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Comment by shams93 | Hacker News Reader

I'm super excited as well. I figured out the secret sauce to get a low latency kernel build I was able to get down to 20ms latency but I'm excited to see if this can't get down to 10ms even though 20ms is acceptable low audio latency, already with only 1 gig of ram on a pi3 ardour is usable for multitrack recording, excited to see how this does with 4 gigs.

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Do you have a write-up on what you did to achieve that low of a latency?

I recently connected a midi keyboard to our Pi3 and ran Timidity for synthesis. It worked, but unfortunately the notes happen about half a second after you press a key, making it rather useless. Strange, since if you dump the midi events themselves to the console they appear to happen immediately.

I tried teaking alsa and pulseaudio settings, no luck. Also installed jack but never got sound from it. Eight hours on the weekend wasted with nothing to show for it. Any ideas on how to fix this?

I installed a low-latency kernel on my desktop machine with a midi keyboard over USB, got horrible performance until I got off of Pulseaudio.

I had some difficulty with Jack, but Alsa worked great. The main thing is you can't run Alsa and Jack at the same time. Once I was no longer using Pulseaudio, a lot of my problems went away -- I think it's just a really slow interface.

I mostly worked off of http://www.tedfelix.com/linux/linux-midi.html

Thanks. I got the feeling there was some buffering happening somewhere, but couldn't turn it off. Wonder how much applies to Rasbian.

I would also love to see a writeup about low-latency kernels on the Pi, if you've got the time.

Just recently got into audio processing, and I'm finding this stuff really interesting.

I played around with some Linux DAW stuff back in the day. That's awesome that you can achieve enough performance on an RPi these days.

I'm going to fourth the below suggestion. I'd love to see some more about how you achieved this.

Forgive me, but isn't 20ms kind of a lot of latency? That's more than a frame at 60hz. I assume I'm missing some context here.

In audio that's still acceptable. In our games we usually run at either 40ms or 60ms audio frame size(which means you are getting at least that much latency before hearing the sound for your action).

Fair enough, but I got the impression the parent was really trying to push the envelope here, so "acceptable" seems a far cry from that goal.