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The approximately palm-sized 2-channel mini power amplifier QM-TWO caused amazement right after the presentation among ESX fans and connoisseurs of the car hifi scene. The small powerhouse with a whopping 240 watts RMS output was immediately traded as an insider tip. After last year's improved V2 version with incredible 300 W RMS performance topped that again, ESX is now adding two more models in the QM class: The powerful QM-FOUR power amplifier is now available for 4-channel applications, who want to drive a separate subwoofer, can now use the new monoblock QM-ONE. Both power bars deliver a whopping 360 watts RMS and are visually perfectly matched. Modern and efficient Class D technology is used in all models, combined with EPS, top features and perfect sound characteristics. The QM-FOUR amp is very compact at just 21.6 x 8.4 cm and is already considered one of the smallest 4-channel power packs on the market. With a clean 4 x 90 watts RMS at 2 ohms, the potent mini-amplifier can completely fuel a full-fledged front and rear system. But a subwoofer can also be driven in bridge with up to 180 watts RMS at 4 ohms, especially thanks to the extensive filter section. The QM-FOUR-PP Plug&Play Edition is ideal for reinforcing a factory system. Only one condition has to be met for this: The radio must be equipped with a modern Quadlock plug ex works. In this, the loudspeaker plug insert can be easily removed and connected to the enclosed 5 meter cable harness of the QM-FOUR-PP. Finally, the Quantum QM amplifier only needs to be supplied with power and that's it!

  • Efficient Class D Amplifier with ultra-compact dimensions
  • Heavy die-cast heat sink with perfect cooling characteristics
  • Auto Turn-On Function
  • High Level Inputs with EPS, Start/Stop Ready
  • Adjustable Highpass- & Lowpassfilter
  • Adapter Harness for Power Quadlock Head Units (5 m)

QM-FOUR-PP € 279,00*

4-Channel Class D Plug&Play Mini Digital Amplifier

720 Watts Max. Output Power

4 x 52/90 Watts RMS @ 4/2 Ohms

2 x 180 Watts RMS @ 4 Ohms bridged

HPF/LPF 40 - 4000 Hz (CH1/2)

HPF/LPF 40 - 4000 Hz (CH3/4)

Bass Boost 0 / 6 / 12 dB (CH1/2)

Bass Boost 0 / 6 / 12 dB (CH3/4)

Input Selector 2CH/4CH

Clipping LED

RCA Inputs & Outputs (Adapter Harness)

Adapter Harness for Power Quadlock Head Units (5 m)

High Level Inputs with EPS

Auto Turn-On Function

Dimensions: 216 x 39 x 84 mm


Owner's Manual

Test Review

* Manufacturer's suggested retail price, changes and mistakes reserved