I was truly impressed by the KEF LS50 Meta speakers. They offer exceptional midrange clarity and treble precision, thanks to their Uni-Q driver and acoustic metamaterial technology, which reduce resonance and enhance dispersion. The soundstage and spatial accuracy are outstanding. However, the bass can be less impactful without some adjustments. Using the included port plugs helps improve bass definition and speed. Proper setup, including stand height and speaker angling, is crucial for the best performance. The main drawbacks are the softer bass and the need for meticulous positioning to achieve optimal sound.
Contents
Intro
KEF celebrated its 50th anniversary with the construction of the LS50 monitors, which, along with designs such as Muon and Blade, became the showcase of this British brand. Eight years have passed since then, but the “Fifties” are still the apple of the eye of the engineering team led by Jack Oclee-Brown. This project has, for example, a wireless version (Wireless) and the Meta, which has just been launched. Where did this intriguing name come from and what does the new sound like?
Construction & Design
From the outside, not much has changed: the bass-reflex port in the upper right corner, now more oval, has had its corner holes removed. The front remains the same with a characteristically curved plastic wall, featuring a Uni-Q (12th generation) loudspeaker. This 13 cm unit simulates a point sound source and reproduces most of the acoustic spectrum.
In the center is a metal dome, surrounded by the Tangerine Waveguide with nine “leaves” for wide dispersion. The aluminum-magnesium mid-woofer has nine ribs to eliminate standing waves and shift mechanical resonances. Similar to the original LS50, the speaker has a Z-FLEX suspension to minimize diffraction.
KEF LS50 Meta Front View
The key changes in the new version of the “fifty” concern the Uni-Q unit, though not visible from the outside. The most significant update involves the use of acoustic metamaterial developed by the Acoustic Metamaterials Group (AMG). In KEF monitors, this metamaterial forms a flat, two-layer ABS plastic disc with 30 miniature quarter-wave resonators, each tuned to a different frequency.
This labyrinthine element’s purpose is to optimize the tweeter’s working conditions by suppressing the sound wave radiated by the back of the dome. Other changes within the Uni-Q loudspeaker, driven by the MAT system, include a modified tweeter magnetic system, a strengthened collar supporting the dome’s suspension, and a higher shorting ring in the mid-woofer’s magnetic system. These updates are reflected in the new, redesigned crossover, separated into two plates and made of high-quality components.
The MDF housing of the “fifty” has not changed, but its design remains impressive. The interior is strongly damped with foam and features cross-reinforcement with two plates intersecting at right angles. These plates have openings for airflow, supporting the Uni-Q loudspeaker and are connected to the walls using an elastic mass. Each solution used in this project is thoroughly thought out, aiming for the acoustic optimization of the entire structure.
KEF LS50 Meta Sound Test
One of the first things I noticed was the natural timbre and the extraordinary homogeneity of the new KEF’s sound at different points/places in the room. I could not hear any color changes when I got up from the sofa or walked around it. Such favorable directional characteristics are ensured by Uni-Q units that act as point sound sources. This naturally affects the perception of the stage – the coherence of the sound is so good that it forms a kind of continuum in which something like a single loudspeaker does not seem to exist.
The LS50 Meta perfectly conveys the midrange, reproducing the full, realistic decay of the instruments. The midrange is natural, free from harsh or dry sounds. This is undoubtedly the merit of the well-filled lower sub-range in this part of the band. It is true that initially in some recordings (e.g. Lunatic Soul from the album “Through Shaded Woods”, FLAC 24/44.1) the sound of the middle registers was accompanied by a slight haze, and muffled timbre, but after clogging the bass reflexes (see later) the impression is disappeared. Especially jazz recordings (eg the album Ivan Kapec 5tet “Crta”; FLAC 24/96) revealed an extraordinary openness, directness of the mid-range, and the energy located there.
The LS50 Meta excels in conveying the midrange with realistic instrument decay and natural tones, free from harshness or dryness. This clarity is due to the well-filled lower sub-range in this part of the band. Initially, some recordings (e.g., Lunatic Soul’s “Through Shaded Woods”, FLAC 24/44.1) had a slight haze and muffled timbre in the midrange, but this was resolved by clogging the bass reflexes. Jazz recordings (e.g., Ivan Kapec 5tet’s “Crta”; FLAC 24/96) showcased the midrange’s extraordinary openness, directness, and energy.
The LS50 Meta does have some weaknesses. In my opinion, the bass is less convincing. The low tones don’t extend too low, which is expected for small monitors, but their soft nature and lack of a hard attack may not appeal to everyone. The bass-reflex ports seem to contribute to this issue. However, plugging the holes with the included sponge plugs helped. This adjustment slightly reduced the volume but improved the bass’s value, rhythm, and contour.
- LS50 Meta features KEF's breakthrough Metamaterial Absorption Technology (MAT) reducing unwanted sound from the rear of...
- Features KEF'S 12th Generation Uni-Q Driver proving a 40% increase in smoothness over the previous version.
- THD 0.07%, Driver Performance Optimisation for enhanced sonic performance, less distortion and reduced coloration
- Frequency range (-6dB) - 47 Hz - 45 kHz
- Available in four stunning finishes: Cabon Black, Mineral White, Titanium Grey, and Royal Blue Special Edition
The effect of using the sponge plugs in the bass-reflex ports was so beneficial that I kept them in until the end of the listening session. With the plugs in, the KEFs sounded closer to my ATC SCM 7 monitors (which have closed housings), matching their transparency and surpassing them in creating spatial phenomena. The manufacturer anticipated that under certain conditions, it might be better not to fully plug the BR holes but to partially reduce them by removing the plugs. This approach means the bass loses some abundance but gains in hardness and speed, which seems reasonable. With the ports open, I didn’t notice a slowdown in the bass, but the lack of a hardened attack did lead to a loss of precision.
Joining the midrange with the treble is perfect on the LS50 Meta. Both ranges blend seamlessly, creating a “continuum” effect. The tweeter tuning plays a crucial role in this, offering clean and detailed highs without being overly clinical or harsh. The treble is well-balanced, providing clarity in the mid/lower sub-range and a more restrained presentation in the highest sub-range, avoiding an overly bright or airy sound.
The soundstage is another standout feature of the LS50 Meta. In a 14-square-meter room, the speakers create a precise and expansive stage, extending clearly in front of and behind the speakers. The depth and layering of the soundstage are highly convincing, adding to the overall precision and high-class performance of these monitors.
KEF LS50 Meta back side view
Setting up the LS50 Meta is crucial for optimal performance. While the transducers offer favorable directional characteristics, careful positioning is essential. The height of the stands should match the listener’s ear level. On my 60 cm high stands, the drivers were lower than my ears; raising them by 10 cm provided more open treble and better focus. Angling the speakers at 45 degrees to slightly see the internal walls from the listening position further enhanced the soundstage, making the space more suggestive. Attention to these details can significantly improve the listening experience.
KEF LS50 Meta Video Review
KEF LS50 Meta Specifications
- Model: LS50 Meta
- Design: Two-way bass reflex
- Drive units: Uni-Q Driver Array: HF: 25 mm (1 in.) vented aluminum dome with Metamaterial Absorption Technology, MF/LF: 130 mm (5.25 in.) aluminum cone
- Crossover frequency: 2.1 kHz
- Frequency range: (-6dB) 47 Hz – 45 kHz
- Typical in-room bass response (-6dB): 26 Hz
- Frequency response (±3dB): 79 Hz – 28 kHz
- Harmonic distortion (90dB, 1m): <0,4% 175 Hz – 20 kHz, <0,1% 300 Hz – 10 kHz
- Maximum output: 106 dB
- Amplifier power (recommended): 40-100 W
- Nominal impedance: 8 Ω (min. 3,5 Ω)
- Sensitivity: (2.83V/1m) 85 dB
- Weight: 7.8 kg (17.2 lbs.)
- Dimensions: (HWD per speaker) 302 x 200 x 280.5 mm (11.9 x 7.9 x 11.0 in.)
You can download & view the manual here->KEF LS50 Meta Manual
Final Verdict
Great speakers just melt away, leaving you with just the music. The primal voice, the perfectly executed layers of instruments that you can get lost in, sound so clear that it’s as if the artist is right there with you. This is what great speakers with the best technology can provide.
Is KEF LS50 Meta good?
KEF's Uni-Q designs tend to image well by their very nature, and these speakers are no different. The LS50 Meta generates an expansive and tightly focused soundstage where the instruments are layered convincingly. We're also impressed by the image's stability when the music gets demanding.
How loud are KEF LS50 Meta?
On the subject of listening volumes and 86db being loud... Yes, that is a fairly loud volume, but just as we discuss power in power amplifiers, 86db is average, which means that some sounds will be louder, and that means that it's possible to push speakers into distortion for brief passages.
Where are KEF LS50 Meta made?
'Designed and engineered in the UK, Made in China' was written on the serial number panels on the speakers' bases.
Crackling Sound was created to provide straightforward, unbiased reviews of audio products, catering to those who want excellent sound without delving into complex audiophile terms. I aim to simplify the decision-making process for my readers.
As an audio enthusiast and self-builder for over 20 years, I ensure my reviews are honest, highlighting both advantages and disadvantages. I conduct sound tests to deliver comprehensive and reliable information about various audio devices. My extensive experience in DIY projects, experimenting, installing, and using high-end audio gear helps me provide thorough and comparative reviews.