Audio distortion

HI folks. My band tested out JackTrip last night and we found that we could hear each other but the audio quality was inconsistent - it went from clear to distorted/robotic randomly. Can anyone help troubleshoot? Could this be a problem with latency? The timing of the audio didn’t seem to be the problem, it was the quality.

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Welcome @marc ! Thanks for posting your inquiry here. Most likely this is a sample rate mismatch. Make sure everyone is running at 48 khz sample rate, or at least the same sample rate.

It is hard to know for sure without more information about your equipment and settings.

Good luck and let us know your questions and progress.

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A sample rate mismatch would cause a consistent pitch shift, not periodic robotic sound. That is normally caused by Internet connection problems, in particular using Wifi instead of Ethernet. First thing to check is your latency indicators to see if someone’s connection is having trouble. There is also a “network outage” indicator displayed in the bottom left of your window, whenever your connection drops out. When using Wifi (or any wireless technologies), this will happen frequently, and causes lots of audio distortion like robotic sounds.

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Thanks to you both. I connect to my router with ethernet and my latency indicator fluctuates between Excellent (6-8ms) and Unstable - perhaps I am the problem? Is there a way to debug further?

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Yes, “Unstable” means that your network connection is dropping out and this will definitely cause audio distortion problems.

The good news perhaps is that it should be easy for you to reproduce this problem by performing a “network ping.” I usually use Google’s servers with the IP address “8.8.8.8”. If you search for “network ping” you’ll find more information on how to do this. If you’re familiar with the terminal on your computer, just typing “ping 8.8.8.8” should do the trick.

A few things you may want to try:

  • Make sure that you have wifi disabled. Oftentimes, your computer may be using wifi even when you have ethernet plugged in.
  • Try restarting your router, and any other networking devices that you have.
  • If you’re still seeing dropouts, contact your Internet service provider. They may send a technician out to check the cabling going into your home. There could be a bad wire connection or something else at play.
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That latency indicator sounds like WIFI behavior. Make sure that WIFI is
disabled and see if that helps.

Is anyone connected to the server using WIFI? Did everyone hear the
robotic sound or just you?

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Thanks again to both of you.

Ping: I ran the ping command in the terminal and.watched it for around 1 minute. It’s mostly the same at around 14ms but there are 2 entries of 175ms and 137ms and a few around 20ms. Does that indicate instability?

Wifi: My computer does not have a wifi card and my OS indicates that it has a “wired connection”.

Other users: The other users on the server have wired connections and also experienced the robotic audio. Oddly enough, we did a couple of 2-person tests and had better results - there was some distortion but not 90% of the time as we experienced when the 3 of us tried it together.

Wiring: I dread contacting my ISP to look at the wiring since I have an older home with unusual renovations. I’ve had technicians come and scratch their heads looking at it. This is absolutely a last resort for me unfortunately.

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how about creating a different server in a different location?

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When creating a studio it asks for the studio location and the city that all 3 of us live in (Montreal Quebec Canada) is one of the choices so we chose that. If we were to try another location what would you suggest?

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any other location would be fine to rule out a potential problem with
the server in Montreal.

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Yes, seeing 1-second pings jumping into the hundreds of milliseconds is a clear sign of network instability.

I realized after sending my last message that ping typically defaults to once per second, which is naturally going to have an infrequent rate of occurrence. At 48khz and a buffer size of 128, JackTrip is sending 375 audio packets to you every second. If you set the interval to something like 0.1 seconds, it’s still only 10 packets per second, but that would be more likely to reproduce the problem more frequently.

JackTrip reports network instability when it detects a network outage lasting 30ms or more, which is long enough that it’s impossible to recover the audio that was lost. There is unfortunately nothing that we or anyone else can do about it other than suggesting that you bump up your buffer sizes, which will dramatically increase your latency (this is how Zoom and everything else works, which is why you wouldn’t hear it elsewhere).

I won’t throw anyone under the bus, but we have encountered ISPs with faulty backbone network routers that cause instability for entire geographical areas. Having worked in the field for decades, I know this is unfortunately quite common. A lot of the times it turns out to just be a bad cable or something, but sometimes their equipment is just over-provisioned. This is more likely to happen on old coax (cable) internet connections, where everything in an area is shared. Something as simple as your neighbor watching a movie on Netflix can cause your connection to flake out.

I know you probably want to hear it as much as I want to say it, but if you require flawless, low-latency audio, your only option may be switching to a fiber internet connection, or waiting for it to become available in your area (if not already).

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are you guys still jacktripping? what worked? what still doesn’t work? would love to hear more about your experience - good and not so much.

also wanted to share there is a jacktrip drummer in Montreal who plays a full kit in case you are interested - here are a couple of his posts: https://www.facebook.com/groups/1234010610292945/user/583356931
https://www.facebook.com/photo?fbid=10159447815231932&set=gm.2111609555866375&idorvanity=1234010610292945

Hi Synthia. We never got it working satisfactorily (poor audio quality).

ah, but wait, do you mean connection quality? Because audio quality has
a lot to do with tweaking user settings and other software in use. If
the internet connection is stable, there is a lot that can be done with
audio.

One thing you could try is “Broadcast Mode”, which sends a separate
mixdown to listeners where latency is not an issue, while only the
performers will hear the noisy-er audio. If you ever feel like
experimenting I would be happy to jump on with you.

Take good care!

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It was just 3 of us trying to jam together, no audience. We tried tweaking a million things but always ended up with distorted audio or dropouts. I believe the problem was simply no-good-enough internet connections.

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Ok sorry to hear that the internet connections were unstable. Network technologies are getting better so maybe you’ll try again sometime.

Thanks for your interest.

One last thought after remembering that we recently had a trouble ticket on someone whose external audio interface was stuck on 16 for the buffer size. For most users that is too low and usually no less than 64.

Are you all using the computer onboard mic and output or external?

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We tried onboard and external cards and messing with the different buffer sizes, nothing helped.

Well you definitely put in the effort! Thanks for sharing.