Nudging by offset

[niko123456 (Nicho)]

Hi… long time Ardour user returning after a very long break.

First time using USB hardware.

I have calibrated the interface using Ardour. Input and output latency is at 272 samples.

When I record a track… do I then need to nudge the recording by this offset? Or does Ardour take care of this automatically?

[Sahaathyva]

Hi,

I think Ardour compensate this latency, but with usb audio sound devices you must calibrate this thing everytime you launch ardour.

[x42 (Robin Gareus)]

see also

Hardware latency not constant?

Problem: I have measured hardware latency using the Ardour6 “Audio/MIDI Setup” dialog multiple times (once per day or so) and I got differing results (differs about 12ms=600 samples). That means that after the calibration, latency compensation works perfect, but when hardware latency changes, the old correction values are wrong and my recordings are out of sync. At the moment I cannot reliably reproduce the problem; it just happens from time to time. I thought hardware latency is (roughly) con…

[niko123456 (Nicho)]

Ahhh thankyou.

So the correct order of operations is (if you plan to record something):

• Measure and calibrate latency
• Do nothing

What about internally routed sources? Ie., another jack application patched to Ardour? Do I need to nudge in that case or will Ardour take care?

[x42 (Robin Gareus)]

@niko123456

So the correct order of operations is (if you plan to record something):

• Measure and calibrate latency
• Do nothing

correct.

Except with JACK there’s a problem… jackd has to be restarted in order to pick up newly measured systemic-latency. In case of USB-devices restarting JACK may change the systemic-latency (Ardour’s own ALSA audio-system does not have this issue).

Some users settle for some average, or simply use a small buffersize to work-around this jack issue.

Internal connections in Ardour are correctly compensated for. Other JACK apps are aligned if they report latency (many do, most also don’t introduce any latency). You can check with jack_lsp -l to list jack port latencies.