User guide

CENTER FOR ALLIED HEALTH AND ATHLETICS FF&E April 24, 2014
SECTION 27 41 00 AUDIOVISUAL SYSTEMS
Marshall Craft Associates, Inc. 27 41 00-33
Project 12032
testing. Be responsible for staging each room to be tested, and shall have sufficient
personnel on site to run multiple systems at once (not less than three (3) personnel).
E. Test Equipment
1. Assemble the following test equipment (or equivalent) on site.
a. Video signal generator, Leader 410C
b. Combined waveform monitor/vectorscope, Leader 5872A
c. Prerecorded VHS tape (NTSC)
d. RGB HV cable, Extron BNC-5-6’HR
e. Audio and Video cable, terminations, adapters, etc
f. Audio Test CD
g. DVD
h. Programmable Video & Audio Test Generator, Extron VTG-400D
i. HDMI/DVI Test Signal Generator
F. Audio System Testing
1. Absolute Impedances
a. Set any speaker level controls at zero attenuation. Measure absolute impedance
value of each speaker line at 250, 500, 1000, 2000, 4000 Hz without the amplifier
connected but with all speakers connected. Impedance must not be below the
rated load impedance of respective amplifier and may be any value equal to or
above that. Check resistance of lines to all speakers and microphone
receptacles with receptacles open and short-circuited.
2. Hum and Noise Level
a. Test overall hum and noise, it should be at least 60 dB below rated power output
of each amplifier with amplifier controls set for optimum signal to noise and full
output and with inputs terminated with proper shielded resistor. (150 and 600
ohms).
3. Parasitic Oscillation and RF Pickup
a. Set up system for each specified mode of operation.
b. Use 5 MHZ band with oscilloscope and speaker monitoring.
c. Check to insure that the system is free of spurious oscillation and RF pickup in
the absence of any input signal and also with the system driven momentarily to
full output at 160 Hz.
4. Buzzes, Rattles, Distortions
a. Apply high quality music signal to the system. Adjust the sound system for
frequent peaks at its specified maximum sound pressure level.
b. Apply sine-wave sweep from 50 to 5,000 Hz to 6 dB below full amplifier power.
c. In both cases, listen carefully for buzzes, rattles and objectionable distortion.
d. Correct all causes of such defects. If cause is not from system, promptly notify
the architect indicating cause and suggested corrective procedures.
5. Equalize all audio systems for maximum gain before feedback in all room
configurations.
6. Record all systems settings and include into Systems Operation manuals
G. Video System Testing
1. Signal Paths
a. Utilizing a NTSC color bar generator and waveform analyzer with the video
signal set at 100% saturation and 75% amplitude check that the video
performance specifications are met at the display devices from all source inputs
to all system outputs. Connect the combined waveform monitor/vectorscope to a
final output point, e.g. an input to a picture monitor or video projector. Ensure
that the test signal is routed to the selected output.