Reducing audio latency - some echo measurements with oscilloscope

General Discussion
18

Just a few more take-aways as I’ve been reflecting more on this topic:

  • Always use buffer sizes of 64 when you can. This perhaps has the biggest impact overall and is also mentioned in our guide on optimizing latency. It raises the question, “why does JackTrip default to 128?” This is a question that I still struggle with myself. Lower buffer sizes require faster CPUs, and many computers and audio interfaces can’t handle it. Some even have trouble with 128. So it’s mainly a matter of trying to balance how many people we have complain that it doesn’t work (bad audio) versus latency optimization. To put things in context though, 1024 would have been the number not 10 years ago, and I could see it being 32 or 16 10 years from now… with time everything will get faster, and all of this will get easier.
  • Your audio interface’s round-trip latency is perhaps the most significant single metric, other than the Internet round-trip measurements already provided by JackTrip. After going through measuring all these things that slow/hard way, I (re-)discovered this RTL Utility, which maybe we should just settle on as the go-to for measurement. I do think it’s helpful to have other methods used to compare and verify it, though, which I’ll be doing with my previous results to gain more confidence.
  • Low-latency audio isn’t unique to JackTrip, and many other efforts have focused on this over the years, including measuring many different audio interfaces. Perhaps the most popular is DAW Bench. This seems to be far from complete, however, and focuses more on the high end use for DAWs. There are many thousands of audio interfaces out there, all of which deserve independent measurements. It’s a shame that most manufacturers don’t do this themselves and report it in specifications. But considering the massive differences, I can understand why.
  • I hesitate creating yet another effort to measure audio interfaces when so much has been done already, but I also haven’t found a comprehensive, open and crowd sourced database that I feel is required. Perhaps others know of more resources out there?