Instruction manual

Networked PIP Series
page 36
Reference Manual
These anomalies are easily averaged out by the PIP supervision algorithm in most systems.
However, there may be some extreme situations for very narrow bandwidth (i.e. single-note)
signals and/or very widely varying loads that the algorithm simply cannot overcome. In
these cases, widening the high and low limits will help decrease the “sensitivity” of supervi-
sion and decrease the chance of “nuisance” error reports.
5.3 PIP-USP3 and PIP-USP3/CN Features
5.3.1 Input Signal Router
Each channel of the PIP’s signal processing has an Input Signal Router that allows the
choice of audio signal that will be used by the channel. The user may choose the following
configuration:
• Analog Audio: This is the audio input from the audio connector on the front panel of
the PIP. Choices for the Analog Audio input are Channel 1, Channel 2, or a sum of Channels
1 and 2.
5.3.2 Filters
Each audio channel has five separate places where filters can be placed in the system. There
are 64 filters total within the USP3 or USP3/CN and they can be placed anywhere within the
system. In addition to filtering, each possesses up to +/-24dB of gain. The filters will vary
based on the firmware and software being run. The following filters are available:
• Lowpass: Bessel 2-4, Butterworth1-4, and Linkwitz-Riley 4 (Firmware 2.0 provides up to
8 Linkwitz-Riley filters)
• Highpass: Bessel 2-4, Butterworth1-4, and Linkwitz-Riley 4 (Firmware 2.0 provides up to
8 Linkwitz-Riley filters)
• Lowshelf: Low-frequency shelving EQ
• Highshelf: High-frequency shelving EQ
• Lowpass EQ: Variable Q from 0.1 to 35
• Highpass EQ: Variable Q from 0.1 to 35
• Parametric EQ: Variable Q from 0.1 to 35
• All Pass: 1st and 2nd order
All Pass filters provide no gain change to the output, but provide a phase change at the
selected frequency. This corrects the phase relationship of the output without a gain reduc-
tion, such as is found in other filters.
5.3.3 Delay
Due to the nature of DSP processing, there is some inherent delay or latency within the PIP.
These delays are:
• Balanced Audio Input ADC: 250 µs for the USP3, 312 µs for the USP3/CN
• USP3 DSP Processing: 665 µs
• USP3/CN DSP Processing: 665 µs
• Output DAC: 135 µs
• USP3 input to output: 250 µs + 665 µs + 135 µs = 1.050 ms
• USP3/CN CobraNet input to output: 665 µs + 135 µs = 800 µs
• USP3/CN Analog input to output: 312 µs + 665 µs + 135 µs = 1.112 ms
136763-7_4-08_networked_pip-series_reference_manual.fm Page 36 Monday, March 17, 2008 11:17 AM