Self-hosted LAN-based driveway chorus rehearsal

Genre/use case:

When it got too cold for my mom’s vocal groups to hold COVID-safe outdoor rehearsals, we tried using JackTrip to allow her singers rehearse from my driveway, each in their own car with an Ethernet cable; it’s working even better than we’d hoped!

She calls it her “Car-Us” – and now has four groups of four or five singers, plus one group with 10 singers (as well as her piano & vocals); they all love it (now that the growing pains have been worked out!), so I thought I’d share the setup, in the hopes of helping anyone else with similar conditions, which are:

We’re in semi-rural Ohio, with Spectrum internet service; our closest JT Virtual Studio is in Columbus, which is about 60 miles (and, sadly, 40ms!) away. That latency was just too hard to work with, so I’ve been experimenting with a local self-hosted server for my band; I extended my household LAN to the garage, and then out to her singers’ cars.

Required gear:

  • A local JackTrip Virtual Studio server. We’re using a laptop running Ubuntu Studio (a version of Ubuntu Linux that’s optimized for low-latency/real-time audio, and comes with many audio/video/ tools preinstalled)
  • A local-area network. We’re using our WiFi router plus some cheap network switches, a spool of old Cat5e cable, and related cable ends, crimp tool, etc.
  • Some JT bridges. We have six of the Recommended Build devices (with the HifiBerry DAC+ADC Pro, which supplies mic power) – and have all we need except the Pi 4b boards to build six more . . . those are still of stock, unfortunately, with months of delay ahead!
  • Singers’ equipment. We’re using low-end but decent gaming headsets (with PC connections – separate plugs for the mic & headphone speakers) for $25; these plug directly into the JT devices (but were a bit quiet, so we added $6 headphone amps). In warmer weather, the singers use my band’s PA with the usual mics/XLR cables/speakers – and we tried using those in the cars at first; a dual-XLR-to-stereo-1/8" cable allowed two singers per JT, with a 1/8" stereo splitter plus amps for the headphones. That worked OK, but the extra cables & needing to hold the mic plus the sheet music made the headsets a better choice (except for the bigger group, due to our limited # of JTs).
  • Power. Instead of running separate power cables, we are using power inverters that plug into the cigarette-lighter/12VDC power outlets, with the high-power USB-C power supply plugged into those. It’s ugly, but I couldn’t find any 12VDC-to-5VDC converters (the high power car USB-C all seem to do some fancy voltage increase to get the rated high power, but the Pi needs actual high amperage @ 5V); I did look into some parts to do that conversion directly . . . but lack the time to build them. So off-the-shelf 12VDC → 120VAC → 5VDC it is!

On top of that, my mom plays keys in the house (one JT for her headset, and another for the keyboard, as stereo piano really makes a noticeable difference!)

Pictures, please!



If anyone is interested, let me know, and I’ll edit this (or comment?) to add links to all the equipment, and go into more detail.

This is wonderful! Please fill us in with all the details you desire to share. Pictures say a lot too! Thank you so much for sharing your experience. - Synthia

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This is extremely cool. While this sort of setup may not be as necessary in the near future, I am quite interested in how your Ubuntu Studio is setup. I love the idea of JackTrip, but I haven’t implemented it yet, partly because even nailing down basic audio settings in Ubuntu Studio has been a challenge for me. Please share!

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Just an FYI: the desktop version of JackTrip runs on OSX, Windows, and Linux.

Cheers

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Right. I am in the process of switching to Linux completely. Fingers crossed. But, this early hurdle is not completely resolved.

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Voice teacher and children’s choir director here. Bravo!

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I wish I could offer more help – but I (purposefully) did as little as possible to tweak Ubuntu Studio . . . so I didn’t write down much about what I did do (as I would have if I’d been changing more!)

If you have specific questions about settings, I’ll tell you what mine are set to (note that I won’t be very fast to respond, but I will eventually, as you see demonstrated here! :D)

Here’s what I recall:

  • I started with Studio 21.10 (wishing they’d made a special December release to honor my fave band, Rush! :D), accepting (pretty much?) all defaults
  • I tried the latest JT release, but something added (I forget what) in the GitHub nightly releases(?) sounded vital to what I was doing, so I ended up building & running that
  • Again, I tweaked the JT settings (build and run-time) as little as possible (to be easiest to reproduce); I wrote down a few things about that; will try to find them

The most important point is that it did end up working – don’t lose hope!

I certainly hope COVID declines to become unimportant – but that is not at all the primary reason for this; my little Ohio town (pop. ~3500) is building out the pilot phase of a municipal fiberoptic network . . . so the whole town will be able to sing (and play!) together virtually (instead of having to get together in person). We’re a very musical community, so it feels to me like this will continue and even grow.