Mis à jour le 5 October 2021.
Barely larger than a football, the KEF KC 62 subwoofer is a true technology powerhouse. The KEF KC62 features a dual force-cancelling driver powered by digital amplification capable of delivering up to 1000 watts RMS. This exceptional mini subwoofer promises ultra-powerful bass capable of reaching a frequency of 11Hz. Can it compete with a larger model with the same price?
KEF KC 62: packaging & accessories
The KEF KC 62 subwoofer comes in a 30cm cardboard box. Inside this box, the subwoofer is placed in a synthetic cloth and inserted between two thick pieces of polystyrene to ensure it is properly supported and protected during transport. It comes with a quick start guide, an adapter for the speaker-level input and two power cables: one in UK standard and the other in European standard. This cable is relatively long, making it easy to position the subwoofer.
KEF KC 62: presentation
This isn’t the first time that the British brand has created a subwoofer and it has a good reputation in this field, notably thanks to the models in the KEF Kube range: the KEF Kube 8, KEF Kube 10 and KEF Kube 12. More recently, the manufacturer released the KEF KC 62 with the intention of dispelling the myth that it is only possible to achieve deep, powerful bass with bulky subwoofers equipped with huge drivers. The KEF KC 62 subwoofer redefines the rules by promising a performance at odds with its size. Indeed, its dimensions have been reduced as much as possible, with a length of only 256mm, a height of 246mm and a depth of 248mm. That’s significantly smaller than most bookshelf speakers. Yet the KEF KC 62 is capable of going much lower than any pair of speakers, even floorstanders, and promises a similar response to the iconic KEF KF 92, whose enclosure is 63% bigger.
With such a small size, the KEF KC 62 subwoofer is discreet and can be easily hidden in the room. This makes it a great choice for seamless integration into a living room or small living space. For example, it can be placed behind a piece of furniture or under a small table. Its very elegant design also allows it to be left in view, thanks to its particularly appealing matte finish. Its shape and rounded edges are a perfect match for the silhouettes of the KEF LS50 Meta and KEF LS50 Wireless II speakers, with which it can work in total harmony.
To achieve the feat of delivering powerful bass in an enclosure barely larger than a football, the KEF KC 62 features a number of proprietary technologies, including a dual Uni-Core driver developed specifically for this model. The latter uses force cancelling, but instead of placing two separate drivers back to back, the KEF KC 62’s dual driver uses a single large magnetic system. Despite its compact size, the KEF KC 62 weighs over 14kg! This system is combined with overlapping and concentrically positioned voice coils. This provides a number of benefits, including limiting interference and greatly increasing the excursion of each driver. A real feat that ensures deeper and more powerful bass than an active/passive driver configuration, without having to increase the size of the cabinet.
The edges of each cone also benefit from innovations, with a newly designed surround using P-Flex technology. This technology uses pleated edges inspired by the Japanese art of origami to maximize internal sound pressure resistance without excessively increasing the cone’s mass. Each driver is therefore able to move more precisely than those with a conventional design. The result is deeper bass extension and a more accurate and detailed bass reproduction. With its increased rigidity, this surround also allows for a higher listening volume.
To efficiently power the massive magnetic system of the Uni-Core dual driver, the KEF KC 62 subwoofer is equipped with two 500-watt amplification modules that provide a total output power of 1000 watts RMS. Although this output is colossal, the volume delivered by the KEF KC 62 is limited by its size. If you enjoy loud music or have a very large listening room, the KEF KC 62 may be pushed to its limits. However, even when used at its maximum level, the bass remains well controlled thanks to the Class D modules specifically optimized to provide the best possible cone control.
Through the use of digital amplification, the British manufacturer is able to further optimize the performance of the KEF KC 62 subwoofer through a customized selection of algorithms and DSP modes developed in-house. Algorithms such as iBX (Intelligent Bass Extension) and SmartLimiter continuously analyze the audio signal to prevent clipping, optimize the operation of each component, and ensure that the bass is well controlled in all circumstances. This system works in tandem with intelligent distortion control technology that corrects any anomalies. It does this by measuring the current in the voice coil and then correcting any non-linear distortion. This reduces total harmonic distortion by more than 75%, resulting in a more natural, uncolored low frequency range.
The KEF KC 62’s connectivity options allow it to be used with almost any hi-fi or home theater system. Its rear panel features a wide range of connectors, including an RCA stereo input that can be switched to an LFE or line input. A speaker-level input is also available to connect the subwoofer directly to the speaker outputs of an amplifier, via the included adapter. It is also possible to use a wireless connection via the KEF SmartConnect transmitter (not included). Lastly, an RCA stereo output allows you to retrieve the signal and pair the KEF KC 62 to a second subwoofer, if needed.
Because the KEF KC 62 has the ability to fit perfectly into any environment or listening room, it must be able to provide equivalent performance in all situations. To do this, five equalization modes are available, allowing you to optimize the infra-bass according to the location of the subwoofer, whether it is placed in an open space, next to a wall or in a corner of a room, or to hide it in a piece of furniture or use it in an apartment, for example. In addition, the KEF KC 62 has a phase selector (0 or 180°) and two potentiometers: one to adjust the volume and a second to set the crossover frequency from 40Hz to 140Hz according to your speakers, your room or your preferences.
When the KEF KC 62 is paired with a pair of KEF LS50 Wireless 2 speakers, some of the settings can be made directly from the KEF Connect smartphone and tablet app. From here, you can adjust the bass level and crossover frequency, and you can also save your own equalization settings and decide at which frequency the speakers should cut off and leave the sound reproduction to the subwoofer. If you specify that the model is the KEF KC 62, the app automatically selects the recommended settings. It is also possible to add a second subwoofer (one for each speaker) to make them work in stereo.
KEF KC 62: key specifications
- Sealed enclosure subwoofer
- Dual 6.5” force-cancelling driver
- Uni-Core and Surround P-Flex technologies
- 5 equalization modes depending on the placement of the subwoofer in the room
- Total output power: 1000 watts
- Frequency response: 11Hz to 200Hz
- Sound pressure level: 105dB
- Crossover frequency: 40Hz to 140Hz
- RCA and speaker-level input
- Dimensions (WxHxD): 256 x 246 x 248mm
KEF KC 62: configuration
Once the subwoofer is connected to the source and to the mains, all you have to do is select the most suitable placement mode for your configuration, adjust the crossover frequency according to your speakers, then set the volume to your liking. To do this, the KEF KC 62 does not have a calibration system like Velodyne offers with the impressive Velodyne Digital Drive Plus 10, Velodyne Digital Drive Plus 12, Velodyne Digital Drive Plus 15 and Velodyne Digital Drive Plus 18. The adjustments must therefore be made by ear, but it is quite easy and accessible without any technical knowledge. The objective is to achieve optimal bass reproduction, without saturation or distortion that would allow the subwoofer to be pinpointed by ear. It should sound like it is coming from the center of the soundstage, not from its actual location. When setting the crossover frequency, the signals reproduced by the subwoofer and the speakers should complement each other harmoniously, without overlapping or leaving gaps.
For our review, we first connected the KEF KC 62 subwoofer to the speaker outputs of the NAD C375 BEE hi-fi amplifier to support a pair of KEFLS50 Meta speakers. The crossover frequency was set to approximately 80Hz. After that, we tested the KEF KC 62 in a 5.1.2 home theater installation featuring Cabasse Eole speakers and a Marantz AV receiver. The KEF KC 62 was connected directly to the amp’s subwoofer output. Lastly, we paired the sub to the KEF LS50 Wireless 2 speakers to benefit from the settings offered by the mobile app.
KEF KC 62: listening impressions
2.1 – KEF LS50 META (hi-fi)
The KEF LS50 Meta speakers have received much praise from the specialist press for their dynamic character and high transparency. However, many said that only one thing was missing: deeper and more powerful bass. The KEF KC 62 subwoofer was developed in part to address this issue. As such, it allowed the KEF LS50 Meta speakers to deliver a much more balanced sound, with more substance and depth in the lows. We benefited from a real, physical presence, with tense, dynamic and lively bass. The attacks were clean and we didn’t notice any lag, even at high volume.
By pairing the KEF LS50 Metas with this small subwoofer, the lows gained texture and the other frequency ranges seemed clearer and more precise. On the track Looking for the Summer by Chris Rea, the electric bass gained more presence and depth. The notes were perfectly sustained down into the infra-bass, and the soundstage was much more realistic.
2.1 – KEF LS50 Wireless 2 (hi-fi)
The KEF KC 62 subwoofer is the ideal partner for the KEF LS50 Wireless 2s, and can automatically adjust their settings through the mobile app. When paired, it added weight and depth in the lower octaves. It offered the same improvements as those we enjoyed with the KEF LS50 Meta, namely an improved sonic image, with a wider and more spacious soundstage. The percussion instruments, electric bass and other instruments in the low frequency range were more grounded and benefited from a more pronounced and truly captivating rhythm. With bass-heavy tracks such as Daft Punk’s Around the World, the listening experience was more convincing, with a more realistic presence and dynamics that seemed even more powerful.
5.1.2 – Cabasse Eole (home theater)
With its compact size, the KEF KC 62 subwoofer complements the Cabasse Eole satellite speakers perfectly. With Christopher Nolan’s movie Tenet, the KEF KC 62 added texture and reinforced the authenticity of each sequence. Voices gained substance, texture and seemed enhanced. The dynamic character of the small KEF KC 62 revealed its true value during action scenes. Detonations were crisp and impactful, while explosions were intense and had a lot of substance. It’s amazing how this little subwoofer was able to deliver hearty lows and make the floor and sofa in our 25m2 room vibrate when the soundtrack called for it. In a much larger room, however, the KEF KC 62 may reach its limits in terms of power and sound pressure, with the risk of becoming less impactful unless two subwoofers are used.
The benefits of the KEF KC 62 subwoofer in home theater were demonstrated with every movie we watched. With Luc Besson’s Valerian and the City of a Thousand Planets in Dolby Atmos 5.1.2, the sound of the ships crashing onto the indigenous planet became more believable. We could feel the impact of these steel monsters penetrating the atmosphere. The result was much more realistic and the bass spatialization was excellent, and it really sounded as if the effects were coming from the ceiling. The KEF KC 62 subwoofer also reinforced the soundtrack, which was rendered with more conviction and depth.
KEF KC 62 compared to the B&W PV1D
Available for €1,599, the B&W PV1D subwoofer is one of the rare models able to compete with the KEF KC 62 in terms of compactness. The B&W sub 289 x 333.5 x 347mm, which is only slightly larger than the KEF KC 62, which measures 256 x 246 x 248mm. The slightly larger format and the use of two 7.8” drivers allow this B&W subwoofer to go even deeper in the bass, down to 7.5Hz (+/- 3 dB). It is therefore capable of delivering even deeper and more physical lows. As such, it’s a bit better suited for larger rooms, although its 400-watt amplification power is more modest.
KEF KC 62 compared to the Velodyne MicroVee X
Subwoofer specialist Velodyne has recently returned with even more powerful models, including the Velodyne MicroVee X, the smallest model ever designed by the brand. The latter only measures 229 x 229 x 244mm, making it even smaller than the KEF KC 62. In this minimalist format, Velodyne has optimized every parameter with a 6.5” active driver coupled to a 1000W RMS power supply and two passive radiators of the same diameter. Despite this extravagance, the Velodyne MicroVee X cannot go below 18Hz, compared to 11Hz for the KEF KC 62.
KEF KC 62: who is it for?
The KEF KC 62 subwoofer is primarily designed for those who already own a pair of KEF LS50 Meta, KEF LSX or KEF LS50 Wireless 2 speakers and wish to improve the performance of their system. In this respect, the KEF KC 62 provides a much better sound image, with a more spacious and better balanced soundstage. It offers a more depth and texture, and makes the listening experience more coherent and lively. The KEF KC 62 also works well with other hi-fi and home theater speakers, making it a good choice for deeper, more realistic bass, while maintaining a compact system that can be easily integrated and hidden in the room.
KEF KC 62: conclusion
The KEF KC 62 subwoofer arrived on the market with the goal of proving that it is possible to achieve powerful and deep bass without a huge subwoofer. Overall, this objective was met and the KEF KC 62 manages to deliver deep, realistic and dynamic bass. It really works wonders by producing intense, responsive and physical lows in a room of less than 35/40m2. In a larger room, the use of two KC62s or one larger subwoofer is still essential, even if it is at the expense of seamless integration. The KEF KC 62 is the master in this field, with its compact size and various placement options that allow it to be hidden in the smallest corners of the room. Therefore, if your hi-fi or home theater system lacks impact or depth in the lows and your listening room is modest in size, this small subwoofer is one of the most effective solutions to achieve a balanced sound and enjoy a richer reproduction, without compromising the interior decoration.
- The compact and minimalist format
- The impactful and dynamic lows
- The ease of placement
- The simple and refined design
We would have liked
- More powerful bass for large rooms