Electro-Voice Q1212 1800 watt per channel Class-H power amplifier

In the EV Q1212, with Q Series' efficient Class-H design, the permanent voltage rail is designed to cover the average music signal, rather than permanently supplying the voltage for maximum output power. If dynamic peaks require a higher output voltage, the voltage rail is switched to the maximum. This process saves up to 50% of the power consumption found in conventional amplifier design, and results in a dramatic reduction in heat output. Q Series combines the sonic excellence and ruggedness of its Precision Series predecessors with Class-H innovation, all in a compact and affordable package.

While many people understand there are tremendous differences between professional loudspeakers, many also tend to think that amplifiers are only differentiated by the amount of output power they provide. Electro-Voice amplifiers serve to prove that there are also audible differences.

Dynamic Headroom

Amplifier power and distortion figures are typically specified with sine wave signals. However, music signals are far more dynamics than sine waves, comprising a pulsed wideband spectrum.

EV believes that, above all figures, the tonal performance of live music counts most; therefore, all of their amplifiers are designed for dynamic headroom. This means that each and every EV amp has at least 30% more output capability for short-term signals, when compared to a long-term sine wave value. This additional headroom results in an amp that will, for example, allow for short term signal peaks of at least 780W when spec'd 600W.

While dynamic headroom is audible when playing music through a sound system, another specification to observe is the increase in output power from an 8 ohm load to 4 ohms, and then down to 2 ohms. Of course, all Electro-Voice amplifiers are designed to be absolutely stable into loads of 2 ohms.

Transient Response

When processing dynamic signals, other important criteria are signal speed and dynamic distortion. For example, kick drum signals carry pulses of many frequencies as an overlay spectrum. Therefore, and in contrast to many other manufacturers, EV specifies a lot more information on their amplifiers' dynamic behavior than just "slew rate" figures. Important tests referring to the amp's ability regarding multitone signal pulses are expressed by IMD-SMPTE measurements at high power levels. And, while IMD tests show the Intermodulation Distortion behaviour (how much "sound" is added by the ampifier), DIM30 is the real spec for speed in an amplifier. All these tests are carried out in EV labs during an amplifier's design phase, to ensure maximum sonic performance. While these technical explanations appear very complex, they are clearly audible. Take a Q Series amplifier and crank it up - you'll hear the difference immediately.

Protection Package & Dynamic Limiter

There are many good-sounding amplifiers available; however, for an amp to be considered the world's best requires unparalleled reliability in real-world applications.

Q Series amplifiers benefit from decades of professional amplifier design, and all the expertise that has made EV amps the concert/touring standard is built into Q Series. Our complete protection package includes sophisticated circuits against overheating, short circuit, DC output voltage, HF oscillation, back EMF (Electromotive Force), and destructive peak current.

Furthermore, Q Series amps also protect your valuable loudspeakers with built-in dynamic limiters, preventing dangerous output clipping. The limiters immediately reduce amp gain when dynamic headroom is pushed to the limits at maximum output, keeping distortion below 1% in a situation that can otherwise cause a signal to clip, which is often fatal for woofers and drivers.