The M4000 Power Amplifier is the culmination of Mackie's research into the world of high efficiency sound reinforcement, boasting a three rail Class H power design. The extra power rails are only engaged when the amplifier is driven at high volumes, maintaining a lower power draw, and lower temperatures, when the second and third rail are not required. The M4000 utilizes two variable speed fans for cooling, bringing cool air into the unit from intake vents located in the rear. Because these fans spin at extremely low speeds (or not at all) when the amplifier is running at low volumes, the M4000 can be used in a studio without worry that the fans will disturb a recording or mixing session. This high level of efficiency allows the M4000 to have a much longer expected lifespan than other types of power amplifiers, enabling Mackie to back each unit with a five year limited warranty against defects or equipment failure.

At the rear of the unit are two switches for each channel, to independently enable or disable 150 Hz crossover or volume limiting on a per channel basis. The crossover function is useful when a different type of speaker load needs to be connected to each channel, such as a subwoofer on one and a main speaker on the other. Also, the crossover function can be used to bi-amplify a single speaker. The limiting function, meanwhile, halts the damage that can be caused by transient attacks before they occur. The momentary volume increase of snare drum hits or bass slaps can cause speaker damage if they are allowed to pass through an amplifier as clipped waveforms. When enabled, the M4000's limitation function automatically reduces the volume of these transient attacks, preventing clipped waveforms from reaching the speakers and potentially causing permanent damage.

The Mackie brand name is very familiar to musicians and studio operators throughout the world. Mackie has gained fame for providing top quality studio amplification, speakers, mixers, and more, and have entered the world of live sound with their M-Series of power amplifiers. Mackie M4000 Power Amplifiers are the flagship model from the M-Series, providing a maximum of 4000 watts of muscle in a package that is as comfortable in the studio as it is on stage.

Mackie M4000 Power Amplifiers - Summary:
* Rated for a maximum power output of 4000 watts in mono bridged operation, or 2000 watts per channel when driving 2 ohm stereo speakers
* 150 Hz crossover function enables different speaker loads to be driven on the same unit, such as a subwoofer on one channel and main speaker on the other
* Limiter transparently reduces the volume of transient attacks, preventing clipped waveforms from causing damage to the speakers
* Highly efficient dual fan cooling system operates in near silence when the amplifier is operated at low power levels, appropriate for studio monitor environments