FAQ omits latency added by api.alsa.disable-batch and api.alsa.headroom
The wiki FAQ section about latency does not mention that
api.alsa.headroom add latency compared to using ALSA directly (or JACK in synchronous mode). I have done some experiments measuring roundtrip latency with Mixxx using the PortAudio JACK backend to connect to PipeWire and found that setting
api.alsa.headroom = 0 reduced the latency by about 1 ms and
api.alsa.disable-batch = true reduced the latency by about 22 ms. The additional latency seemed to be unrelated to the buffer size in my testing.
I am questioning if PipeWire should add any latency by default. I have not yet experimented much to determine whether there is more glitching with those options disabled. Regardless, the FAQ should mention that users should uncomment these lines in
alsa-monitor.conf if they want minimum latency.