Reply To: Configure mix server to send own signal back?


You can delay your own signal by using the “N sample buffers of self delay” below the volume slider in the left coloumn. Unfortunately you need to experiment a bit to find the correct number of buffers. You can try a mirror and adjust your own signal to the mirror so that it sounds tight.
Remember the network delay to the mirror as shown at the right of the mirror connection as well as the number of buffers for the self delay. Then make a connection to your mix server. The buffer delay can easily computed by the following formula: buffer delay in milliseconds is 1000 * sample_buffer_size / sampling_rate.
So for a 64 sample buffer this is 64000 / 48000 = 1.33 ms, for 128 samples 2.67 ms and for 256 samples per buffer 5.34 ms.
For example: if the network delay difference between mirror and mix server is 6 ms (mix server is quicker) and you use a sample buffer of 64, then you need to reduce the number of self delay buffers by 4 (5.34 ms) or 5 (6.67 ms).

BUT, you would get less delay if you make peer-to-peer connections. In that case you may need to forward the UDP port 50050 in all of the routers used by the participants to your individual local SoundJack-computers and connect to everyone else to hear everyone, but for a rhythmical oriented music this should give you much better results.

For electric instruments the self delay works more or less well. You need to adjust to playing in advance, but since you only hear the delayed sound of your instrument, that is not too hard to do. For an acoustic drummer, singer or wind instrument that is much harder because they hear the acoustic sound undelayed and isolation from the acoustically radiated sound is almost impossible.
It might be best to define the drummer as the time kepper (metronome) and all other have to adjust to his play. The drummer needs to ignore the late sound from the others or all others need to double the numbers of self delay (playing in advance of the drummer in their headphones) so that the drummer hears all members together. But that can lead to a very large paying ahead. You might need to make a compromise. But with a faster peer-to-peer connection (which should be possible with five participants) this problem is halved by itself.

I think a server is only useful for slower reacting ensembles like choirs. Alex does not recommend to use a server at all because of the doubled network delay.

Keep in mind that the diplayed delay is the network delay only. Depending on the operating system, driver/interface and sample buffer size you can add about 8 to 25 ms for the I/O delay on both sides together. So it can get very hard to impossible to keep the network + i/o delay under 20 ms. Any possibility to reduce the delay should be used as long as the computers are fast enough (ideally having more than 2 processor kernels) to receive and send without too many dropouts.

Good luck!