Loudspeaker Management System – A loudspeaker manager system integrates the functions of gain, delay, equalization, crossover, delay, and limiting at the per audio power amplification level to provide control as close to the speaker level as possible. A system typically include 2 to 4 inputs with gain, equalization, and delay connected to internal distribution busses allow overall for adjustment on each input. Included are 4 to 8 outputs with a distribution bus selector, gain, crossover, equalization, limiting, phase and delay features for each output that allows for the precise set-up of multiple loudspeaker systems or arrays for a sound system.
Signals can be split in various ways to assure precise sound by using the optimal frequency range of each loudspeaker. There are precise dynamic EQs for level-dependent equalization and parametric EQ selectable for all inputs and outputs, and “Zero“-attack limiters on all output channels guarantee optimal signal and loudspeaker protection. The delays for all inputs and outputs are adjustable. This allows you to manually or automatically correct for room temperature, phase and arrival time differences. A loudspeaker management device is equivalent to six to eight crossover in one package giving you several options of operation.
Looking at each of the functions provided in the system. Detail include:
- Input Gain to accomplish unity gain through the system to maximize outputs.
- Input Delay provide for a group delay for zone feeds would be one example where zone delay is required when a set of speaker provide the same output but are located a distance away from each other.
- Input PEQ (Parametric Equalization) uses low pass, band pass and high pass filters to provide the equalization required. The low and high pass are provided with a 6 or 12 dB per octave slope and the band pass with a Q factor for the width adjustment of each these filters.
- Input DEQ (Dynamic Equalization) defined a set of parameters to be used when the define threshold has been exceeded. With this threshold parameter Ratio, Attach and Release parameters are provided as with a compressors.
- Output Gain is used to accomplish unity gain to maximize output to the amplifier. In turn maximizing gain through to system will increase head room at the amplifier output.
- Crossover parameters include the selection of frequency range to pass to the output that will allow to define the frequency for the crossover points and the slope of the filter. Typically provided are the Linkwitz-Riley, Butterworth and Bessel filters with slope from 12 to 48 dB/octave.
- Output PEQ (Parametric Equalization) uses low pass, band pass and high pass filters to provide the equalization required. The low and high pass are provided with a 6 or 12 dB per octave slope and the band pass with a Q factor for the width adjustment of each these filters.
- Output DEQ (Dynamic Equalization) defined a set of parameters to be used when the define threshold has been exceeded. With this threshold parameter Ratio, Attach and Release parameters are provided as with a compressors.
- Output Limiter threshold settings will limit the output peaks suppressing harmful peaks that reduces or eliminates clipping potential that can be harmful to your speakers and providing additional headroom for the amplifier.
- Output Polarity or Phase is used to swap the output phase to get speakers in phase with other speakers.
- Output Delay allows for the slight phase adjustment for speaker element alignment.
http://www.behringer.com/EN/downloads/pdf/DCX2496_P0036_M_EN.pdf Loudspeaker Management System
Alternative with Amplifier Embedded DSP
This Loudspeaker Management System is required if you are using amplifiers with no embedded DSP (Digital Signal Processing).
The amplifiers that do have this embedded DSP, a Loudspeaker Management System is not required because this same DSP functions are provided with each channel of the amplifier. This DSP function provides the amplifier mode functions (Stereo, Dual Mono, BiAmp and Bridge) as well as the Loudspeaker Management System functions. These function includes a Delay, Crossover, Parametric EQ, Dynamic EQ and Limiter.
With a multiple amplifier system, you can use a Behringer ULTALINK PRO MX882 as a splitter for amplifier distribution allowing one or two specific inputs routed to several amplifiers.
A crossover provides the active filtration of frequencies of the processed audio signal for amplification. Each range of frequencies require different types of speakers and speaker cabinet design to meet the requirements of sound reproduction. Also it requires more power as the frequency lowers to obtain the same level of output. This is the reason for the separation of these frequencies and allows the focus of power requirement where needed. This technique is known as bi-amp or tri-amp function.
Typical frequencies are separated and defined as follows:
Frequency Range: Sub Mid-Bass Mid High
Frequency (Hz): 35 to 125 125 to 800 800 to 5k 3k to 18k Hz
% Total Power: 50% 25% 15% 10%