Specifications

Chesapeake College Todd Performing Arts Center Auditorium
Audio System Upgrade
March 20
th
, 2015
Audio Systems 27 41 00-25
shall be entitled to deduct any money owed to the Owner, PM, Audio Consultant, or
other project team members under this contract from any sum which may become due
or is payable to the Audio Contractor under this Contract for the purposes of satisfying
the charges listed above.
D. Final Acceptance Test
1. Testing will be performed with the Owner (or its designees) present to determine that
the Audio system equipment satisfies the manufacturers’ performance specifications and
that the Audio system installed satisfactorily performs the functions required by this
specification. Conduct formal pre-acceptance tests prior to the Owner’s acceptance
testing to ensure that the performance and functional specifications are satisfied by the
installed system and the system is ready for the Owner’s acceptance. Verify in the
owner’s presence that the installed audio system satisfies the performance and functional
requirements through formal acceptance 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. Audio and control cable, terminations, adapters, etc
b. Audio Test CD
c. DVD
d. Programmable Audio Test Generator, Extron VTG-400D
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.