SKU: 88668798655

ESX QM-FOUR - 4 Channel Amplifier

Sale price$152.99 Regular price$169.99
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Description

ESX QM-FOUR - 4 Channel AmplifierSpecifications 4 Channel Class D Mini Digital Amplifier 4 x 52 90 Watts RMS @ 4 2 2 x 180 Watts RMS @ 4 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 Dimensions 216 x 39 x 84 mm Efficiency up to 86% Features Efficient Class D Amplifier with ultra compact dimensions Heavy die cast Heatsink with perfect cooling characteristics Auto Turn On Function High

Specifications

  • 4-Channel Class D Mini Digital Amplifier
  • 4 x 52/90 Watts RMS @ 4/2 Ω
  • 2 x 180 Watts RMS @ 4 Ω 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
  • Dimensions 216 x 39 x 84 mm
  • Efficiency up to 86%

Features

  • Efficient Class D Amplifier with ultra-compact dimensions
  • Heavy die-cast Heatsink with perfect cooling characteristics
  • Auto Turn-On Function
  • High Level Inputs with Error Protection System (EPS)
  • Start/Stop Ready
  • Compact Bass Remote Controller
  • RCA Inputs & Outputs (via Molex)
  • Clipping LED

 The approximately palm-sized 2-channel mini power amplifier QUANTUM 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 QUANTUM 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-ONE monoblock is not only visually the perfect play partner to match the QM-FOUR. If a separate woofer is also to be fired, its area of application is clearly defined. With a full 360 watts RMS at 2 Ω, sufficient steam is provided, and the bass level can even be conveniently adjusted using the remote control.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 88668798655

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AMAZON CUSTOMER
Lexington, US
★★★★★ 5
plug and play ...fast ...hi performance... same as higher price
plug and play ...fast ...hi performance... same as higher price
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 16, 2026
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Verified Purchase
H. T.
Belleville, US
★★★★★ 5
premium feel in the hand.
Can't really say whether it's that good or not elecronics wise since I didn't test it but it works like it's supposed to. Meanwhile, the housing oh man. It's premium. It feels like hard aluminum or something, very nice. Edges are rounded too with just the right sharpness like a macbook. Others would've been plastic. This is really nice for the price and if the specs really are 10Gbps, that's really good because most in this price range is 5Gbps.
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Reviewed in the United States on March 2, 2026
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Amazon Customer
Los Angeles, US
★★★★★ 1
Failed to support desktop PCs with USB 3.2 Gen 2 ports
Does not work with my HP mini PC with USB 3.2 gen 2 ports - when connecting USB portable SSDs to the hub. You won't believe it, but many USB 3.2 Gen 2 hubs only support laptops not desktop PCs (except hubs that have dedicated power supply for higher power USB devices e.g. SSD/HDDs) when connecting USB portable SSDs to the hub. We need a major fix from many of the USB hub vendors so these products can work with desktop PCs that have USB 3.2 Gen 2 ports. Workaround: Just directly connect the USB portable SSD to the PC instead. If you need more USB ports, pick up a good old USB 3.0 hub. They're working correctly with portable USB SSDs when working with desktop PCs. (You'd need a powered USB hub if you're connecting 2 or more portable SSDs - do your own calculation: 5V - 1A per SSD/HDD).
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Reviewed in the United States on November 2, 2025
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Anonymous
Phoenix, US
★★★★★ 5
Works out of the box!
Set name: Space Gray
Day 1, the item works out of the box with various accessories such as a scanner and to connect older devices like a mouse and keyboard. For the price, this item is fantastic and has 2 usb ports, 2 usb-c (lightning) ports, an HDMI port, a micro sd card port, and an SD card port. Amazing product. If it breaks anytime soon, will update the review.
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Reviewed in the United States on June 9, 2026
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Alex
Port Orchard, US
★★★★★ 5
Your laptop just got an upgrade
Set name: Dual HDMI Adapter
Switched from a desktop to a laptop for work and missed my dual monitor setup badly. This device fixed that. Easy software install, works exactly as advertised. 10/10 if you need multi-monitor support on a laptop.
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Reviewed in the United States on June 2, 2026

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