4 ms·

Nah, low latency audio is absolutely possible, but not necessarily using pulse audio. Using either Jack for the low latency stuff has been the advice for years,

Nah, low latency audio is absolutely possible, but not necessarily using pulse audio. Using either Jack for the low latency stuff has been the advice for years, but with the advent of pipewire you can mix and match without too much difficulty. A quick skim didn't turn up what audio backend this project is using, but I'm using patchbox with modep on my Pi4 as a bass pedal board and it's pretty much flawless low latency. I do need to add a fan to my pi since it's mounted underneath a pedal board and doesn't get quite enough air though.

weberer 4y ago
Sep 2 of the build instructions says it requires RtAudio.
- jcelerier 4y ago
  RtAudio is just an API wrapper which calls JACK, Alsa, etc behind the scenes and does not add latency, just the overhead of a couple c++ method calls
- heinternets 4y ago
  what is the latency of a raspberry pi running this type of software? can't find figures anywhere
  - rerdavies 4y ago
    3.9ms measured audio latency using a loopback cable. https://rerdavies.github.io/pipedal/AudioLatency.html https://rerdavies.github.io/pipedal/AudioLatency.html
  - BizarroLand 4y ago
    I also wonder about the latency of the behringer interface. I've had one before, the sound quality is pretty good for entry level high-fi audio, but when I've run the audio into a DAW and back out post-processing there has always been an audible delay. Granted, this was in windows, but from what I understand there is always going to be some audible processing delay with a USB 2.0 interface.
tsegratis 4y ago
Wow, what fx are you running -- and does that or could that include convoluted reverb? (Convoluted reverb is utterly awesome but more processor intensive than almost anything else) Edit: and sorry, to be helpful, by low latency, could you meantion how many ms that is -- because while I'm very happy for you, and really interested, 15ms is very different to say 5ms or lower
- tcrenshaw 4y ago
  My normal chain is a noise gate, followed by a comp, a little emulated tube drive, an SVT amp model, an impulse response modeled cab simulator (of course running a 8x12 SVT cab), a plate reverb, and a limiter. I've got some crazier ones, but as a beginner bassist, that's all I really need. There are literally hundreds of effects to choose from though. Convolution reverb is an option, but it ended up being a little more than the Pi4 could handle iirc. I didn't tinker with it much though. Latency is under 10ms, I'd have to go back and check my settings to confirm exactly though.
  - tcrenshaw 4y ago
    Just double checked my jack settings; I'm running my interface at 48000hz with a buffer size of 128 and 2 periods for a theoretical latency of 5.33ms. I'm sure USB adds a fraction of a millisecond as well.
    - tsegratis 4y ago
      Thanks! Musically that's really viable and fun setup A really helpful data point :) -- You're doing great! You don't need my help, but just share my own path, because it's fun :) Yeah, play the bass, if i start talking about computing im not helping... Err, why am i still here? I switched to BSD or the OSS driver and went from massive effort ~5ms to zero effort ~2ms Then I made a two button controller and pedal->usb, and started programming an arbitrary effects controller: a looper + buttons to switch the pedal to control any fx parameter Fun, but it didn't help me make better music :)
    - rerdavies 4y ago

weberer 4y ago

Sep 2 of the build instructions says it requires RtAudio.

jcelerier 4y ago
RtAudio is just an API wrapper which calls JACK, Alsa, etc behind the scenes and does not add latency, just the overhead of a couple c++ method calls
heinternets 4y ago
what is the latency of a raspberry pi running this type of software? can't find figures anywhere
- rerdavies 4y ago
  3.9ms measured audio latency using a loopback cable. https://rerdavies.github.io/pipedal/AudioLatency.html https://rerdavies.github.io/pipedal/AudioLatency.html
- BizarroLand 4y ago
  I also wonder about the latency of the behringer interface. I've had one before, the sound quality is pretty good for entry level high-fi audio, but when I've run the audio into a DAW and back out post-processing there has always been an audible delay. Granted, this was in windows, but from what I understand there is always going to be some audible processing delay with a USB 2.0 interface.

tsegratis 4y ago

Wow, what fx are you running -- and does that or could that include convoluted reverb? (Convoluted reverb is utterly awesome but more processor intensive than almost anything else) Edit: and sorry, to be helpful, by low latency, could you meantion how many ms that is -- because while I'm very happy for you, and really interested, 15ms is very different to say 5ms or lower

tcrenshaw 4y ago
My normal chain is a noise gate, followed by a comp, a little emulated tube drive, an SVT amp model, an impulse response modeled cab simulator (of course running a 8x12 SVT cab), a plate reverb, and a limiter. I've got some crazier ones, but as a beginner bassist, that's all I really need. There are literally hundreds of effects to choose from though. Convolution reverb is an option, but it ended up being a little more than the Pi4 could handle iirc. I didn't tinker with it much though. Latency is under 10ms, I'd have to go back and check my settings to confirm exactly though.
- tcrenshaw 4y ago
  Just double checked my jack settings; I'm running my interface at 48000hz with a buffer size of 128 and 2 periods for a theoretical latency of 5.33ms. I'm sure USB adds a fraction of a millisecond as well.
  - tsegratis 4y ago
    Thanks! Musically that's really viable and fun setup A really helpful data point :) -- You're doing great! You don't need my help, but just share my own path, because it's fun :) Yeah, play the bass, if i start talking about computing im not helping... Err, why am i still here? I switched to BSD or the OSS driver and went from massive effort ~5ms to zero effort ~2ms Then I made a two button controller and pedal->usb, and started programming an arbitrary effects controller: a looper + buttons to switch the pedal to control any fx parameter Fun, but it didn't help me make better music :)
  - rerdavies 4y ago