š¢ Before use: turn phone volume to maximum, disable Silent
mode (ring/action button), and keep this page in the foreground. Prop the
phone at a fixed, marked distance from the EV mic so tests repeat.
Source
Level
80%
Mode
Ready.
Continuous ā steady source while you set the mixer or turn the SENS
trimmer. Burst + stopwatch ā plays the source for the chosen time,
then goes hard-silent and counts up, so you can time how long the room must
stay quiet before playback returns (the DELAY trimmer, 5ā50 s).
The RDL ST-ACR2 trigger circuit is band-pass filtered for a speech-like
spectrum: speech-band noise is the most realistic stand-in for
gallery chatter; the pure tones are for tracing signal through the mixer
(visible on the Mackie meters via channel 1 SOLO). Pair with the free
NIOSH Sound Level Meter app on a second phone to log the SPL each
setting corresponds to.