Bose Panaray 502A Service Manual page 43

2. Gain Test
2.1 Set the input switches to -10 dB.
2.2 Apply a 100 mVrms, 600 Hz signal to the
input terminals.
2.3 Measure the gain at the high frequency
outputs. The gain (referenced to the input)
should be 16.5 ± 1.0 dB.
2.4 Change the input level switches to
+4 dB.
2.5 Measure the gain at the high frequency
outputs. The gain (referenced to the input)
should be 2.5 ± 1.0 dB.
3. Sum Output Mode Gain Test
3.1 Set the input switches to +4 dB.
3.2 Set the output mode switch to Normal
and the low frequency level potentiometer to
+3 dB.
3.3 Apply a 100 mVrms, 80 Hz signal to the
502C's input terminals.
3.4 Measure the gain at the Channel 1, low
frequency output. The gain (referenced to
the input) should be 8.7 ± 1.0 dB.
4. Frequency Response of High Frequency
(HF) Output (Full Range Mode)
4.1 Set the mode switch to 1 (Full Range).
4.2 Apply a 100 mVrms, 600 Hz signal to the
502C's input terminals and reference your
dB meter to this frequency.
4.3 Measure the frequency response across
the HF outputs according to the following
table.
TEST PROCEDURES
43
Frequency (Hz) Response (dB)
40 -24.5 ± 2.0
140 +4.3 ± 1.5
600 REF
2200 +3.5 ± 1.5
5000 +12.5 ± 1.5
15000 +19.0 ± 1.5
5. Frequency Response of HF Output
(Bi-Amp Mode)
5.1 Set the mode switch to 2 (Bi-Amp).
5.2 Apply a 100 mVrms, 600 Hz signal to the
502C input terminals and reference your dB
meter to this frequency.
5.3 Measure the frequency response across
the HF outputs according to the table below.
Frequency (Hz) Response (dB)
40 -28.5 ± 2.0
140 +3.7 ± 1.5
600 REF
2200 +3.5 ± 1.5
5000 +12.5 ± 1.5
15000 +19.0 ± 1.5
6. Frequency Response of Low Fre-
quency (LF) Output (Bi-Amp Mode)
6.1 Apply a 100 mVrms, 80 Hz signal to the
502C input terminals and reference your dB
meter to this frequency.
6.2 Measure the frequency response across
the LF outputs according to the table below.
Frequency (Hz) Response (dB)
40 -6.2 ± 2.0
80 REF
100 +1.3 ± 1.0
300 -17.5 ± 2.0
7. Midrange Distortion (Full Range Mode)
7.1 Set the mode switch to 1 (Full Range).
7.2 Apply a 3.75 Vrms, 600 Hz signal to the
502C input terminals.