C3 + ReaStream = a whole lot of joy

I had a play with streaming audio over a network and was amazed how well it worked.

I wanted to use an ageing Q6600 based pc (source) to generate audio and send it my main laptop (destination).
On the source I set C3 to use its null audio driver so that pc didn’t even need to have a soundcard.
I then routed the audio using the free ReaStream vst from Cockos.
I ran another instance of C3 with the Reastream vst on the destination machine.
Configuration was nothing more than setting the ips in both instances of ReaStream and ensuring the firewall didn’t get in the way.

I could run the null driver on the source at 64 samples with decent performance, and very decently when set to 128 samples. The network layer added a minimal latency (I was using an inexpensive TP-Link gigabit switch).
In practical terms, it was extremely playable and entirely robust.

I had a MIDI keyboard connected to the source but ReaStream also supports MIDI (and multchannel audio). So the next test is to use the destination laptop to generate the MIDI that the source will use to generate the audio (being careful to avoid feedback).

Before trying ReaStream I was mucking around with Voicemeeter Banana’s VBAN which provides a more general network audio service. I had to use ASIO for all along with another instance of a virtual audio driver. So altogether more fiddly and slightly lower performance.

@brad, could you possibly confirm the licensing implications here? If for personal use then 2 instances of C3 running simultaneously is OK? If another person uses the 2nd machine that will need another license?

Again, another example of C3 (and Cockos) providing a high-performance, elegant and robust solution to a problem you didn’t even know you had.


I use WormHole for that, it gives every vst an own audiochannel, for use in the DAW on my main machine.
For C3 I use a dedicated machine for key’s.

@TheVork, I did look at wormhole2 but it seemed it didn’t have a 64bit version. Does it have one?

Nope, but it works fine. On C3 I use Jbridge and the Sonar has an intern bridge for 32bit.

This approach is all new to me. Are you suggesting we could place a particularly CPU-heavy VST onto a different computer so it has that computer all to itself, sending it MIDI from the main Cantabile machine and incorporating the audio from the CPU-heavy VST into our Cantabile session with little latency?

If I could bring the livingroom computer into play with the studio one, I’d be pretty thrilled!

Definitely following this thread!


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Yep, audio and/or midi, I use it for audio.
One machine for the VST with C3, every instrument sends its audio output to the wormhole vst (every instrument has is own wormhole vst).
On the DAW there are audiotracks with a wormhole vst, as many as needed.
The set up is very simple.

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@terrybritton, yeah I just did the test with ReaStream sending MIDI from machine a to machine b. b generates audio and streams in to machine a. It works very well.

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And of course the logical conclusion is to use this technique with pizMIDI’s midiPolyphony, UHE’s Repro-1 and a couple of / few decent machines to make a Prophet 10 or 20 or 30.


I’d love to know what the round trip latency is for MIDI from A to B then audio back from B to A. Perhaps by generating audio on A too, and recording and comparing waveforms on both audio streams…


@Neil_Durant, will get some figures to you asap. I’m out of town atm, should be back in a couple of days.

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For me, latency is not realy a problem, because I record track by track.
However, the latency with wormhole is, if the buffersize is right ;-), not a problem.
Maybe because I use dedicated machines and network? :slight_smile:

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See here.

TL;DR: this kind of setup requires two licenses.

@Neil_Durant, here’re some quick results.
System A running C3 lite, 64 sample buffer to null audio driver. 44.1khz
System B running C3 performer 96 buffer, Babyface pro usb device. 44.1khz
A audio was panned left, B audio right. Stereo recorded. Zebra 2 playing a snare sound on both systems.
I disconnected other devices from the switch, which made a difference)

MIDI A to B, audio B to A. Returned audio is 16-17ms delayed
MIDI generated on A and B simultaneously (sent from different ports on DMC-122). Returned audio is 7-8ms delayed.


@brad, I understand your need to for balance in the license. It does feel a bit restrictive given it’s for single person use. By using C3 Lite on a satellite machine is presume I’m meeting the requirements for a 2nd license?

Thanks, that’s really useful and interesting. So probably a bit too much latency to, for example, farm out some heavy plugins to a second “slave” machine for use live. But great for many other purposes.

Thanks for the info!


Yep, you can run as many Lite’s as you like.

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I am trying to understand the advantage for live gigs with this set up. I have a 4th gen i7, 16gb ram and two SSDs in my laptop running to a UR28M I absolutely love the incredible diversity of the UR28M, and multiple gain options combined with line level instrument passthrough gain control.

I too have a pretty powerful rig. I’d sooner keep the cpu load to one capable machine rather than farm it out.
However, if a band member was going to moonlight and play some extra keys then this tech will give you options.
All they’d need is a usb keyboard and a laptop with a network port. They don’t need a fancy soundcard because they can use your super-sweet dac and you don’t need any spare digital inputs to receive their digital audio. If they are going to play your instruments they don’t need a MIDI interface to send you MIDI and you don’t need any additional MIDI inputs or usb sockets.

Ahh!! I get it. That sounds cool. How much is the program to facilitate network sharing?

It is free (as in beer).
You can run C3 lite (or any other vst host) on the satellite systems and the ReaStream vst is available as part of the free ReaPlugs package from Cockos, the team behind the DAW, Reaper.

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