Installation manual

Community S-Series - Operation and Installation Manual - Page 32
falls below the amplifier’s nominal rating (this is sometimes referred to as a brown-out),
and they may shut down or be damaged if the AC voltage suddenly increases. Conversely,
those that are built around switching-type power supplies may be tolerant of a drop in AC
mains voltage with no loss of output capability. They may also be tolerant of an increase in
AC voltage that’s well above nominal. Many developing countries (and some parts of well-
developed countries) routinely experience a wide range of voltage fluctuations, particularly
during times of peak demand. Certain generators that are used to power outdoor systems
may also exhibit wide voltage fluctuations. Before making a choice of amplifier type, it’s a
good idea to know as much as possible about the characteristics of the available power
where the system is to be used.
Damping Factor: This specification refers to the amplifier’s ability to dampen the motion
of the driver during intervals when the amplifier is not producing output power. When a
driver is energized, it continues to stay in motion for at least a few cycles after the power
applied to it has been discontinued, from stored kinetic energy (momentum). During these
intervals, such as in between kick drum beats, the driver is temporarily generating electric
current that flows back into the amplifier (called back EMF). If the amplifier has a high
damping factor, it will do a good job of electronically ‘braking’ or dampening the motion of
the driver. This will result is an audibly tighter and punchier sound quality compared to an
amplifier that has a poor damping factor. The effect of damping factor is especially
pronounced when the amplifier is used with large, relatively heavy cone drivers, like those
found in large-format subwoofers. This specification is typically expressed as a whole
number or a ratio such as: >200 into 8 ohms or 200:1 into 8 ohms. A higher number is
better.
Signal-to-Noise Ratio: Signal-to-noise ratio refers to how much hum and noise the
amplifier produces. It is typically expressed as either a positive or negative number; e.g.
>100 dB or -100 dB. A higher number, which indicates lower noise, is better.
Slew Rate: Slew rate refers to how rapidly the amplifier can produce output voltage when
an input signal is applied. It is expressed as volts per microsecond (V/µs). Typical
numbers range from 20V/µs to 40V/µs or higher. A high slew rate reflects an amplifier that
can more accurately reproduce the dynamic content of the input signal. However, an
amplifier with a lower slew rate may tend to sound bigger and warmer than one with a
higher slew rate. Listen and compare (see Sound Quality).
Controls and Features: In addition to the standard gain controls and front panel lights,
many of today’s amplifiers offer such features as adjustable low pass filters, remote control
of gain, remote monitoring of status, line voltage monitoring, and even full-blown DSP
signal processing. Some installations may benefit greatly from such capabilities, while
others may not need these features or cannot justify the extra cost. We recommend that
you carefully align your budget with your actual needs. In most situations, you’ll probably
benefit more by installing an adequate number of loudspeakers and amplifiers, than by
spending money on features that might not actually contribute to better performance.
S-SERIES APPLICATIONS
The S-Series loudspeakers can fulfill numerous application requirements. Some of these
are:
• Sound Reinforcement in Houses of Worship
• Theatrical Sound Reinforcement
• Coffee House Systems
• Music Reinforcement in Concert Halls & Performing Arts Centers
• Night Club and DJ Sound Systems
• Auditoria Sound Reproduction
• Presentations in Hotel Meeting Rooms and Ballrooms
• Health Club Exercise Music and Instruction
• Corporate Training Facilities
• Themed Entertainment Venues
• Retail Environments
S-Series loudspeakers are equally suited for use in system designs based on distributed
speakers, exploded clusters, tight clusters, and arrays.