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KEF LSX II vs Q Acoustics M20 HD Comparison

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KEF LSX II

Powered Bookshelf | 54-28k Hz

KEF LSX II
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Q Acoustics M20 HD

Powered Bookshelf | 55-22k Hz

Q Acoustics M20 HD Wireless Music System
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KEF LSX II KEF LSX II
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Q Acoustics M20 HD Q Acoustics M20 HD
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KEF LSX II
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Q Acoustics M20 HD
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KEF LSX II vs Q Acoustics M20 HD Speaker Comparison

In this review, we will be comparing LSX II and M20 HD, two Powered Bookshelf speakers from KEF and Q Acoustics. Being Powered speakers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them.

Let's have a brief look at the main features of KEF LSX II and Q Acoustics M20 HD first before getting into our more detailed comparison.

KEF LSX II Key Specs

  • 2-way Design
  • 200-watt RMS Integrated Amplifier
  • 11th Generation Uni-Q Driver
  • 0.75" Hard-Dome Tweeter
  • 4.5" Magnesium/Aluminium alloy Woofer
  • 54-28k Hz Frequency Response
  • 24-bit Max Depth / 384 kHz Max Sample Rate
  • Built-in 4.2 Bluetooth
  • App Control Feature
  • Weight:3.60kg
  • Dimensions (H x W x D): 240.0" x 6.1" x 7.1"( 240 × 155 × 180 mm )

Q Acoustics M20 HD Key Specs

  • 2-way Design
  • 128-watt RMS Integrated Amplifier
  • 0.875" Dome Tweeter
  • 5" Woofer
  • 55-22k Hz Frequency Response
  • 24-bit Max Depth / 192 kHz Max Sample Rate
  • Built-in 5.0 Bluetooth
  • Weight:5.10kg
  • Dimensions (H x W x D): 278.0" x 6-11/16" x 12-3/16"( 278.0 x 170.0 x 310.0mm )

In the following sections, we will get into more detail in order to better understand how the KEF LSX II and Q Acoustics M20 HD compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.


**This post contains affiliate links, and I will be compensated if you make a purchase after clicking through my links. As an Amazon Associate I earn from qualifying purchases.


Drivers

Both LSX II and M20 HD are 2-way speakers.

Driver KEF LSX II Q Acoustics M20 HD
Driver Setup 2-way 2-way
Tweeter 0.75-inch 0.875-inch
Midrange - -
Woofer 1 x 4.5-inch 1 x 5-inch

LSX II features a 0.75" Aluminum Hard-Dome Tweeter and 1 x 4.5" Magnesium/Aluminium alloy Woofer . On the other hand, the M20 HD features a 0.875" Dome Tweeter and 1 x 5" Woofer .

Frequency Response

LSX II has a frequency range of 54-28k Hz whereas M20 HD has a frequency range of 55-22k Hz. With a minimum frequency of 54Hz, the LSX II can go slightly deeper then the M20 HD's min frequency of 55Hz.

Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Bookshelf class in our database.

Low Frequency

Bookshelf Speakers

LSX II
M20 HD
Min
Average
Max
High Frequency

Bookshelf Speakers

KEF LSX II
Q Acoustics M20 HD
Min
Average
Max

None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.

Cabinet Type and Port Position

Both LSX II and M20 HD have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.

If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.

KEF LSX II  Port
KEF LSX II Port

Physical Specs

Size of a speaker can sometimes become an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare KEF LSX II's and Q Acoustics M20 HD's external dimensions. KEF LSX II has external dimensions of 240 × 155 × 180 mm ( 9.5 × 6.1 × 7.1 inch) whereas Q Acoustics M20 HD has external dimensions of 278.0 x 170.0 x 310.0mm ( 10-15/16 x 6-11/16 x 12-3/16inch) .

Q Acoustics M20 HD is clearly the larger of the two speakers. Its body is 15mm wider, 38mm taller and 130mm deeper than KEF LSX II.

Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited. The base surface area of the KEF LSX II is approximately 279.0cm2 / 43.2inch2 and base area of the Q Acoustics M20 HD is approximately 527.0cm2 / 81.7inch2. The LSX II requires 47% less surface area than the M20 HD which gives it a small advantage on placement in tight spaces.

Weight Comparison

The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The KEF LSX II weighs 3.60kg / 7.9lbs and the Q Acoustics M20 HD weighs 5.10kg / 11.2lbs. This makes the M20 HD 42% heavier than the LSX II.

Here is a comparison of how LSX II and M20 HD's weights compare with the average, max and min weights in Powered Bookshelf class.

Weight
All Bookshelf Speakers
KEF LSX II
Q Acoustics M20 HD
Min
Average
Max

What's in the Box of KEF LSX II?

Here are the items that are included inside the box of LSX II:
  • 2 Wireless powered speakers
  • Two 6.5-feet AC power cords
  • 10-feet Cat-6 interconnect speaker cable
  • Remote control
  • 2 AAA batteries
  • Quick Start Guide
  • Important Safety Information
  • Warranty Information
  • Maintenance Guide
  • What's in the Box of Q Acoustics M20 HD?

    Here are the items that come with the M20 HD:
  • Powered speaker
  • Passive speaker
  • 6-feet AC power cord
  • Remote control
  • 2 AAA batteries
  • 13-feet Speaker wire
  • 59-inch Optical digital cable
  • 2 Foam port plugs
  • Owners Manual

  • Reasons to choose KEF LSX II over Q Acoustics M20 HD Wireless Music System
    Low Frequency Response 54 Hz vs 55 Hz Generates deeper bass
    High Frequency Response 28k Hz vs 22k Hz Generates higher frequency
    App-Based Control Apple iOS, Android vs None Control the speaker via an app
    Height 240mm vs 278mm Easier to fit in smaller spaces
    Base Surface Area 279cm2 vs 527cm2 Takes less floor space
    Ethernet Connection Yes vs No High quality streaming over Ethernet
    USB Port USB-C (connects to your computer) vs No USB port adds flexibility
    HDMI Input ARC vs No Connect HDMI sources directly

    Reasons to choose Q Acoustics M20 HD Wireless Music System over KEF LSX II

    Woofer Size 5 inches vs 4.5 inches Larger woofer
    Price per pair* 599USD vs 1299USD costs less (*prices may change depending on the seller, location and time)
    RCA Connection Yes vs No Connection via RCA input
    KEF LSX II vs Q Acoustics M20 HD Specs Table
    Detailed comparison of specifications
    General KEF LSX II Q Acoustics M20 HD Wireless Music System
    Brand KEF Q Acoustics
    Speaker Type Powered Stereo Speakers Powered stereo speakers
    Frequency Response 54-28k Hz 55-22k Hz
    Amplifier
    Watts RMS (Continuous) 200-watt RMS 128-watt RMS
    Max Bit Depth 24-bit 24-bit
    Max Sample Rate 384 kHz 192 kHz
    Drivers
    Woofer Quantity 1 1
    Woofer Size 4.5" 5"
    Woofer Composition Magnesium/Aluminium alloy
    Woofer Surround Material Rubber n/a
    Tweeter Size 0.75" 0.875"
    Tweeter Type Hard-Dome Dome
    Aimable Tweeter No No
    Midrange Driver No No
    Firing Direction rear rear
    Physical Specs
    Height 240.0mm (9.4") 278.0mm (10.9")
    Width 155.0mm (6.1") 170.0mm (6.7")
    Depth 180.0mm (7.1") 310.0mm (12.2")
    Weight 3.60kg (7.9lbs) 5.10kg (11.2lbs)
    Enclosure Bass Reflex Bass Reflex
    Available Colors Carbon Black, Mineral White, Cobalt Blue, Lava Red, and Soundwave Black, White, Walnut
    Mounting Bracket No No
    Grille n/a Yes
    Moisture Resistancy No No
    Connections
    Aux Inputs 3.5mm 3.5mm, Stereo RCA
    USB Port USB-C (connects to your computer) USB-B
    Phone Input No No
    Subwoofer Output Wired mono-RCA
    Digital Input Optical Optical
    HDMI Input ARC No
    Headphone Jack No No
    Ethernet Port Yes No
    Other
    Parts Warranty 1 Year 2 Years
    Labor Warranty 1 Year 2 Years

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