Owner`s manual

PAGE 6 Community Solutions™ Owner’s Manual
2 INTRODUCTION TO ELECTRONICALLY-CONTROLLED
LOUDSPEAKER SYSTEMS
In simple terms, an electronically-controlled loudspeaker system consists of:
1. The loudspeaker components and enclosure.
2. An associated electronic device that modifies the source signal in some fashion.
3. The power amplifier used to drive the loudspeaker system.
A properly designed electronically-controlled loudspeaker system, in combination with a power
amplifier of appropriate rating, will provide enhanced performance over a non-electronically-
controlled loudspeaker in one or more of the following ways:
• Improved frequency response
• Maximized power handling
• Higher acoustic output
• Lowered distortion
• Protection of the loudspeaker system components
All loudspeaker systems have frequency response limitations. Flat response from a system is typically
attained by lowering the output in certain portions of the system’s passband to match the lower output
of the system at other frequencies within its passband. As a consequence the overall sensitivity of the
system is lowered. Rather than modifying the system, the input signal may be modified by an
electronic controller to compensate for those areas within the system’s passband where it would
normally have lower output. In this way flat frequency response can be achieved while maintaining the
sensitivity of the system.
All loudspeaker systems have power handling limitations beyond which they can be damaged. An
electronic model may be developed with characteristics that help prevent exceeding the mechanical
and/or thermal limits of the system’s components. For example, suppose it can be determined with
accuracy that an input signal of 20 volts to the voice coil of a driver will cause the voice coil former to
strike the rear of the magnet assembly. If the electronic model for this speaker is designed so that the
input signal to the driver’s voice coil may never exceed 19.5 volts, then it should never be capable of
bottoming out.
Some other important operational characteristics may also be addressed by a controller. One is
compensating for the natural characteristics of human hearing, which does not “hear” low frequencies
and high frequencies as well at lower sound pressure levels. The controller can increase the output of
these frequencies at low volume (in essence, a sophisticated loudness control). The controller can
then reduce the output at these frequencies as the signal level is increased. Another is providing an
electronic crossover function; while yet another might be to correct for phase anomalies in the
loudspeaker system.
A properly designed electronic system controller will provide the necessary equalization, compression,
and limiting required for the associated loudspeaker system. It will do this inaudibly when the
loudspeaker system is operated within its rated power constraints. Even when this boundary is
exceeded, it will apply control in a manner that is audibly acceptable.