How to Use the Command 'pasuspender' (with Examples)

pasuspender is a command-line utility that temporarily suspends the PulseAudio sound server, allowing another command or program that requires direct access to audio hardware to run and fully utilize ALSA (Advanced Linux Sound Architecture) instead. This feature is particularly useful for audio applications that demand low latency or need to bypass PulseAudio’s sound control processes. PulseAudio, while versatile, introduces latency and other processing overheads that can interfere with certain professional audio workflows, making pasuspender an invaluable tool for audio engineers and enthusiasts who require optimal performance from their audio software.

Use Case: Suspend PulseAudio While Running jackd

Code:

pasuspender -- jackd -d alsa --device hw:0

Motivation:

The motivation for using this command lies in the requirements of audio professionals and enthusiasts who need to run the JACK Audio Connection Kit (jackd) with the ALSA backend. JACK is an audio server known for its ability to handle audio in real-time, offering low latency and high-quality sound processing. However, JACK often runs into compatibility issues with PulseAudio, as both try to control the sound hardware. By suspending PulseAudio temporarily, pasuspender ensures that jackd can operate without interruptions or resource conflicts, allowing smooth audio processing essential for tasks like mixing, recording, or live performing.

Explanation:

• pasuspender: This is the utility that handles the temporary suspension of PulseAudio. It allows another program to access the audio hardware directly by releasing control of the resources typically managed by PulseAudio.
• --: This argument tells pasuspender to treat everything that follows as the command that should be run while PulseAudio is suspended.
• jackd: This is the JACK Audio Connection Kit server, which manages real-time audio processing tasks.
• -d alsa: This parameter specifies that JACK should utilize the ALSA driver backend. ALSA communicates directly with the kernel sound system, offering better performance for audio tasks than when going through PulseAudio.
• --device hw:0: This argument specifies the ALSA hardware device to use. hw:0 indicates the first sound card detected by ALSA, which is typically the primary sound device on the system.

Example Output:

When this command is executed, you may not see verbose output directly from pasuspender, but rather from jackd as it starts. The output might look something like this:

JACK server starting in realtime mode with priority 10
audio_reservation_init
Acquire audio card Audio-0
Creating ALSA driver ... 
hw:0|hw:0|128|2|48000|0|0|nomon|swmeter|-|32bit
configuring for 48000Hz, period = 128 frames (2.7 ms), buffer = 2 periods
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 2 periods for playback

This output confirms that JACK has successfully taken control of the audio device using ALSA, and PulseAudio has been suspended for the duration identified by jackd’s operation.

Conclusion

The pasuspender command is an indispensable tool for managing audio resources on systems where both PulseAudio and ALSA are employed, especially in environments demanding real-time audio processing. By understanding how to effectively use pasuspender, audio professionals can ensure seamless operation of applications like JACK, leading to improved audio performance and reduced latency for critical audio workflows.