Owner`s manual

4
RTA SERIES II
INTRODUCTION
A real-time audio analyzer (RTA) is an audio measurement tool that graphically
shows two kinds of information:
1. The frequency response of an audio system or device, and
2. The frequency response of the listening environment.
This kind of information is very useful for equalizing a P.A. system, finding
feedback hot spots, or "nodes", in reinforcement situations, and flattening the
frequency response of other audio equipment.
RTAs that show both the entire audible frequency spectrum (20 Hz to 20 kHz)
and its entire dynamic range (loudness from 0 dB to 120 dB) are called spec-
trum analyzers. RTAs that show portions of the dynamic range are called
“window” RTAs.
ABOUT THE DOD RTA
The DOD Electronics RTA Series II is a window-type RTA. It covers the audi-
ble frequency spectrum (20 Hz to 20 kHz), and has a five LED level meter for
each of the 31 audio frequency bands that it covers.
The RTA Series II includes a calibrated audio measurement microphone. This
microphone is equipped with a 40 foot cable which enables you to position the
microphone in several locations in the reinforcement area as you make your
evaluations of the audio system. ONLY THIS MICROPHONE SHOULD BE
PLUGGED INTO THE JACK ON THE FRONT OF THE PANEL OF THE RTA. Other
microphones may be damaged or give inaccurate readings.
The sensitivity of the RTA can be modified using the input level control, and
the window of the RTA may be widened or narrowed using the Resolution
switch. This switch allows you to choose the LED display range in dB per
LED. You can choose either a 1 dB per LED step (for a 4 dB wide window) or
a 3 dB per LED step (for a 12 dB wide window).
MAXMIN
PINK
NOISE
MAXMIN
INPUT
GAIN
20K16K12.5K10K8K6.3K5K4K3.15K2.5K2K1.6K1.25K1K8006305004003152502001601251008063504031.52520
2/6
1/3
0/0
-1/-3
-2/-6
ON1dB
OFF3dB
WINDOW
RES.
PINK
NOISE
CALIBRATED
MICROPHONE
R
TA series II
r
eal time audio analyzer
Signal Processors 18-0121-B 6/8/99 10:24 AM Page 4