Cambridge Audio has spent decades cultivating a reputation for what the British call "the great British sound," a voicing philosophy that prioritizes tonal honesty, wide bandwidth, and low listening fatigue over showy coloration. Their catalog spans the Edge flagship electronics, the CX and AX integrated amplifiers, the Evo all-in-one streaming systems, and a growing range of compact powered speakers. The L/R S sits at the accessible, space-conscious end of that lineup, a pair of active bookshelf speakers designed to deliver Cambridge's tuning to a desktop, a small living room, or a secondary system without the clutter of separates.
What follows is a deep technical breakdown of how these speakers are built, why each engineering decision was made, and what the specifications tell us about their intended use.
Core Concept and Topology
What kind of speaker is the L/R S?
The L/R S is a pair of active powered stereo speakers sold only as a matched left and right set, with Bluetooth as the sole wireless connection method. "Active" is the operative word. Unlike a passive bookshelf speaker that needs an external amplifier, the L/R S carries its own amplification inside the cabinets. That integration is the whole point. When the amplifier is designed and voiced together with the specific drivers it is driving, the engineer controls every variable in the signal path rather than hoping an owner pairs the speakers with suitable electronics. The result is a system tuned as one coherent object.
The "S" designation places it as the smaller, more compact expression of the L/R concept within the Cambridge Audio family, a model that trades outright scale for footprint and simplicity.
How is the left and right amplification split between the two speakers?
The system uses one primary speaker and one secondary speaker connected by a wired analog inter-speaker link. You can tell them apart by weight, the primary at 3.0 kg and the secondary at 2.6 kg. That difference reflects where the electronics live. The primary cabinet houses the input stage, the digital-to-analog conversion, the control electronics, and the connectivity, then feeds the secondary channel through the physical cable.
The choice of a wired analog link rather than a wireless connection between the two speakers is deliberate and audibly meaningful. A wired link guarantees perfect channel sync with zero latency and no compression between left and right, which preserves the stereo image and phase relationship that give recordings their sense of width and depth. Wireless speaker-to-speaker schemes can introduce timing artifacts. Cambridge sidesteps that entirely.
Amplification and Power
How much power does the L/R S produce and is that enough?
Each speaker produces 50 watts, for 100 watts total across the pair. In the context of a compact active speaker with a 3 inch woofer, that figure is well matched rather than modest. Power is only meaningful in relation to the load it drives and the room it fills. Fifty watts per side into a small, sealed-and-ported enclosure with an efficient driver is ample for nearfield desktop listening and comfortable for small to medium rooms. Because the amplifier is purpose-built for these exact drivers, there is no impedance guesswork and no headroom wasted on a mismatch.
Why does the L/R S use Class D amplification?
The L/R S uses Class D amplification because it delivers high efficiency, low heat, and a compact footprint, all of which are essential in a speaker where the amplifier must live inside the cabinet. Class D works by switching the output devices fully on or fully off at a high frequency, then filtering that switched signal back into an analog waveform. Because the transistors spend almost no time in their lossy linear region, very little energy is wasted as heat. That efficiency is what allows 50 watts per channel to fit inside a cabinet measuring only 134 by 226 by 180 mm without heatsinks the size of the speaker itself.
Modern Class D, which Cambridge has deployed across products up to and including its Edge and Evo ranges, has largely shed the harshness that plagued early implementations. The practical benefits here are cool running, reliability, and the ability to sit the amplifier immediately behind the drivers it feeds, shortening the signal path.
Drivers and Acoustic Design
What drivers does each L/R S speaker use?
Each speaker carries one 21mm aluminum dome tweeter and one 3 inch woofer, loaded by a rear reflex port. This is a classic two-way arrangement, with the tweeter handling the high frequencies and the woofer covering the midrange and bass. The two-way design is the right choice for a cabinet this size because it minimizes the number of crossover transitions in the audible band, keeping the presentation coherent.
Why an aluminum dome tweeter?
The 21mm aluminum tweeter is chosen because aluminum is a stiff, light material that stays rigid, or pistonic, well up into the treble. A tweeter dome that flexes rather than moving as a single piston introduces breakup modes that color the sound. Aluminum's high stiffness-to-mass ratio pushes those breakup modes higher in frequency, ideally beyond the region where the ear is most sensitive, so the tweeter's passband stays clean. The 21mm diameter is a small dome, which helps the tweeter disperse high frequencies widely rather than beaming them in a narrow cone, an advantage for a speaker likely used at close range on a desk where head movement is constant.
What does the 3 inch woofer and rear reflex port do?
The 3 inch woofer produces the midrange and bass, and the rear reflex port extends the low-frequency reach beyond what so small a driver could manage sealed. A reflex, or ported, enclosure uses a tuned opening that resonates at a chosen frequency. Below the woofer's natural roll-off, the port's output reinforces the bass, effectively borrowing extra low-end from the cabinet's air volume. The trade-off is that a ported design rolls off more steeply below the tuning frequency and, because the port is rear-firing, benefits from a little breathing room behind the speaker. Placing the L/R S too close to a wall will exaggerate the bass, so a few centimeters of clearance keeps the low end tight.
What is the frequency response and how should I read it?
The rated frequency response is 55 Hz to 24 kHz plus or minus 3 dB. That plus or minus 3 dB tolerance is the meaningful part. It tells you the speaker holds its output within a 6 dB window across that whole range, which is a genuinely useful specification rather than a marketing number pulled from the extremes of measurable output. The 55 Hz lower limit is honest for a 3 inch woofer in a compact port-loaded cabinet. It reaches into the upper bass and captures the fundamental of most vocals, guitars, and the body of a kick drum, while the deepest bass notes and the lowest synthesizer fundamentals sit below it. That is precisely why Cambridge provides a subwoofer output. The 24 kHz upper limit sits above the range of adult human hearing, confirming the aluminum tweeter's breakup is kept well clear of the audible band.
Connectivity and System Integration
What can I connect to the L/R S?
The L/R S accepts an RCA line input, an optical TOSLINK digital input, USB-C audio, and Bluetooth. That set covers analog sources such as a turntable with its own phono stage or a DAC, digital sources like a television or CD player over optical, and a direct USB-C connection from a computer for bit-accurate playback. The variety of inputs is what lets a single compact pair anchor a desktop, a bedroom, or a TV setup without additional boxes.
Which Bluetooth codecs does it support and why does that matter?
Bluetooth support includes SBC, AAC, aptX, and aptX HD. Codecs matter because they determine how much of the original signal survives the wireless trip. SBC is the mandatory baseline. AAC is the codec of choice for Apple devices and encodes efficiently. aptX reduces the audible compromise of Bluetooth by using more efficient coding, and aptX HD extends that to a higher-resolution transport, carrying more detail before the wireless link becomes the limiting factor. Having all four means the L/R S negotiates the best available option with whatever phone, tablet, or computer you use.
Does the L/R S support Wi-Fi or network streaming?
No, the L/R S does not include Wi-Fi or any network streaming. This is a deliberate scope decision. It keeps the product simple and reliable, and it positions the L/R S for people who stream from their phone over Bluetooth or feed it from a physical source. If integrated network streaming with a control app is a priority, the Evo range is where Cambridge Audio places that capability. The L/R S stays focused on being a clean, direct-connected pair.
Can I add a subwoofer?
Yes, the L/R S has a dedicated subwoofer output. Given the 55 Hz lower limit of the main speakers, this output is the intended path to full-range sound. Adding a powered subwoofer lets it handle everything below where the 3 inch woofers naturally give up, filling in the lowest octave for movies and bass-heavy music while leaving the mains free to concentrate on the midrange and treble they do best.
Control, Build, and Finishes
How do you control the L/R S without a display?
The L/R S has no display and is controlled by a BLE (Bluetooth Low Energy) remote. Omitting a screen keeps the cabinet clean and the cost focused on the audio path rather than the interface. BLE is chosen for the remote because it sips power, allowing long battery life, and maintains a stable link for volume, input selection, and EQ changes.
What do the EQ modes do?
The L/R S offers three EQ modes, Normal, Movie, and Voice. Normal is the reference voicing for music. Movie shapes the response to add impact and a sense of scale for film soundtracks. Voice emphasizes the midrange band where speech lives, improving dialogue clarity, which is especially useful when the speakers are paired with a television. These modes are applied in the digital domain before amplification, so they adjust the signal precisely without adding analog circuitry.
How big are the speakers and what finishes are available?
Each speaker measures 134 by 226 by 180 mm (5.3 by 8.9 by 7.1 inches), a genuinely compact footprint that suits a desk or a bookshelf. Finishes include Black, White, Blue, Green, Orange, and Real Walnut. The color range signals that Cambridge intends these to live in view as part of a room rather than hide in a rack, with the Real Walnut option nodding to traditional hi-fi cabinetry.
Where the L/R S Fits
The L/R S is the compact, direct, no-nonsense member of Cambridge Audio's active speaker family. It concentrates the brand's tonal priorities, honest bandwidth within its size, a clean aluminum tweeter, and a purpose-matched Class D amplifier, into a pair small enough for a desktop yet capable enough for a small room. It leaves network streaming and larger-scale bass to models above it, and in doing so it stays true to a single idea, that a carefully voiced active pair with the right inputs and a subwoofer output can be a complete and satisfying system on its own.
