SP395 SoundPro Audio Integrator Form7492 Operation Manual
64
STI-PA Description
STI-PA is a subset of STI that uses 9 data points, spanning the 125 Hz to 8000Hz octave bands,
but using only one modulation speed for each data point. STI-PA has been shown statistically to
correlate well with STI, even though it has 1/10
th
the data points.
The SP395 STI-PA implementation is unique, using an STI-PA excitation signal and proprietary
DSP algorithms for determining loss of modulation. The STI-PA test signal is played from the
supplied CD, and the signal is sampled for 15 seconds. The STI-PA value is calculated and
shown on the SP395 test screen.
STIPA Measurement screen and control fields descriptions.
STIPA Test Screen and Control Fields:
1. Test Function – Identifies STIPA as the selected function and measurement screen.
2. STIPA Test Value – This is the STIPA measurement or index value after a valid test is
performed. The readout range is .00 to 1.
3. Off/Run – This field begins the test by selecting “RUN” and turns the test function off by
selecting “OFF.”
4. Octave Test Bands – Column listings of the octave bands within the CD test signal used
by the STIPA test to measure modulation reduction factor (m) and compute S/N values.
5. S/N Ratio Measurements – values measured by the STI PA test for each of the
modulation signals.
6. Modulation Reduction Factor (m) – values measured by the STIPA test for each of the
bands.
7. Mean Value – Mean value of the apparent S/N ratio values measured/computed within
the STIPA test.
To Next Page
Loading...
