KEF LSX II

What it does

• Plays as one wireless pair from a phone, or from a TV over HDMI ARC
• Streams with AirPlay, Google Cast, and Bluetooth after a Wi-Fi setup
• Puts a 19 mm dome and a 115 mm cone in each speaker
• Takes optical, USB-C, and a 3.5 mm line input on the primary speaker

The pair you receive

This listing is one Carbon Black pair of KEF LSX II powered speakers. It is sold as a set, not as a single speaker, and it is not the LSX II LT. Stands, desk pads, and wall brackets are extra. A music subscription is not included.

Setup uses the KEF Connect app on a Wi-Fi network. The manual says the speakers must join that network before Bluetooth, HDMI, optical, USB, or the auxiliary input will play. Each speaker has its own power inlet.

Each speaker uses a Uni-Q array: a 19 mm (0.75 in) aluminium dome and a 115 mm (4.5 in) magnesium/aluminium alloy cone. Amplifier output per speaker is 70 W for the low frequencies and 30 W for the high frequencies, both Class D. Maximum SPL is 102 dB measured at 1 m. Frequency range (−6 dB), measured at 85 dB/1 m, is 49 Hz to 47 kHz. Frequency response (±3 dB), measured at 85 dB/1 m, is 54 Hz to 28 kHz. Both depend on the EQ setting. Operating power consumption is 200 W for the system. Standby is under 2.0 W. The 200 W figure is power draw, not amplifier output.

The two speakers link wirelessly and resample every source to 48 kHz/24-bit PCM. The included 3 m interspeaker cable raises that link to 96 kHz/24-bit PCM. Keep them within 8 m on the wireless link. A shielded Cat-6 cable can run up to 10 m. That longer cable is not in the box. The primary speaker is the right channel by default. The app can swap left and right.

Inputs on the primary speaker are HDMI ARC, TOSLINK optical, USB-C, analog 3.5 mm, an RJ45 network port, and an RJ45 interspeaker port. The secondary speaker has power and the interspeaker port. The output is an RCA subwoofer jack. A subwoofer and an RCA cable are not included. HDMI needs the TV set to PCM, and the speakers accept HDMI CEC so the TV remote can change volume. The specification table lists optical up to 96 kHz/24 bit, USB-C up to 96 kHz/24 bit, HDMI up to 48 kHz/16 bit, and network audio up to 384 kHz/24 bit. The USB chapter of the same manual says a maximum of 192 kHz/24 bit. HDMI, optical, USB, 3.5 mm, and Ethernet cables are not in the box.

There is no phono preamp and no headphone jack. The analog input is 3.5 mm and expects a line-level source, such as a turntable that already has a phono stage. The Technics SL-1500C on this shop uses RCA outputs. It does not plug into this pair with the cables in either box.

The specification lists AirPlay, Google Cast, Roon Ready, UPnP, and Bluetooth 4.2. Streaming services named in the manual are Spotify via Spotify Connect, Tidal via Tidal Connect, Amazon Music, Qobuz, Deezer, QQ Music via QPlay, internet radio, and podcasts. One setup chapter still says Roon Ready is coming. Availability depends on the service and the country. Those accounts belong to the buyer. KEF Connect is the setup and EQ app. Network formats in the specification are MQA, DSD, FLAC, WAV, AIFF, ALAC, AAC, WMA, MP3, M4A, LPCM, and Ogg Vorbis.

Wi-Fi is IEEE 802.11a/b/g/n/ac, IPv4 and IPv6, on 2.4 GHz and 5 GHz. The manual recommends a 5 GHz network for hi-resolution streaming. Power is 100–240 VAC, 50/60 Hz, with a cable for each speaker.

Size per speaker is 240 × 155 × 180 mm, height by width by depth, 9.5 × 6.1 × 7.1 inches. Weight for the set is 7.1 kg, 15.6 lb. Rubber feet are on the bottom of each speaker. A 1/4-20 threaded hole takes an optional mount.

The box contains two speakers, a remote control with two AAA batteries, a 3 m interspeaker cable, two 2 m power cables, a quick start guide, safety information, warranty information, and a fabric cleaning guide. The printed warranty sheet is KEF’s. This shop does not add its own warranty. A dealer’s return window is not this shop’s policy.

Specs

Drivers, frequency, connections, size, weight, and the box list are from the KEF LSX II user manual, 2025 R02. The pair you receive is the Carbon Black set. Studio photo shows the listing.