The Harman Kardon Radiance 2400 approaches home audio as a complete system rather than a collection of separate components. Its 2.1 configuration combines two tall, ultra-thin satellite speakers with an active subwoofer and a central digital hub. Amplification, digital conversion, source management and wireless streaming are integrated into the package, reducing the need to assemble and accommodate a conventional stack of electronics.
Its most distinctive elements are the 1.8-meter speaker columns. Each is only 5 cm wide and 6 cm deep, dimensions made possible by an array of specially calibrated 1.25-inch full-range drivers. The resulting architecture gives Radiance 2400 an unusually narrow physical profile while supporting Harman’s Constant Beamwidth technology, which is intended to provide more consistent coverage across a room.
An Ultra-Slim Alternative to Conventional Floorstanders
Traditional floorstanding speakers generally rely on comparatively wide and deep enclosures to accommodate multiple drivers and the cabinet volume required for bass reproduction. Radiance 2400 separates those responsibilities. Its slender columns handle the front channels, while a dedicated active subwoofer takes care of low frequencies.
Each satellite stands 1.8 meters tall but measures just 5 cm across and 6 cm deep. That combination is visually significant: the speakers have considerable height, yet their narrow frontage and shallow cabinets can make them less imposing from many viewing angles than conventional box speakers. They remain prominent architectural objects, but their proportions are better suited to interiors where broad speaker cabinets would feel intrusive.
The dimensions are enabled by a vertical row of specially calibrated 1.25-inch full-range drivers inside each column. This is not simply a conventional speaker compressed into a thinner enclosure. The driver arrangement is central to both the appearance of the system and its approach to distributing sound throughout a listening space.
Moving deep bass duties to a separate subwoofer also gives the columns a clear role within the system. Rather than forcing the narrow enclosures to cover the entire frequency range, Harman Kardon pairs them with an active 10-inch subwoofer powered by a 200-watt amplifier. This division allows the system to retain its slim satellite design while still including dedicated low-frequency hardware.
Constant Beamwidth Technology and Wider Room Coverage
Radiance 2400 incorporates Constant Beamwidth technology originally patented by Harman for professional applications. Its purpose is to manage the speaker system’s radiation pattern so that listeners in different positions receive a more consistent presentation. Harman positions this as a way to reduce dependence on a narrowly defined listening sweet spot.
That goal can be particularly relevant in multipurpose living rooms. A conventional stereo arrangement is often optimized around one central seat, even though music may be enjoyed while people are sitting in several places or moving around the room. Radiance 2400 is designed around a broader social use case, where the system should serve more than one fixed listening position.
The technology does not remove the need for thoughtful speaker placement, and room layout will still matter. However, controlled dispersion is an important part of the product’s identity rather than an incidental feature. The tall driver arrays, their calibration and the Constant Beamwidth system are intended to work together as a coordinated solution for room coverage.
Amplification and Conversion Built Into the Speakers
At the base of each satellite are wireless receivers, digital converters and amplification. This integrated architecture means the Radiance 2400 does not require a separate stereo power amplifier connected to the speakers by conventional long cable runs. Audio is distributed wirelessly from the system’s digital hub, while the necessary signal processing and power stages are incorporated into the speaker columns.
The amplifiers use Harman Digital Loop Amplifier technology. According to the documented design rationale, this technology is intended to compensate for disadvantages associated with Class D amplification. Harman Kardon does not merely use Class D power for packaging efficiency; it adds its own amplifier technology as part of the implementation.
Housing conversion, reception and amplification at the speakers also reinforces the system-level nature of the product. The owner is not expected to select separate amplifiers or match their power characteristics to the satellite arrays. Those decisions have already been made as part of a unified design. For someone who wants an advanced audio installation without building a traditional component chain, that integration is one of the Radiance 2400’s practical attractions.
A Digital Hub at the Center of the System
Source selection and signal management are handled by the Harman Kardon Radiance digital hub. It effectively serves as a wireless preamplifier, generating and distributing signals for the speakers while providing connectors for external audio sources.
Centralizing those functions keeps everyday operation separate from the tall speaker columns. Sources connect to the hub, and the hub communicates with the active loudspeaker system. This creates a cleaner division between control and reproduction while avoiding the size and complexity of a conventional preamplifier and power-amplifier combination.
The availability of physical source connections also matters because Radiance 2400 is not restricted to app-based playback. Owners can integrate other audio equipment through the hub, although the exact connection requirements of a proposed system should be checked against the hub’s available inputs. The overall concept accommodates both connected sources and network streaming within one control point.
Chromecast, AirPlay and Multiple Control Options
Built-in Chromecast and AirPlay support allow the digital hub to operate as a self-contained streaming component. Compatible phones, tablets and computers can send audio to the system without an additional network streamer. This makes Radiance 2400 suitable for households already using either of those established casting ecosystems.
The product also avoids relying on a single control method. Its hub has an integrated LCD display for direct interaction, while the supplied remote uses a Bluetooth connection. Smartphone control provides another option for users who prefer app-based operation.
This flexibility is useful in a shared home. A phone may be the most convenient way to choose streamed music, but a physical remote and visible display allow basic operation without making one person’s mobile device the permanent control center. Bluetooth communication for the remote also avoids the line-of-sight requirement associated with traditional infrared handsets.
A Coordinated System Rather Than a Component Platform
Radiance 2400 is best understood as an integrated 2.1 ecosystem. The columns, amplifiers, subwoofer and digital hub have defined roles and are supplied as a coordinated package. That can simplify installation and remove questions about amplifier matching, digital conversion and the selection of a suitable bass solution.
The trade-off is that this is not the same proposition as a modular separates system. Enthusiasts who enjoy changing amplifiers, experimenting with different DACs or selecting every speaker independently may prefer a more conventional route. Radiance 2400 instead emphasizes cohesion, reduced equipment count and a consistent industrial design.
Its CES 2021 Best of Innovation award in the High-Performance Home Audio or Video category also reflects the distinctiveness of that complete-system approach. The notable aspect is not one isolated specification, but the way controlled-dispersion arrays, active amplification, dedicated bass and network playback are brought together.
Who the Harman Kardon Radiance 2400 Is For
The system is most suitable for listeners who want serious home-audio functionality without a visible rack of amplifiers, converters and streaming components. Its very narrow speaker columns could appeal in design-conscious living spaces, especially where wide conventional floorstanders would dominate the room.
It is also relevant to households in which music is enjoyed from several seats rather than one carefully maintained central position. Constant Beamwidth technology is specifically intended to address that situation, making the system conceptually well matched to social listening and open living areas.
Prospective owners should still account for the 1.8-meter height of the satellites. They are exceptionally slim, not physically inconspicuous, and their strong vertical presence will suit some interiors better than others. Buyers should also consider whether the hub’s source connectivity meets their particular equipment needs. For users who prioritize component swapping or a fully modular upgrade path, the system’s tightly integrated structure may be less appropriate.
Conclusion
The Harman Kardon Radiance 2400 stands out through the coherence of its design. Tall arrays of calibrated 1.25-inch drivers create exceptionally narrow speaker columns, Constant Beamwidth technology targets more consistent coverage across multiple listening positions, and a 200-watt active 10-inch subwoofer handles low-frequency duties. Integrated conversion and amplification reduce the need for separate electronics, while the digital hub adds external source connections, Chromecast, AirPlay, an LCD display, Bluetooth remote control and smartphone operation. It is an especially compelling concept for design-conscious listeners seeking a complete, streamlined 2.1 system for shared living spaces rather than a traditional collection of interchangeable hi-fi components.
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