ESX QS-FOUR-ISO

The ESX QS-FOUR-ISO is an exceptionally compact 4-channel Class D amplifier designed specifically for hassle-free plug-and-play retrofits in vehicles equipped with an ISO connection system. Despite its extremely small dimensions of just 90 x 35 x 80 mm, the amplifier delivers an output power of up to 4 x 60 watts RMS.

Using the included 60-cm ISO Plug+Play wiring harness, the amplifier can be connected directly between the factory radio and the vehicle's wiring in compatible vehicles. This allows front and rear speakers to be powered with significantly more power without having to perform extensive rewiring.

The modern Class D circuit achieves an efficiency of up to 90%, thereby enabling high output power with comparatively low power consumption and heat generation. Especially in factory-installed audio systems, the additional amplifier power can provide higher volume levels, better speaker control, and reduced distortion.

In addition to high-level inputs with ESX EPS®, the QS-FOUR-ISO also features low-level connections. An additional stereo RCA output allows you to connect another amplifier or an active subwoofer.

Technical Specifications

• Amplifier Type: 4-Channel Digital Amplifier

• Amplifier Technology: Class D

• Number of channels: 4

• Operation on 12-V vehicle electrical systems

• RMS output power at 14.4 V:

  • 4 x 35 watts RMS at 4 ohms

  • 4 x 45 watts RMS at 3 ohms

  • 4 x 60 watts RMS at 2 ohms

• Bridged output power:

  • 2 x 120 watts RMS into 4 ohms

• Supported speaker impedance: 2–8 ohms

• Frequency range: 10 Hz – 60,000 Hz

• Total harmonic distortion at 5 watts: 0.01%

• Damping factor: 68

• Signal-to-noise ratio: 101 dB

• Efficiency: up to 90%

• Operating voltage: 7.3 – 16.4 V

• External fuse: 25 A

• Start/Stop-capable
  
  

Inputs

• 4-Channel High-Level Input:

  • Front Left

  • Front Right

  • Rear Left

  • Rear Right

• High-Level Inputs with ESX EPS® Error Protection System

• EPS® prevents error messages in the vehicle diagnostic system on compatible vehicles

• 4-channel low-level/RCA input via cable connector

• Low-level input sensitivity: 190 mV – 4.3 V

• High-level input sensitivity: 400 mV – 8.3 V

• Automatic power-on function via VOX or DC
  
  

Outputs

• 4 amplified speaker channels

• Stereo low-level/RCA output (L/R) via cable connector

• Stereo output, for example, for:

  • active subwoofers

  • additional mono power amplifiers

  • other amplifiers
    
    

Crossover Networks

• Separate filter options for front and rear

• High-pass filter (HPF): 80 Hz

• Low-pass filter (LPF): 80 Hz

• Slope: 12 dB/octave

• Front and rear filters can be switched on and off separately

• FULL / HP / LP Operating Modes
  
  

Features

• Ultra-compact nano-design

• Efficient Class D Technology

• Solid cast aluminum heat sink

• Automatic Power-On Function

• High-Level Inputs with EPS®

• RCA inputs and outputs via cable connectors

• Stereo RCA output for system expansion

• Suitable for high-resolution audio signals

• Start/Stop Ready

• ISO Plug+Play Connection

• 60 cm ISO Plug-and-Play Cable Set Included

• Suitable for boosting the power of front and rear speakers in many factory-installed radios
  
  

Dimensions

• Width: 90 mm

• Height: 35 mm

• Length: 80 mm