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wiki:cadence_introduction [2013/10/22 15:20] – [System Status] danboid | wiki:cadence_introduction [2013/10/22 15:45] – [JACK Bridges] danboid | ||
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=====System Checks===== | =====System Checks===== | ||
- | Current kernel is a verification that you're running a realtime or lowlatency kernel. This check will be ticked already if you installed from the KXStudio ISO as it includes a low latency kernel. The other check verifies that your user is included in the audio group. Being a member of the audio group is required for your user to run JACK in realtime mode for optimal performance. You can add your user to the audio group by running: | + | Current kernel is a verification that you're running a realtime or lowlatency kernel. This check will be ticked already if you installed from the KXStudio ISO as it includes a low latency kernel. The other check verifies that your user is included in the audio group. Being a member of the audio group is required for your user to run JACK in realtime mode for optimal performance |
+ | |||
+ | The user created during installation of KXStudio 12.04.3 is automatically added into the audio and video groups but newly created users will not be part of these groups. You can add a user to the audio group by running: | ||
sudo adduser < | sudo adduser < | ||
- | Replace < | + | Replace < |
=====JACK Status===== | =====JACK Status===== | ||
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**DSP Load** is the current CPU load estimated by JACK. If it gets too high you may experience performance issues. | **DSP Load** is the current CPU load estimated by JACK. If it gets too high you may experience performance issues. | ||
- | **Xruns** For JACK to operate smoothly and without drop-outs it requires that its buffers (the memory used to transport audio) provide a continuous stream of data. Whenever this data fails to arrive in time to satisfy the requests of a JACK app it causes an xrun which is often accompanied by a disruption to the sound output. The key to success with JACK is to eliminate or avoid xruns. | + | **Xruns** For JACK to operate smoothly and without drop-outs it requires that its buffers (the memory used to transport audio) provide a continuous stream of data. Whenever this data fails to arrive in time to satisfy the requests of a JACK app it causes an xrun which is often accompanied by a disruption to the sound output. The key to success with JACK is to eliminate |
- | **Buffer** size is measured in frames per second. It determines the latency between the audio being received by JACK and being sent to the output device. The smaller the buffer the lower the latency and, as a result, the higher the accuracy when monitoring audio for multitrack recording. 1024 is the default and is usually a safe value but smaller buffer sizes have less latency, i.e. less delay between the input and output. Try different settings to see how low you can go when recording without getting xruns. The functioning of lower size buffers depends on the power of your CPU and the specifics of your audio device. The lowest buffer most devices can handle well is 64. | + | **Buffer** size is measured in frames per second. It determines the latency between the audio being received by JACK and being sent to the output device. The smaller the buffer the lower the latency and, as a result, the higher the accuracy when monitoring audio for multitrack recording. 1024 is the default and is usually a safe value but smaller buffer sizes have less latency, i.e. less delay between the input and output. Try different settings to see how low you can go when recording without getting xruns. The functioning of lower size buffers depends on the power of your CPU and the specifics of your audio device. The lowest buffer |
- | **Sample rate** is the frequency JACK will run and record audio at. 44.1kHz is the CD audio standard, but 48kHz is more common to go with video or for other typical audio. Higher sample rates allow for higher quality but take more disk space. Even for professional purposes, 48kHz is usually fine as the default. | + | **Sample rate** is the frequency JACK will run and record audio at. 44.1kHz is the CD audio standard, but 48kHz is more common to go with video or for other typical audio. Higher sample rates allow for higher quality but require |
**Latency** is the JACK capture latency which measures the time taken to fill the audio capture buffer. This value is determined by the buffer, period size and samplerate settings used to start JACK. | **Latency** is the JACK capture latency which measures the time taken to fill the audio capture buffer. This value is determined by the buffer, period size and samplerate settings used to start JACK. | ||
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The ALSA MIDI bridge needs to be running if you want to use any MIDI hardware. | The ALSA MIDI bridge needs to be running if you want to use any MIDI hardware. | ||
- | PulseAudio is not included by default with KXStudio, and so the PulseAudio bridge will not function | + | PulseAudio is not included by default with KXStudio and so the PulseAudio bridge will not function |