in Qtractor can be said to covers the tracks (including racks and faders) and the plugin racks for the buses.
Qtractor provides us with the following mixing tools:
Logically, each track’s output is connected to the bus that hosts it. Additionally, tracks and buses MIDI can also be joined to audio groups, as they can host softsynths with audio outputs. In this case, the output bus is assigned with right-click on the plugin rack: Audio > Bus to Select.
Aux Sends allow you to send signals from track to bus and from bus to bus. They are pseudo-plugins (internally predefined plugins). They are accessed by right-clicking on the plugin racks: Inserts > Audio > Add Aux Sends.
They have one limitation: They don’t allow connections between tracks. For sidechain connections and to simplify connections, it’s sometimes useful to interconnect tracks. Qtractor has never had a tool for this purpose.
In those cases, direct connections between pseudo-plugins Inserts (Inserts > Audio > Add Insert) could be used, which we’ll discuss below. However, this was never their intended purpose for Inserts, and it was always considered inadvisable to use them this way. Despite everything, since there was no other way, we used them. In fact, there are even “How to” guides on this wiki that describe their use to interconnect tracks.
Interconnect Inserts directly may work in Pipewire, but not in Jack2 or vice versa. Or maybe one, or the other, (or even Qtractor itself) has an update and stops working. They weren’t designed for that job. It’s that simple. This can mean that old sessions stop working and need to be rewired.
Fortunately, there are alternatives for this task today. Once again, the SEND and RETURN plugins in the LSP suite. In addition to simplifying these workflows, they work directly with other plugins in the same suite without the need to set up dedicated connections. Using “Inserts” to interconnect tracks no longer makes sense.
If “aux sends” are used to make dedicated internal connections to the mix, “inserts” are used to integrate external devices in the mix. That is, you can use external software devices (effects pedals like Rakarrack, etc.) and hardware devices (a compressor, etc.) in real time as if they were internal plugins.
If you directly connect one insert to another, you will create an internal connection, not an external one. Therefore, there’s no guarantee that it will work correctly.
You guessed right. Anything that involves connecting inserts to each other, buses to each other, or buses and inserts to each other may not work. This is not recommended. These elements were never designed to be interconnected, but rather to be connected to an external device.
This is precisely the solution. Specific situations may always arise where make these connections are useful: record parts of tracks on other tracks, obtain a copy of the final master, etc. Place an external device (input and output ports) between them. Don’t connect them directly.
You may be wondering: “How do I create an external device with audio inputs and outputs that allows me to create the bridge?”
pactl load-module module-null-sink sink_name=BRIDGE sink_properties=device.description="BRIDGE"This will create a virtual device with the external ports. The “sink_name” sets the semantic identifier of the device, and “sink_properties” sets the name visible in connections. Another advantage is that you can add this command to your linux “Automatic Application Startup Session”, so it will appear every time you login your computer. This allows you to save the interconnections in your Qtractor template.
Freedom above all.