ESX QS-FOUR - 4-Channel Class D Nano Digital Amplifier

ESX QS-FOUR

Following the tremendous success of the sensationally small QS-TWO 2-channel power amplifier (only 90 x 35 x 70 mm), ESX set itself the goal of developing an equally small but powerful 4-channel version. With the brand new QS-FOUR, this ambition has now become a reality: the ultra-compact 4-channel power amplifier is available now – and is only 10 mm wider than the 2-channel model. With an impressive 4 x 60 watts RMS in a unit measuring just 90 x 35 x 80 mm, it sets new standards in the field of nano amplifiers.

Many people ask: Why so small? The answer is simple: Mini power amplifiers can be installed directly in the dashboard as plug-and-play ISO variants. Simply connect the cables – and the front and rear speakers are supplied with power, including a power connection. The special feature: in vehicles with an ISO connection, everything is already prepared so that no additional power cable needs to be laid. The QS-FOUR is perfectly suited for this. Thanks to its impressive efficiency of up to 90%, it only requires 5 to 10 amps of continuous current when listening to music – a power output that the factory power cables can easily handle.

If you want more bass, that's no problem either: the QS-FOUR has special low-level outputs that can be used to control active subwoofers such as the Q168A, Q201A, or HZ800A. These outputs can also power larger monoblocks such as the QL500.1 or QL750.1, which are suitable if you want to install separate subwoofers.

Once connected, the QS-FOUR will amaze you. In most cases, the factory speakers are much better than you think. Often, it is the built-in radios that simply do not deliver enough power. If you want to listen to loud music, the speakers will "scratch." Anyone who thinks this is due to the speakers is mistaken. The supposed "scratching" usually comes from the amplifier built into the radio, which is at its limit.

When operating at full load, the amplifier distorts. This is referred to as "clipping." An additional amplifier always provides a remedy here. However, these are often very large and must also be connected to the battery with power cables as thick as your thumb. ESX has developed the QS-FOUR specifically for this purpose, which delivers up to 4 x 60 watts RMS, 4-6 times more power than conventional radio amplifiers. And it does so with very low power consumption, the lowest distortion factor, and state-of-the-art Class D technology.

The nano amplifier is also available as an ISO version.

Features

• Efficient Class D amplifier with ultra-compact dimensions
• Heavy cast heat sink with optimal cooling properties
• Automatic switch-on function
• High-level inputs with Error Protection System (EPS®)
• Start/stop ready
• RCA inputs (via cable plug)
• Stereo RCA output for active subwoofers, for example
• HPF/LPF switchable for front and rear
• Perfect for HD audio

Technical

• 4-channel Class D Nano digital amplifier
• 4 x 35/45/60 watts RMS @ 4/3/2 Ω
• 2 x 120 watts RMS @ 4 Ω bridged
• 2 x HPF/LPF @ 80 Hz
• Total harmonic distortion THD+N @ 5W/RMS < 0.007%
• Frequency range 10 Hz to 60 kHz
• Dimensions 90 x 35 x 80 mm
• Efficiency up to 90%