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スピーカーシステム Community MVP12MのPDF オーナーズマニュアルをオンラインで閲覧またはダウンロードできます。Community MVP12M 20 ページ。 Mvp series ii

Community Professional Loudspeakers

MVP™ Series II Owner's Manual

About Dyna-Tech™ Driver Protection

Community's Dyna-Tech™ circuitry provides repeatable protection for the loudspeaker system as a

limiter that converts excessive current into heat. This reduces the current, and thus the power, to the

driver. When triggered by excessive inputs, a red LED on the rear panel provides indication. When the

current limiting system is activated, there will be a noticeable drop in the system's level. The red LED

serves as a warning to the operator about the excessive power and the need to reduce the input level to

the system.

How Community's Dyna-Tech™ Circuitry Works

Community's Dyna-Tech™ circuitry not only provides protection for all drivers in a loudspeaker but

offers multiple levels of protection. Dyna-Tech™ does not use light bulbs. Instead we use High Positive

Current Coefficient Resistors (HPCCR's) specifically designed for Community with the precise

parameters needed for this application: predictable impedance and a very smooth relationship between

current and impedance.

For short term excessive power inputs occurring at high frequencies, the excess power to the HF drivers

is absorbed by the HPCCR's wired directly in series with the high frequency driver. For longer term,

lower frequency, or more excessive inputs, a voltage sensitive relay that normally bypasses the signal

around the current limiters, is activated. It is tripped when the input voltage reaches a pre-determined

level. When open, it puts high-wattage resistors in series with the entire system to dissipate excess

current. The relay resets itself when a pre-determined reduced input voltage level is reached, taking the

resistors out of the signal path. However, if the excessive voltage condition continues, the relay will re-

open and reduce power to the drivers again.

Figure 1 – Example of MVP™ Series II Protection Circuit

There are numerous advantages to this type of voltage sensitive protection circuit. The trip point is pre-

set on the crossover to trip into protection at exactly the same time on all speakers powered from the

same amplifier. The protection circuitry does not rely on, and is not affected by, heat build up. Circuit

breakers (both mechanical and solid-state) rely on heat build-up before they will trip, which severely

limits their ability to protect a cold speaker. The trip points of these breakers are affected by heat, small

variations in speaker impedance and other component tolerances, all of which will cause them to be

erratic. Because the circuit does not rely on heat, it can react almost instantaneously to excessive increases

in level. The circuit will also remove protection as soon as a reduced level is reached, it does not need to

wait for a circuit breaker to cool down. This means your speaker can operate at its full dynamic range and

still react quickly to excessive musical transient peaks without worry of damaging the speaker. It also

means your speaker is protected from the instant the power amplifier is plugged into it and/or turned on.