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PurePath™ Smart Amp User Manual (TAS5766M/68M)
41
Once it is verified that audio is working, the Smart Amp
System Gain
calibration can be verified.
System Gain Verification:
1. Calculate the expected thermal limit in volts RMS
using the following equation:
𝑉
𝑡ℎ
_
𝑙𝑖𝑟𝑖𝑡
=
�𝑃
𝑡ℎ
_
𝑙𝑖𝑟𝑖𝑡
×
𝑅
𝑎
.
•
The
𝑃
𝑡ℎ
_
𝑙𝑖𝑟𝑖𝑡
value is obtained from the
Characterization Data panel of the
Tuning
and Audio Processing
page.
•
Click
to obtain
𝑅
𝑎
.
For example,
𝑃
𝑡ℎ
_
𝑙𝑖𝑟𝑖𝑡
= 3
𝑊
and
𝑅
𝑎
= 3.96
Ω
would
correspond to 3.45 V
rms
.
2. Wear hearing protection equipment.
3. Connect the positive and negative terminals of the loudspeaker to a multi-meter (volts AC
setting).
4. Set the volume of the host processor to a low level (e.g. -20dB to -40dB).
5. Play the same excitation frequency that configured during the thermal characterization. A
20 kHz sine tone is typical.
6. Slowly increase the tone amplitude. The measured voltage should settle near
𝑉
𝑡ℎ
_
𝑙𝑖𝑟𝑖𝑡
even as the amplitude is increased to 0dB.
IMPORTANT:
These verification steps only confirm that the algorithm has been correctly
calibrated. It is the responsibility of the customer to perform additional
verification and stress tests to ensure reliability of the loudspeaker system.
