Larson Davis System 824, Training Manual

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3/22/01 RT60 Measurements 3-3
Taking an RT60 Measurement
This next section will take you through a step by step pro-
cess for acquiring an RT60 measurement.
Exciting the Room
To find out the absorption qualities of a particular room
using an RT60 measurement, you will have to energize the
room with some sound source. There are two basic methods
for energizing a room with sound:
• A continuous noise source such as a pink noise generator
and a speaker (preferably an omni-directional speaker).
• An impulsive noise source such as a starter pistol, canon,
balloon, etc.
Setting up the 824 for an RT60
measurement
For an RT60 measurement use the RTA instrument of the
824.
Step 1
To select the RTA instrument, press the SETUP
key. Use the up and down arrow keys and high-
light either “RT60-A” or “RT60-B” and press the
Check
key.
RT60-A and RT60-B Setups
There two setups named “RT60-A” and “RT60-B”. The
“RT60-A” setup is configured to gather data to measure an
RT60 by exciting a room with steady sate noise (typically
using a pink noise generator and speaker system). The
“RT60-B” setup is configured to measure an RT60 by excit-
ing a room with impulsive noise such as a gunshot or pop-
ping a balloon or paper bag.
Step 2
Press the SETUP
key again. With “Edit Set-
tings” highlighted, press the Check
key. The
following page shows the settings for RT60-A.
NOTE: The menus are the same for all
RTA instruments.