Cambridge Audio has spent decades building a reputation as one of Britain's most pragmatic audio houses, a company whose engineering ethos leans toward transparency, measured performance, and thoughtful system integration rather than flashy gimmickry. From the Azur and CX component lines to the Edge flagship series and the StreamMagic streaming platform, the brand has consistently pursued what it calls "great British sound," a philosophy that favors low distortion, wide bandwidth, and a lack of editorializing coloration. The L/R M sits at the intersection of two of Cambridge Audio's strongest competencies: streaming and amplification packaged together in a single, self-contained active loudspeaker.
For the experienced enthusiast, the appeal here is a fully integrated, room-friendly system that dispenses with separate amplifiers, DACs, and streamers while retaining serious connectivity and the StreamMagic Gen 4 platform. This deep dive breaks down every meaningful design decision, from driver topology to power supply behavior, and explains the reasoning behind each one.
Core Concept and Design Philosophy
What exactly is the Cambridge Audio L/R M?
The Cambridge Audio L/R M is a pair of active powered stereo streaming speakers sold as a matched pair, meaning each cabinet contains its own amplification, digital processing, and driver complement, and the two units are designed and calibrated to work together as a single stereo system. Unlike a passive speaker that requires an external amplifier, the L/R M integrates everything: streaming source, digital-to-analog conversion, signal processing, and Class D power amplification. The "L/R" designation refers to left and right, and the pair is asymmetrical by design, with a primary speaker that houses the bulk of the electronics and connectivity and a secondary speaker that receives audio and control data over a wired link.
This architecture reflects a deliberate philosophy. By controlling the entire signal chain from source to driver, Cambridge Audio can tailor the amplifier, DAC, and DSP to the specific drivers and cabinet, eliminating the guesswork and impedance mismatches inherent in mixing separate components.
Why is one speaker the primary and the other the secondary?
The primary speaker carries the streaming engine, input connectivity, and processing, while the secondary speaker acts as a partner that receives its signal through a wired inter-speaker link. This is why the two cabinets differ in weight, with the primary at 6.2 kg and the secondary at 5.4 kg, the difference accounting for the additional electronics housed in the primary unit. Concentrating the brains in one enclosure simplifies the system, reduces duplicated circuitry, and keeps the signal path coherent between channels.
Amplification and Driver Topology
How much power does the L/R M produce and what amplifier class does it use?
Each speaker delivers 150 watts, for a combined 300 watts total per pair, using Class D amplification. Class D is a switching topology in which the output devices operate as high-speed switches rather than in the linear region, dramatically improving efficiency and reducing heat compared to Class A or Class AB designs. That efficiency matters enormously in a compact active speaker, where dissipating large amounts of waste heat inside a small sealed cabinet full of sensitive electronics would be impractical. Class D lets Cambridge Audio pack substantial power into a small enclosure while keeping thermal stress low, which improves long-term reliability and allows for higher sustained output without compression.
Because the amplifier is matched to known driver loads inside a controlled system, the designers can optimize the output stage precisely rather than building an amplifier that must tolerate any arbitrary speaker impedance. This is one of the quiet advantages of active design: the amplifier and driver behave as a single engineered unit.
What is the driver configuration in each speaker?
Each speaker uses a three-part driver array: one 28mm tweeter for high frequencies, two 4 inch woofers for midrange and bass, and two 4.75 inch side-mounted force-cancelling passive radiators to extend low-frequency output. The 28mm tweeter handles the treble region, and the two 4 inch woofers cover midrange and upper bass in a configuration that distributes cone area across a pair of drivers rather than relying on a single larger unit. Splitting the mid-bass duties between two smaller woofers keeps cone excursion under control and can improve dispersion and transient response relative to one bigger, heavier driver.
How do the side-mounted passive radiators improve bass?
The two 4.75 inch passive radiators are mounted on the sides of each cabinet and are described as force-cancelling, which means they are positioned to counteract each other's mechanical reaction forces so the cabinet stays acoustically inert. A passive radiator is an undriven diaphragm that is set into motion by the pressure changes created inside the sealed cabinet by the active woofers. It behaves somewhat like a ported design, extending low-frequency output, but without the port noise and turbulence that can accompany a tuned vent. Because these radiators sit on opposing side panels, their reaction forces largely cancel, which reduces cabinet vibration that would otherwise smear detail and add coloration. The audible benefit is deeper, cleaner bass from a small cabinet with a quieter, more stable enclosure.
What frequency range does the L/R M cover?
The L/R M reproduces from 40 Hz to 24 kHz within a plus or minus 3 dB window, which is the standard way of expressing usable, reasonably flat bandwidth. The 40 Hz lower limit indicates genuine low bass extension for a speaker of this physical size, made possible by the passive radiator loading and DSP-managed drivers. The 24 kHz upper figure extends beyond the nominal limit of human hearing, ensuring the treble remains flat and unforced well past the audible band. The plus or minus 3 dB tolerance tells you how tightly the response holds across that range, and a tighter window generally corresponds to a more neutral, predictable tonal balance.
Power Supply and Signal Processing
How is DSP used to shape performance?
The L/R M applies digital signal processing to actively manage crossover behavior, driver protection, and room correction. In an active speaker, the crossover that divides frequencies among the tweeter, woofers, and radiators is implemented in the digital domain before amplification, rather than with passive components after the amplifier. This allows far more precise control over slopes, phase alignment, and time correction between drivers than a passive network could achieve, and it does so without the insertion losses and component tolerances of inductors and capacitors in the signal path. DSP also enables the Room Optimisation and EQ modes, letting the speaker adapt its output to compensate for placement near walls or corners.
Does the L/R M offer room correction and EQ without a display?
Yes, the L/R M includes Room Optimisation and multiple EQ modes even though it has no onboard display, with control handled through the app and a Bluetooth Low Energy remote. Room boundaries reinforce bass, so a speaker placed close to a wall or in a corner will typically sound heavier in the low end. Room Optimisation counteracts this by adjusting the low-frequency output to suit placement, restoring a more even balance. The absence of a display keeps the front baffle clean and free of distracting light, and it removes a potential source of electrical noise near sensitive circuitry. Setup and adjustment are handled visually and precisely through the StreamMagic app instead.
Connectivity and System Integration
What physical inputs does the L/R M provide?
The L/R M offers HDMI eARC, optical TOSLINK, RCA line level, a Moving Magnet phono input, USB-C audio, USB-A media, and Bluetooth, with no coaxial digital input. This is an unusually complete input set for a compact active speaker. HDMI eARC allows the system to connect directly to a television and receive high-quality audio while supporting volume control and CEC handshaking, making it a legitimate anchor for a living room setup. Optical TOSLINK handles other digital sources with galvanic isolation, since light carries no electrical ground connection and therefore blocks ground loop noise. The RCA line input accepts any analog source, and the USB-C audio input allows a computer or compatible device to send a clean digital stream directly.
Why does the L/R M include a Moving Magnet phono stage?
The built-in Moving Magnet phono input means you can connect a turntable fitted with a Moving Magnet cartridge directly, without a separate phono preamplifier. Phono signals are extremely low in level and require both significant gain and precise RIAA equalization to restore the correct frequency balance that is deliberately applied when records are cut. Integrating this stage inside the speaker spares the enthusiast from sourcing an external phono preamp and keeps the vinyl signal path short, which minimizes opportunities for noise pickup before amplification.
How do the two speakers connect to each other, and what other outputs exist?
The two speakers link over a wired USB-C inter-speaker connection, and the system also provides a subwoofer output. The wired USB-C link between primary and secondary carries the audio and control data reliably, avoiding the latency and potential dropout risks of a wireless connection between channels, which keeps left and right perfectly synchronized. The subwoofer output lets you add a dedicated low-frequency partner if you want to extend bass below the speaker's own capability or fill a larger room, with the crossover managed by the system's processing.
What streaming and network features does the L/R M support?
The L/R M runs on Cambridge Audio's StreamMagic Gen 4 platform with dual-band Wi-Fi and supports AirPlay 2, Chromecast built-in, Roon Ready, Spotify Connect, Tidal Connect, Qobuz Connect, and Amazon Music, plus Bluetooth. Dual-band Wi-Fi allows the speaker to connect on either the 2.4 GHz or 5 GHz band, with the 5 GHz band typically offering more bandwidth and less congestion for stable high-resolution streaming. Roon Ready certification is significant for serious enthusiasts, as it confirms the device integrates properly into a Roon ecosystem with bit-accurate delivery and multi-zone management. The native Connect implementations for Spotify, Tidal, Qobuz, and Amazon Music mean each service streams directly to the speaker at full quality rather than being re-encoded through a phone.
Build, Finishes, and Lineup Position
How big are the speakers and how are they built?
Each cabinet measures 158 x 263 x 190 mm (6.2 x 10.4 x 7.5 inches), a genuinely compact footprint that suits desktops, bookshelves, and stands. The force-cancelling side radiator arrangement means the enclosure design prioritizes rigidity and low resonance, since any energy the cabinet walls absorb and re-emit would color the sound. The relatively small volume is offset acoustically by the passive radiators and DSP-managed drivers working together, which is how a cabinet this size can reach a 40 Hz lower limit.
What finishes are available?
The L/R M comes in Black, White, Blue, Green, Orange, and Real Walnut, giving a broader palette than most audio components offer. The neutral Black and White options suit traditional installations, the color finishes acknowledge that a compact active speaker often lives in visible living spaces, and the Real Walnut option provides a genuine wood veneer for those who want a warmer, more classic aesthetic.
Where does the L/R M sit in the Cambridge Audio lineup?
The L/R M occupies the all-in-one active streaming speaker category within Cambridge Audio's range, distinct from the brand's separate components such as the Evo all-in-one players, the CX and Edge amplifier and streamer series, and traditional passive loudspeakers. Where the Evo and Edge lines cater to enthusiasts assembling systems from discrete pieces, the L/R M consolidates streaming, DAC, amplification, and speakers into a single matched pair, sharing the StreamMagic platform that underpins the brand's networked products. It is aimed at the listener who wants Cambridge Audio's engineering and streaming ecosystem in the most space-efficient, fewest-boxes form the company offers, without sacrificing the connectivity depth that defines the brand.
Taken as a whole, the L/R M is a coherent expression of Cambridge Audio's active design thinking: efficient Class D power matched precisely to a carefully chosen driver array, force-cancelling passive radiators for clean bass from a small box, DSP-managed crossover and room correction, and a connectivity suite deep enough to anchor a real system. For the experienced listener, it offers the discipline of the brand's separates thinking in a fully integrated, remarkably compact package.