3M DL Music Mixer User Manual


 
79 Additional options
Reverberation (RT60) methods
Models SE and DL
Interrupted noise
The Interrupted noise method, applied with pink noise, is used with a portable
sound system, such as a dodecahedral speaker, or with an existing sound system
(only recommended if the sound system has a quality, omni-directional, sound
system.) With the interrupted noise method, the sound source emits a high-level
source and falls-off, returning to its original ambient background level. The Reverb
Time is measured between T
1
and T
2
indicators with an ending RT60 time value.
NOTE: T
1
is calculated from two reference points on the regression line to
ensure an accurate sound level capture
Figure 6-2: Interrupted noise example
Impulse noise
The Impulse noise method requires a broad-spectrum impulsive noise source, such
as a starter pistol, in a room to be tested. Typically, the RT60 decay start will begin
at a high-level source and decays, reporting a Reverberberation Time.
T
1
T
2
Background
noise level