Lines and Valves
A run of Vibrating Rods (infrasound) or Waveguides (ultrasound) is a line. Sources touching it add up if they play the same tone; two different tones on one line are a dissonance and nothing flows. A machine touching the line takes its tone and power from it.
At every junction the power is split equally between the ways on (a machine there counts as one); what a branch does not need goes to the others. A Sound Valve goes round a pipe already in place: click to open or close it, a redstone signal closes it too, sneak-click takes it off. A closed valve cuts its branch off, so the power is not split towards it. Point a Wave Detector at a pipe to read its line.
Gears: a line’s tone works like speed. Each band has three: infrasound 1–6 Hz slow, 7–12 normal, 13–19 fast; ultrasound 20–45 kHz slow, 46–70 normal, 71–100 fast. Slow: half the pace for half the power; fast: twice the pace for 2.5× the power. Machines on lines are not tuned: what they do is chosen on their screens. Some recipes need a line of at least so many kilohertz.