The LS50 is a two-way loudspeaker system, inspired by the LS3/5A and conceived to celebrate the 50th anniversary of KEF. Like the LS3/5A, the LS50 has been developed with the extensive application of the latest engineering techniques, along with meticulous attention to detail. It uses KEF's latest 5” mid-range and 1” high-frequency driver units in a compact two-way system. Extensive listening tests were performed to ensure the right engineering choices were made to achieve the best possible balance. Both systems could be described as “Engineers loudspeakers”, where the design has been determined by engineering parameters and sonic performance, rather than marketing requirements.
Rarely the case in such a compact design, the LS50 monitor delivers a rich, multi-dimensional ‘soundstage experience’ that is out of all proportion to its size. Patent-pending acoustic designs, together with state-of-the-art technologies from KEF’s latest flagship Blade loudspeaker, provide the ultimate studio experience – even in the smallest of spaces.
Design Two-way bass reflex
Drive units Uni-Q driver array:
HF: 25mm (1in.) vented
LF/MF: 130mm (5.25in.)
Frequency range (-6dB) 47Hz - 45kHz
Frequency response (±3dB) 79Hz - 28kHz
Crossover frequency 2.2kHz
Amplifier requirements 25 - 100 W
Sensitivity (2.83V/1m) 85dB
2nd & 3rd harmonics (90dB, 1m) <0.4% 175Hz-20kHz
Maximum output 106dB
Nominal impedance 8Ω (min. 3.2Ω)
Weight 7.2kg (15.8lbs.)
Dimension (H x W x D)
(with terminal) 302 x 200 x 278 mm
(11.9 x 7.9 x 10.9 in.)
The development of the LS50 was based on a highly technological approach. Simulation and measurement is used wherever possible to identify, quantify and resolve performance shortcomings. This philosophy is classic KEF and is one which has been consistently applied over the companies 50 year history. The recent maturity of numerical techniques, such as FEA and BEA, make the approach more effective than ever – especially when guided by critical listening and engineering intuition. Recent products such as Blade, R-series and now the LS50 are testament to the efficacy of this process.
The LS50 uses a central driver position and computer optimised acoustical damping to avoid exciting resonances due to standing waves. A combination of bracing on the symmetry planes and constrained layer damping within the enclosure construction is extremely effective at absorbing the driver vibration and effectively eliminates cabinet colouration due to wall radiation. The baffle design provides a smooth response over the entire forward region, reducing tonal variation in different listener positions and ensuring the most spacious sound with precise stereo imaging. The port design has a profile optimised to avoid turbulence with the accompanying distortion and bass compression. A flexible section in the port reduces resonant midrange output from the port.
It is rare to find a loudspeaker that offers this combination of clarity and neutrality. For KEF's LS50 Anniversary Model to do so for a penny under $1500/pair makes it even more remarkable. This thoroughbred both shows a clean pair of heels to the venerable LS3/5a and, within its limits of dynamic range and bass extension, will provide Class A sound for those with small rooms. Recommended. Highly. ...The KEF LS50 may be relatively affordable, but it offers superb measured performance.