Specifications

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CHAPTER 3: PROCESSING BLOCKS
The Converge Pro 880 and 8i features the power of eight processing blocks, which are dedicated signal processing
resources that can be applied to any mic or line input routed to it. The Converge 840T features four processing blocks.
Within each processing block, compression, delay, gain adjustments, and up to 15 different filters may be applied to any
mic/line input, or combination of inputs routed to the block. Each input also has four assignable filters for shaping the
input audio signal.
FILTERS
Feedback
Perhaps the most common (and the most annoying) problem for professional sound engineers is feedback. Feedback
is often a high, piercing tone caused when mics pick up resonant frequency and amplify it through the sound system,
where it is picked up again by the microphones and amplified.
In addition to being painful to hear, feedback can cause amplifiers to clip, which can destroy drivers and loudspeaker
components. While most feedback can be controlled through proper microphone placement, resonant frequencies can
be attenuated using filters such as parametric equalizers.
Low frequency feedback isn’t necessarily audible, but it decreases the system’s power and responsiveness. By
attenuating the low-end frequencies not needed for vocals, with low cut /high pass filters, the Converge Pro operates
more efficiently.
Converge Pro Filters
The Converge Pro provides customizable filters for feedback control. These filters can boost or attenuate certain audio
frequencies, compensate for poor acoustics, and fine-tune your sound system. Some filters, such as pass filters, allow
you to select a range of audio frequencies above or below a given point and attenuate them, while others allow you to
attenuate specific frequencies. Filters are also excellent for use in cancelling frequency ranges that cannot be transmitted
through telephone lines, thereby freeing up system resources.
Filters
The Converge Pro 880, 880T, 840T, 8i, and Converge SR 1212 feature the following filters:
All Pass• . A filter that provides only phase shift or phase delay without significantly changing the magnitude of the
signal. Useful in custom crossovers designed to compensate for loudspeaker driver deficiencies.
CD Horn Equalizer• . A constant directivity horn driver has an inherent 6dB/octave high frequency roll-off. This
filter produces a 6dB/octave boost to compensate. The CD horn equalizer is implemented using a high shelving
filter. The level control is fixed at +12dBen.
High Pass• . This filter allows frequencies above a designated frequency to pass while attenuating those below it.
This filter attenuates low, rumbling noises like those captured by a microphone when placed on a stage, table, or
in a microphone stand.
High Shelving• . This filter boosts or attenuates frequencies above a designated frequency while leaving those
below it unaffected. The transition between the spectrum above and below the designated frequency occurs at a
fixed 6dB/octave rate. When boosted, it enhances the higher, more intelligible aspects of the vocal range. When
cut, it eliminates extraneous sibilance (like a constant “ssssssss” noise).
Low Pass• . Allows frequencies below a designated frequency to pass while attenuating those above it.
Low Shelving• . Boosts or attenuates frequencies below a designated frequency, leaving those above it
unaffected. The transition between the spectrum above and below the designated frequency occurs at a fixed
6dB/octave rate. Excellent for enhancing the low-end range of a signal.