Bose BUILT-INvisible TA-1 Service Manual page 26

4.4 Measure the output level at the bass
channel speaker output at J15 pins 1 and 2.
It should be +38.4 dB + 1.5 dB.
4.5 Apply an in-phase, 100 mV, 20 Hz signal
to the left and right music audio inputs at J6.
4.6 Reference a dB meter to the input level.
4.7 Measure the output level at the bass
channel speaker output at J15 pins 1 and 2.
It should be +19.1 dB + 1.5 dB.
4.8 Apply an in-phase, 100 mV, 200 Hz
signal to the left and right music audio inputs
at J6.
4.9 Reference a dB meter to the input level.
4.10 Measure the output level at the bass
channel speaker output at J15 pins 1 and 2.
It should be +29.9 dB + 1.5 dB.
4.11 Apply an in-phase, 50 mV, 100 Hz
signal to the left and right music audio inputs
at J6.
4.12 Measure the small signal distortion
level at the bass channel speaker output
at J15 pins 1 and 2. It should be < 0.5%
THD+N.
4.13 Apply an in-phase, 230 mV, 100 Hz
signal to the left and right music audio inputs
at J6.
4.14 Measure the large signal distortion
level at the bass channel speaker output
at J15 pins 1 and 2. It should be < 0.2%
THD+N.
4.15 Apply an in-phase, 600 mV, 100 Hz
signal to the left and right music audio inputs
at J6.
TEST PROCEDURES
26
4.16 Measure the compressor signal distor-
tion level at the bass channel speaker output
at J15 pins 1 and 2. It should be < 4.0%
THD+N.
5. DC Offset Test
5.1 Set up the amplifier under test as out-
lined in the test setup.
5.2 With no input signal applied, measure the
DC offset level at the front, center, surround
and bass channel speaker outputs at J12,
J13, J14 and J15. It should be < 10 mVdc.
6. Output Noise Test
6.1 Set up the amplifier under test as out-
lined in the test setup.
6.2 Short out the left and right music audio
inputs at J6.
6.3 Measure the A-weighted output noise
level at the left and right front and center
channel speaker outputs. It should be < 3.0
mVrms.
6.4 Measure the A-weighted output noise
level at the surround channel speaker
outputs. It should be < 330 uVrms.
6.5 Measure the A-weighted output noise
level at the bass channel speaker output.
It should be < 1.0 mVrms.