KEF LSX II Wireless Speakers | Ex-Demonstration

The KEF LSX II is one of the most complete compact wireless speaker systems available — a fully active, fully connected stereo pair that delivers KEF's celebrated Uni-Q® point-source acoustic engineering alongside 200W of dedicated Class D amplification, a comprehensive suite of wired and wireless connectivity, and native support for every major streaming service, in two cabinets of genuinely modest physical footprint. This listing is for ex-demonstration units — speakers that have served as in-store demonstration stock at our Norwich showroom, fully inspected and presented in near-new condition, available now at a reduced price.

11th Generation Uni-Q® Driver Array

The LSX II is built around a specially designed version of KEF's 11th generation Uni-Q® driver array — a 19 mm aluminium dome tweeter mounted at the acoustic centre of a 115 mm magnesium/aluminium alloy cone, in the coincident point-source arrangement that defines KEF's loudspeaker philosophy. This Single Apparent Source geometry ensures that treble and midrange radiate from precisely the same point in space — producing a soundstage of exceptional width and depth from a cabinet of remarkably modest dimensions, and a listening sweet spot far wider and more stable than a conventional two-way design of equivalent size can deliver.

Each driver is powered by its own dedicated amplifier channel: 70W Class D for the bass/midrange driver and 30W Class D for the tweeter — 100W per speaker, 200W per pair. The amplifier channels are precisely matched to their drivers and governed by KEF's Music Integrity Engine DSP platform, which applies bespoke algorithms developed specifically to optimise the Uni-Q® driver's performance — ensuring that the relationship between amplification, crossover, and driver is as precisely calibrated as KEF's Reference-class designs demand.

The two-way rear-ported bass reflex alignment extends frequency response to 49 Hz at −6 dB, with a maximum output of 102 dB — figures that place the LSX II's acoustic capability well beyond the reach of most wireless speakers at any price.

Music Integrity Engine

The Music Integrity Engine coordinates all of the LSX II's acoustic and electronic systems via KEF's bespoke DSP algorithms — managing crossover operation, driver linearisation, and the Room EQ system, which provides Normal and Expert modes with compensation for wall, free-standing, and desktop placement. A dedicated RCA subwoofer output is provided on the primary speaker for those who wish to extend bass performance further — the KEF KC62 Subwoofer pairs particularly cleanly with the LSX II given its compact dimensions and force-cancelling low-distortion bass character.

Wireless Connectivity and Streaming

The LSX II supports Wi-Fi (IEEE 802.11a/b/g/n/ac, dual-band 2.4 GHz and 5 GHz), Apple AirPlay 2, Google Chromecast, Bluetooth 4.2, and UPnP compatibility for music server and NAS integration. The system is Roon Ready. The KEF Connect app provides native access to Spotify Connect, Tidal Connect, Amazon Music, Qobuz, and Deezer — as well as Internet Radio — from a single interface on iOS or Android. For music files up to 24-bit/48kHz the inter-speaker connection is entirely wireless; a linking cable is supplied for high-resolution streaming above that threshold, with network streaming supporting PCM up to 24-bit/384kHz, DSD, and MQA.

Wired Connectivity

The primary speaker carries HDMI ARC for direct television connection, USB Type-C supporting audio up to 24-bit/192kHz, TOSLINK optical accepting up to 24-bit/96kHz, a 3.5mm analogue auxiliary input, and RJ45 Ethernet for a wired network connection. This breadth of wired connectivity makes the LSX II equally convincing as a desktop system connected to a laptop, a living room system connected to a television, or a dedicated music system driven from a network streamer or NAS.

Technical Specifications

Who Is It For?

The LSX II is for the listener who wants a genuine high-resolution music system — with streaming capability, acoustic performance, and connectivity breadth to justify that description — in the smallest possible footprint, and at a price that reflects the ex-demonstration status of these particular units. It suits desks, bookshelves, and sideboards equally; connects to televisions, laptops, and virtually any network streaming source; and delivers a stereo presentation that separate systems at this price point struggle to match. Those who want to explore the full-price LSX II or compare it to KEF's wider active speaker range — including the KEF Blade Meta at the top of the passive range — are welcome to do so at our Norwich showroom. The KEF KC62 Subwoofer extends the LSX II's bass performance for those who want a full-range system whilst retaining a compact overall footprint.

Buying from Martins Hi-Fi

Martins Hi-Fi has been in Norwich since 1968. Elizabeth Gould runs the business today, and we stock only brands we have heard properly and stand behind.

These ex-demonstration LSX II units are available to discuss at our Norwich showroom — we can confirm condition, finish availability, and answer any questions about what is included before you commit. When you get in touch, you'll be speaking with Dave, Chris and Tim — experienced specialists who can advise on this product and your whole system.

Contact us at info@martinshifi.co.uk, call 01603 627010, or WhatsApp on 07554 687137. You can read more about how we work on our Why Martins Hi-Fi page. We are at 85–91 Ber Street, Norwich, NR1 3EY.