SOUND PALETTE
®
Series
Automatic Level Control for the SP1200/SP2400
SP-DSP1
DSP
The Mackie Industrial SP-DSP1 is a real-time digital
signal processor that can be installed in the SP1200 or
SP2400. It uses a proprietary algorithm (patent pend-
ing) and adaptive digital filtering to sense noise in
a room with an ambient microphone and adjust the
gain of the program source accordingly. This unique
approach effectively "nulls out" the music sensed at
the ambient microphone, allowing the DSP to measure
the actual ambient noise level in the room. As the
ambient noise level of the room changes, the gain of
the program material automatically adjusts to compen-
sate for those changes.
The SP-DSP1 is designed to be controlled with the
SP-Control™ application running under the Palm™ OS.
The SP-Control application is included on a 3.5" floppy
disk, and it can also be downloaded from the Mackie
Industrial website (www.mackieindustrial.com).
Once installed, the SP-DSP1 attenuates the signal by
up to 40 dB, depending on the setting of the Minimum
Gain control. This determines the lowest level to which
the SP-DSP1 can attenuate the program signal.
The Gain Range control determines the amount of
gain change allowed by the Automatic Level Control.
Add this number to the Minimum Gain setting to deter-
mine the maximum gain allowable.
The Noise Threshold control determines the point
at which the Automatic Level Control begins working.
When the ambient noise level crosses this threshold,
the DSP-1 begins to increase the program signal.
The Noise Range control works in conjunction with
the Gain Range control. The ratio of the two settings
determines how much the program level changes as a
function of the change in ambient noise level. For example,
if the Noise Range is set to 20 dB and the Gain Range
is set to 30 dB, then a 20 dB change in noise level
causes a 30 dB change in program level (a 2:3 ratio).
The Attack Time setting determines the rate at which
the program level increases. The higher the Attack
Time setting, the faster the program level increases
once the noise level crosses the Noise Threshold.
The Release Time setting determines the rate at which
the program level decreases. The higher the Release
Time setting, the faster the program level decreases
once the noise level drops below the Noise Threshold.
The SP-DSP1 can store up to ten preset configura-
tions for various functions or applications.
The Auto Calibration procedure computes the Room
Transfer Function (RTF) and prevents runaway gain.
Features
Adds ambient noise sensing capability to the SP1200
and SP2400 Program Controller/Amplifier
Adaptive digital filtering analyzes the signal at the
ambient microphone and determines the amount of
ambient noise in a room
Automatically adjusts the system gain according to the
ambient noise level
SP-Control™ Palm™ OS application included for
remote control
Adjustable parameters on the Palm™ include minimum
gain, gain range, noise threshold, noise range, attack
time, and release time
Bargraph metering on the Palm™ monitors program
input level, microphone input level, program gain, and
program output level
Auto-calibration function
Upload and download capability from EEPROM to
SP-Control application
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SP-DSP1
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Zoned Music Distribution
Automated Noise-Compensating
Gain Systems
Multizone Paging/Background Music and
Speech Reinforcement Systems
