KEF LS50 Wireless II Powered stereo speakers with Wi-Fi®, Bluetooth®, and Apple AirPlay® 2 (Crimson Red)

Audio Section
Network & Internet Integration
Bluetooth, Analog & Digital Inputs
Intuitive Control

Audio Section

24-Bit/384kHz DAC: The KEF LS50 Wireless II utilizes a 24-bit/384kHz DAC (digita-to-analog converter) for audiophile quality playback. The LS50 Wireless II supports digital music files up to 24-bit/384kHz, as well as MQA Decoding and DSD256. All sources are resampled to either 24-bit/96kHz PCM or 24-bit/192kHz PCM; depending on a wired or wireless connection between the LS50 Wireless II's two powered speaker.

• MQA (Master Quality Authenticated): MQA is a revolutionary end-to-end technology that captures and delivers master quality audio in a file that's small enough to stream or download. MQA lets you hear your streamed digital music files exactly like the way the artist intended you to hear it when it was approved in the studio.
• DSD (Direct Stream Digital): DSD is high-resolution digital audio format that uses a single bit to deliver a high resolution signal. Instead of sampling the information several thousand times a second, this single bit samples 2.8 million times a second to generate the audio signal. The result is still a Hi-Res audio signal that clean and pure.

Bi-Amplifier Configuration: The built-in amplifiers have been developed in-house by KEF. Each tweeter is driven by a 100W class A/B amplifier that delivers a smooth, incredibly detailed treble performance. Dedicated 280W class D amplifiers power the midbass drivers, for room-filling (up to 328 sq/ft), controlled sound up to 108db. The two powered speakers may be connected together either wirelessly or hard-wired.

• Wireless Mode: LS50 Wireless II is pre-paired at the factory for easy setup in wireless mode. The wireless transmission is totally independent of the local WiFi signal. The minuscule delay (2.9ms) between the primary and secondary speakers in this mode is automatically accounted for, through an equal delay applied to the primary speaker. The wireless connection re-samples all audio to 24-bit/96kHz. Wireless Mode has a range of 26'.
• Wired Mode: The wired interspeaker connection uses CAT-6 cable, plugged into the RJ45 sockets on the rear of the speakers. Cable mode must be enabled in the KEF Connect app settings menu. In this mode, all audio signals are resampled to 24-bit/192kHz. The included CAT-6 cable is 10' in length.

Digital Signal Processing: All aspects of the LS50 Wireless II's performance is aided by KEF’s proprietary Music Integrity Engine. This collection of unique Digital Signal Processing algorithms is optimized for the Uni-Q driver configuration, enabling it to deliver a perfectly timed performance, for better imaging and a tighter sound.

Metamaterial Absorption Technology (MAT): KEF teamed up with the Acoustic Metamaterials Group (AMG) to use Metamaterial Absorption Technology (MAT) in their LS50 Wireless II powered speaker. Metamaterials are specially developed structures that use existing materials in such a way that they exhibit new, desirable properties that are simply not found in naturally occurring substances. A truly revolutionary technology, MAT is a highly complex maze-like structure, where each of the intricate channels efficiently absorbs a specific frequency. When combined, the channels act as an acoustic black hole, absorbing 99% of the unwanted sound that comes from the rear of the tweeter, eliminating the resulting distortion and providing a purer, more natural acoustic performance.

12th Generation Uni-Q Driver Array: The LS50 Wireless II powered speaker utilizes KEF's patented 12th Generation Uni-Q driver configuration, in which the tweeter is mounted at the acoustic center of the midrange cone. With both acting as a single point source, the sound is dispersed widely and evenly throughout the listening area allowing you to experience superbly defined and perfectly balanced stereo imagery with a wide "sweet spot". Using simulation and analysis tools and decades of accumulated in-house knowledge, KEF engineers developed a 12th Generation Uni-Q driver array, with a new cone neck decoupler and motor system that is precisely shaped to reduce high-frequency distortion in the mid-frequency driver. The result is reduced coloration, less distortion and a sound that is more transparent and life-like than previously possible. The same can also be said of bass performance, where LS50 Wireless II exceeds the expectations of a modestly proportioned bookshelf and standmount speakers to deliver room-filling sound with deep, articulate bass.

• 1" Aluminum Vented-Dome Tweeter: The geometry of the tweeter dome matches that of the midrange cone to avoid disrupting the waveform. By smoothening high frequency response, this helps to account for the detailed and strikingly natural-sounding treble. The 1" aluminum vented-dome tweeter utilizes a Tangerine Waveguide to encourage the sound to radiate spherically for wider, more even dispersion so that everyone in the room enjoys the same superb sound quality. A large internal vent prevents potentially distorting high pressures from building up behind the dome in the critical vocal region, preserving all the nuance and fine detail of the original performance.
• 5.25" Aluminum Cone Woofer: The 5.25" woofer uses an Aluminum cone that is light, stiff, and smooth for natural midrange and midbass sound. As well as allowing the midrange cone its full extension, KEF's ingenious Z-flex surround guides the sound from the tweeter across the surround without any disturbance or secondary radiation. Treble response is clearer and sweeter.

Advanced Cabinet Design: From the precision molded curved baffle to the solid, reinforced cabinet, every inch of LS50 Wireless II has been designed to perform. Every aspect of LS50 Wireless II has been considered for acoustic benefits and from a design perspective. The low-diffraction curved front baffle is subtly mirrored by the gently radiused rear panel, where both the port exit and the speaker's inputs/outputs have been elegantly recessed and softened visually.

• Rigid Cabinet Bracing: The LS50 Wireless II’s extremely rigid cabinet is optimized for the best performance, with smooth curved surfaces that help radiate sound out across the baffle without any interference. Inside the cabinet, cross bracing and Constrained Layer Damping (CLD) combine to deaden internal vibrations. The result of such meticulous attention to detail is that LS50 Wireless II produces the lowest coloration of any speaker in its class.
• Robust Curved Baffle: LS50 Wireless II's baffle is engineered from an injection-moulded Dough Moulding Compound (DMC), usually found in the automotive industry. The LS50 Wireless II's low-diffraction, curved baffle is precision modelled around the Uni-Q driver array. It’s smooth curved surfaces help radiate sound out across the baffle without any interference from hard edges, which cause diffraction. The result is cleaner, more precise sound.
• Flexible Port Design: Using Computational Fluid Dynamics (CFD), the port flare and profile of LS50 Wireless II's patented off-set port is calculated to delay the onset of turbulence, and the flexible port walls prevent resonances from coloring the midrange. This leads to improved clarity, with exceptional depth and detail. Two foam port plugs are included to seal the cabinet if the bass is too "boomy" because of speaker placement.

Dual Subwoofer Outputs: For even more impact and bass extension, LS50 Wireless II features two mono-RCA subwoofer outputs, to connect a powered subwoofer (sold separately - see Accessories Tab). The KEF Connect App (for Apple iOS 14.0+ and Android OS 8.0+) on your compatible smartphone or tablet device allows you to set the subwoofer outputs' Low Pass Frequency (50 to 120 Hz), Gain (-10 to 10 dB), and Polarity (On or Off). You can also set the speaker's High Pass Frequency (50 to 120 Hz).

Mounting & Placement Options: The speakers should be placed on a flat and level surface that is free from vibration, such as the KEF S2 speaker stands (sold separately). The two speakers are distinguished between the Primary Speaker and the Secondary Speaker. By default, the Primary Speaker is the right channel and should be placed on your right hand side as you face the speakers, while the Secondary Speaker is the left channel and should be placed on your left hand side as you face the speakers.

• For the best stereo experience, soundstage and stable connection, place the speakers within 26' apart from one another.
• The optimum distance between the speakers and the listener will depend on how far the Primary Speaker and the Secondary Speaker are separated.
• Try to keep the same distance of the speakers to the listener so it forms an equilateral triangle.

Network & Internet Integration

Wired or Wireless Network Connectivity: The KEF LS50 Wireless II can be connected to your home network via a wired (Ethernet) or wireless (WiFi) connection. There is a RJ-45 Ethernet port (10/100Mbps) on the back of the speaker which allows for a hardwired connection. Built-in 2.4/5GHz dual-band WiFi (802.11 a/b/g/n/ac) allows the LS50 Wireless II system to connect wirelessly to your home network. This network connection allows support for the KEF Connect App, Apple AirPlay 2, and Chromecast Built-In; plus Roon-Ready. You can select between 3 audio streaming settings based on your home network.

• Hi-Fi (Hi-Fi quality): Always select this setting for the best audio quality. The highest quality depends on the music streaming service and your subscription.
• High (CD Quality): Select this setting when the speakers are in a crowded network and experiencing quality drop-outs.
• Normal (MP3 Quality): Select this setting when the speakers are in a crowded network and experiencing audio drop-outs.

Online Music Services & Internet Radio: The KEF LS50 Wireless II provides access to Amazon, Deezer, Qobuz, Spotify, Tidal, and vTuner through the KEF Connect App (for Apple iOS 14.0+ and Android OS 8.0+) on your compatible smartphone or tablet device.

• Amazon Music: Amazon Music has a growing selection of over 2 million songs is always ad-free and on-demand, with curated playlists, personalized stations and unlimited skips. Upgrade to Prime Music Unlimited, and enjoy 10 million songs, weekly new releases, and more.
• Deezer: With 43 million tracks, 100 million playlists, and a presence in 182 countries, Deezer literally covers the globe for its subscribers. Subscriptions start at $9.99/month, and include ad-free playback, premium audio quality, and more.
• Spotify Connect: The KEF LS50 Wireless II offers Spotify Connect support, so you can stream millions of songs from your portable device with ease. You will need to subscribe to Spotify Premium and have the Spotify App on your Apple iOS or Android smartphone, so you can stream Spotify to the LS50 Wireless II system. Spotify is a digital music service that gives you on-demand access to one of the largest music libraries in the world (over 15 million tracks and counting). Spotify makes it easier than ever to discover, manage, and share music with your friends. You can browse music by artist, album, track, or most popular; and create your own music library with customized playlists.
• TIDAL Connect: The integration of Tidal Connect will enable Tidal users to instantly select and wirelessly stream music to the LS50 Wireless II from within the Tidal app (for Apple iOS and Android OS). TIDAL is a global streaming service that offers over 30 million songs in high-fidelity CD sound quality. TIDAL has two pricing tiers; either $9.99 or $19.99 a month. Both pricing levels allow you to access TIDAL's entire music library. The $19.99 tier has the added benefit of high-fidelity sound at CD-level quality.
• Qobuz: Qobuz offers the biggest catalog of Hi-Fi and Hi-Res albums in the world, both for new releases and specialized genres. For hundreds of thousands of albums, Qobuz includes all the information you need to recreate the appeal of a real CD - the names of musicians, producers, lyrics (everything you need to know to appreciate your favorite albums). Qobuz offers MP3, CD, and Hi-Res quality subscriptions.
• Internet Radio (vTuner): You have the ability to access thousands of internet radio stations through vTuner and save your favorite presets for easy access. Supported Internet Radio formatted content includes MP3, AAC, Ogg Vorbis and MMS.

Chromecast built-in: Use the Google Home App (for Apple iOS 12.0+ and Android OS 6.0+) to enable Chromecast built-in. Chromecast built-in gives you access to hundreds of online music streaming services, internet radio, and podcasts. Chromecast built-in streams audio directly from the cloud, so you get the 24-bit/96kHz sound quality and the ability to enjoy crystal clear sound exactly the way the artist intended. Simply tap the Cast button from a Chromecast built-in compatible music app on your Apple iOS or Android OS device to start streaming to the KEF LS50 Wireless II speaker system. You can search, browse, play, skip, and turn up the volume directly from the music apps you know and love on your compatible smartphone or tablet. Chromecast built-in supports FLAC, WAV, AAC, and MP3 music files. While you cast your music, you can still use your smartphone to answer a call, play a game, send a text, and even leave the room - all without interrupting what's playing on the KEF speaker system.

• Music, Radio, & Podcasts: Chromecast built-in lets you play music from popular music services and search by artist, song, genre, album playlist, mood, or activity. You can also listen to your favorite internet radio stations and podcasts. Compatible music and internet radio apps include Tidal, Spotify, Pandora, TuneIn, iHeart Radio, YouTube Music, and more (subscriptions and fees will apply). You'll also be able to stream your favorite music, playlists, podcasts, and more that are stored on your Android (OS 4.4.2+) device to the LS50 Wireless II speaker. You cannot stream stored content on an Apple iOS device using Chromecast built-in. If you're on your laptop or computer, you can also cast any music streaming website through the Chrome web browser to the speaker.
• Multiroom Audio: Add more Chromecast built-in speakers throughout your home (sold separately - see Accessories Tab) to create a whole house audio experience. You can play the same Chromecast built-in compatible music app (like Tidal, Spotify, or Pandora) on all speakers or groups of speakers in different rooms of your home. You'll be able control the multiroom audio system from the Google Home app on your Apple iOS or Android device, or using the Google Assistant and your voice on a compatible Google Home device.
• Voice Control (Optional): Purchase a Google Home wireless speaker (sold separately - see Accessories Tab) and gain voice control of compatible Chromecast Built-in music apps. You'll be able to access a specific music app and then select a specific station or song using only your voice. You'll also have voice control over Play, Pause, Skip, & Volume. The LS50 Wireless II and your Google Home speaker must be connected to the same wireless (WiFi) network.

AirPlay 2: AirPlay 2 is an advanced and easy-to-use wireless multiroom audio platform for iTunes, Apple Music, and other compatible Apple iOS apps. With AirPlay 2 you can play any sound from your Apple iOS device (running iOS 11.4 or later) or Mac computer (running OS X 10.13.2) through the KEF LS50 Wireless II speaker system and other compatible AirPlay 2 speakers throughout your home. You can choose to play audio in one room, play the same audio in grouped rooms, or play the same audio in every room. If you are an Apple Music subscriber, you can even play different music in different rooms (you can control and group directly from Apple's Music App and Home app on your Apple iOS device). You can even ask Siri-enabled devices (like your Apple iPhone, iPad, or Watch) to control playback of your Apple Music on the KEF LS50 Wireless II. In addition, you can watch videos and movies from YouTube and Netflix on your compatible Apple iOS device or Mac computer with perfectly synced audio on the LS50 Wireless II speaker system.

UPnP (Universal Plug-n-Play): The KEF LS50 Wireless II is UPnP compatible, which enables you to play your digital music library stored on UPnP servers (such as a network server with integrated UPnP software,Windows PC, or Mac OS X computer) through the LS50 Wireless II speaker system. You can stream a variety of compressed, lossless, and high-res music files. UPnP file browsing can be carried out using the KEF Connect App (for Apple iOS and Android). The LS50 Wireless II supports streaming digital music files up to 24-bit/384kHz, as well as MQA Decoding and DSD256. Supported music file formats include - MP3, AAC, FLAC, WAV, AIFF, ALAC, WMA, DSD, MQA, LPCM and Ogg Vorbis.

Roon Ready: Roon is a feature rich music library and playback application that compiles all the music files available to your network and makes them easily available to play across the KEF LS50 Wireless II speaker system and other Roon enabled audio devices. Roon manages digital music files (including FLAC, WAV, AIFF, ALAC, and DSD) collected on hard drives and networked storage. It can also access your iTunes library, and optionally integrate with the Tidal music streaming service. Roon is available for mobile, laptop or desktop devices. When you open the Roon app, it will display your complete audio library together with its metadata and artwork along with the KEF LS50 Wireless II and all other Roon enabled devices. Simply select the music you wish to play and the LS50 Wireless II or Roon device in which you want to hear it on.

Bluetooth 4.2: With built-in Bluetooth 4.2 and support for wireless audio streaming (A2DP), you are able to wirelessly stream stored music, music apps, and other audio content from your Bluetooth enabled smartphone, tablet, laptop, or computer to the KEF LS50 Wireless II speaker system. With SSP (Simple Secure Pairing), Bluetooth source devices can be paired with a single press of a button and without entering a PIN code. Multiple devices can be paired with the LS50 Wireless II speaker system, but only one device can be connected and playing at a time. You'll still need to control music playback and view song/artist/album info from your Bluetooth source device.

• The KEF LS50 Wireless II does not support wireless Bluetooth audio transmission to a set of Bluetooth headphones.
• The KEF LS50 Wireless II speaker system does not support Bluetooth hands-free communication for making and answering phone calls.
• The LS50 Wireless II must be first connected to your local network before it can be used as a Bluetooth speaker.

Bluetooth, Analog & Digital Inputs

HDMI eARC: The KEF LS50 Wireless II is outfitted with a HDMI eARC jack for connection to your TV's HDMI eARC or ARC input, so you can playback your TV's audio signal through the LS50 Wireless II speaker system. The HDMI eARC jack supports 2ch PCM audio up to 24-bit/192kHz.

• The LS50 Wireless II's HDMI eARC jack must be connected to a TV's HDMI ARC or eARC input; it will not work with a standard HDMI input.
• The HDMI eARC jack does not support Dolby Digital, DTS, or other multi-channel formats.
• The HDMI input does not support video.
• The LS50 Wireless II must always be first connected to your local network before using the HDMI connection.

Optical & Coaxial Digital Inputs: The KEF LS50 Wireless II is equipped with two digital audio inputs. There is one optical (toslink) digital input and one coaxial (RCA) digital input. The optical digital input supports 2ch PCM audio up to 24-bit/96kHz, while the coaxial digital input supports 2ch PCM audio up to 24-bit/192kHz.

• The optical and coaxial digital inputs do not support Dolby Digital, DTS, or other multi-channel formats.
• The LS50 Wireless II must always be first connected to your local network before using the optical or coaxial digital inputs.

Analog Input: The LS50 Wireless II also features an analog stereo minijack (3.5mm) audio input. This is a line-level input (not a Phono input). If you want to connect a turntable, you'll need an external phono preamplifier (sold separately) or a turntable with a built-in phono preamp.

USB-A Input: There is a USB (Type-A) input that is used only for service purposes only. It does not offer media playback or charging.

Intuitive Control

KEF Connect App: The KEF Connect app (for Apple iOS 14.0+ and Android OS 8.0+) provides setup and control of the LS50 Wireless II system from your compatible smartphone or tablet device. The KEF Connect app also gives you access to a variety of online music service and internet radio stations.

• Wireless Setup: The KEF Connect app allows simple and quick connection of the LS50 Wireless II to your home's wireless network router.
• Online Music Services: The KEF Connect app provides access to Amazon HD, Deezer, Qobuz, Spotify, Tidal, and vTuner.
• Playback Control: From the app, you can control playback volume, and input source selection.
• Audio Optimization: The app lets you optimize your listening experience through its EQ settings; allowing you to adjust the output of the speaker to better suit the room and your personal taste.
• Timers & Alarms: The app also lets you customize settings such as sleep timer, auto-wake up source, and child lock

IR Remote: The included IR remote provides basic wireless operation of the KEF LS 50 Wireless II speaker system. The IR remote provides the following control functions - Power On/Off, Source Selection, Volume Up/Down, Mute, Play/Pause, and Previous/Next Track.

Top-Panel Controls: Top-panel capacitive touch controls on the Primary Speaker (Right) include Power On/Off, Source Selection, Volume Up/Down, and Mute.

EQ Settings: For the best audio performance, apply sound settings from the KEF Connect app according to your listening area. EQ settings include - Desk Mode (-10 to 0 dB), Wall Mode (-10 to 0 dB), Treble Trim (-4 to 4 dB), Phase Correction (On or Off), Bass Extension (L/M/H), High Pass Frequency(50 to 120Hz), Sub Out Low Pass Frequency (40 to 240Hz), Sub Gain (-10 to 10 dB), and Sub Polarity (On or Off)

Auto Firmware Updates: Automatic firmware updates are done over your home's local network using the KEF Connect app (for Apple iOS 14.0+ and Android OS 8.0+).