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Tracktion Manual
Chapter 6 - Audio Devices
How do I choose which audio devices are used?
The settings screen (click the 'settings' tab at the top of the screen) has a category for 'audio devices', which lists all the audio devices available, and lets you enable/disable them and adjust their properties.
There are three categories - DirectSound devices, ASIO devices, and MIDI devices. Each device in the list is either marked as 'active' or 'disabled' - clicking on this button will toggle it.
Tracktion expects there to be a default audio output device, and (optionally) a default midi output device. The output devices that are active have a 'wave default' or 'midi default' button down the right-hand side of the screen, and it there is more than one possibilty, you can click these to choose the best device for your system.
The default device will be used for playing previews of wave files, playing CD audio, etc., and when a track's destination is set to be the 'default wave output' this is where that track's audio goes.
How do I change the sample rates and bit depths being used?
On the devices screen, when a device in the list is active, it can be clicked to select it. The device's property-panel will then show parameters for setting the sample rate, bit depth, etc., where appropriate.
What is latency and how does it affect playback performance?
One of the properties of an audio input or output device is its latency. This is the minimum time it takes for audio that the computer generates to make its way through the soundcard and into your ears.
Low latencies make the system more responsive, especially when playing soft-synthesisers using a live midi input, but also make it harder for the computer to keep up and make it more likely to glitch. Different soundcards will impose different limits on the latencies that are possible.
To experiment with latencies, select an audio input/output device on the devices screen, adjust its latency parameter, and then see how smoothly audio can be played back. It's probably a good idea to settle for the lowest value that doesn't produce any glitches during normal use.
To make very low latencies work properly it'll probably be necessary to turn on realtime priority mode.
What does realtime priority mode do?
This option will put Tracktion into 'realtime' mode, which means that it is allowed to use more of the computer's resources for playback. When using very small latencies, this can make a big difference, but when Tracktion starts using too much cpu, is can make the system a big clunky and unresponsive to the mouse.
This option is found on the 'audio devices' section of the settings screen.
How can I make sure audio recordings are correctly in-sync with playback?
Tracktion will attempt to make sure recordings are in-sync with the playback as far as possible, and for ASIO devices this is normally possible. With a lot of DirectSound drivers, however, the accuracy may vary by a few milliseconds.
If an audio input device is selected on the settings screen or the edit screen, one of its properties called 'time adjust' can be altered for manual sync adjustment. This is a time by which new recordings will be shifted to compensate for any other delays there might be in the signal chain. To automatically calculate a value for this setting by playing some test audio signals and measuring the delay for it to come back in, click the 'auto-detect' button and follow the instructions on-screen.
Where do newly recorded files go?
When an audio input device is selected on the devices screen (or the edit screen), amongst its properties is a directory in which new files should be created. Unless this parameter is explicitly set, it will default to be the directory containing the currently open project.
Also in these properties is a prefix from which new filenames are created, and the name of the next file that will be created, so that this can be explicitly set if required.
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