The master faders process the main mix after every track and aux return has been
summed, so a lookahead insert on them (the Maximizer: 71 samples at 48 kHz)
delays the whole main mix. The mix's compensation latency, which a bounce drops
from the head of the render, left it out, so the bounce came out late by the
insert's latency (the voice was 71 samples later than in the same mix without
the Maximizer).
The latency of the master inserts is now part of the mix latency. With Delay
Compensation off nothing changes.
render_bus dropped only the track-insert latency from a bus, but an aux that
returns onto a bus delays it by the slowest aux return as well. With Delay
Compensation on, a bounce of such a bus came out late (a 5 ms lookahead left
240 leading silent frames) and its last impulse fell outside the requested end.
The engine now knows which busses an aux returns onto. A bounce of one drops
the aux latency too, and the tracks routed straight to that bus wait for it, as
the tracks routed to the main mix already do, so the two kinds of signal on the
bus arrive together. Other busses and the main mix are unchanged.
