Devices Preferences

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Geräteeinstellungen Preferencias de dispositivos

Gale 27Feb13: WASAPI and WDM-KS text Is a direct copy of Device Toolbar but then it was before.
  • Peter 21May15: WDM-KS host will not be in 2.1.1
Accessed by: Edit > Preferences > Devices    (on a Mac Audacity > Preferences > Devices)
Playback PreferencesRecording PreferencesQuality PreferencesInterface PreferencesTracks PreferencesImport/Export PreferencesExtended Import PreferencesProjects PreferencesLibraries PreferencesSpectrograms PreferencesDirectories PreferencesWarnings PreferencesEffects PreferencesKeyboard PreferencesMouse PreferencesModules PreferencesImage of Devices Preferences showing default settings for Host and Channels
Devices Preferences (shows default settings for Host and Channels).
Click on any other Preferences sections in the above image to read about those Preferences.

Interface

Peter 12Feb15: full WASAPI support is to be left turned on for 2.1.0

Please review.

  • Gale 20Feb15: Made minor changes and removed the P2.

Selects the particular interface with which Audacity communicates with your chosen playback and recording devices.

On Windows, the choice is between the following audio interfaces:

  • MME: This is the Audacity default and the most compatible with all audio devices.
  • Windows DirectSound: This is more recent than MME with potentially less latency.
  • Windows WASAPI: This host only appears on Windows Vista, Windows 7 and Windows 8. It is the most recent Windows interface between applications (such as Audacity) and the soundcard driver. WASAPI was first officially released in 2007 in Windows Vista. WASAPI is particularly useful for "loopback" recording of computer playback. 24-bit recording devices are supported using this host. Playback is usually emulated. As a result, the playback slider in Mixer Toolbar will only scale the system playback slider's current level up or down rather than directly manipulating that system slider.
Peter 29Jan15: Commenting this out as WDM-KS will not be included in 2.1.1.

ToDo-2P will need to restore this if and when WDM-KS support is added back to Audacity.

  • Windows WDM-KS: "KS" stands for "kernel streaming" which achieves low latency through bypassing the kernel mixer that is normally used to mix outputs from multiple applications. You may be able to achieve latencies as low as 5 milliseconds by reducing Audio to buffer in Recording Preferences until the sound breaks up, then slightly increase the buffer. When recording overdubs at such low latencies, you'll need to either set the default latency correction in Recording Preferences to zero, or take our Latency Test to set the optimal correction value. 24-bit recording is supported.

    Under WDM-KS, only one application is allowed to access the audio device at a time. So for example if you are already playing audio in the browser or another application, you will not be able to play audio in Audacity using the same device that the other application is using.

On Mac OS X the only choice is Core Audio.

On Linux there is often only one option: ALSA. Other options could be OSS and/or Jack Audio Connection Kit (also known as "Jack" or "Jackd").

  • On Windows XP (given a recent computer), DirectSound's much shorter path to the hardware should produce much lower latency than MME.
  • On Windows Vista, Windows 7 and Windows 8:
    • Windows DirectSound may by default have only slightly lower latency than MME.
    • Selecting Windows DirectSound or Windows WASAPI and enabling both "Exclusive Mode" boxes in Windows Sound allows Audacity to request audio direct from the device without resampling.
Peter 29Jan15: Commenting this out as WDM-KS will not be included in 2.1.1.

ToDo-2P will need to restore this if and when WDM-KS aupport is added back to Audacity.

  • On Windows XP (given a recent computer), WDM-KS's and DirectSound's much shorter path to the hardware should produce much lower latency than MME.
  • On Windows Vista, Windows 7 and Windows 8:
    • Windows DirectSound and WDM-KS may by default have only slightly lower latency than MME. However WDM-KS can produce latencies as low as 5 milliseconds if you reduce "Audio to buffer" in Recording Preferences as described above.
    • Selecting Windows DirectSound or Windows WASAPI and enabling both "Exclusive Mode" boxes in Windows Sound allows Audacity to request audio direct from the device without resampling.
    • When using WDM-KS, the currently playing application has exclusive access to the audio device irrespective of Windows "Exclusive Mode" settings. See the Wiki page for Windows 7 for more explanation.

Playback

  • Device: Selects the device used for playback.

Recording

  • Device: Selects the device used for recording.
On Windows, each entry for recording device consists of the input type (such as microphone), followed by the name of the audio device the input belongs to. If you have multiple audio devices, the list will be grouped so that inputs of each device are grouped together. The input level of the selected device can be adjusted in Mixer Toolbar, but device selection is no longer made there.
  • Channels: 1 (Mono), 2 (Stereo) or the number of channels that are provided by the drivers of your sound device. On most inbuilt sound devices, especially on Windows, only mono or stereo will be available. For some devices on Windows, choosing Windows DirectSound in "Host" above may be more likely to reveal options for recording more than two channels. On some devices capable of recording more than two channels, an explicit "multi" device may appear in the "Device" dropdown for recording all the channels simultaneously.
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