KEF Kube 15 MIE Subwoofer

The KEF Kube 15 MIE Subwoofer is the flagship of the KEF subwoofer range. It uses a massive 15” bass driver to deliver punchy bass for movies and music in larger rooms and home cinemas. The front-firing driver goes down as slow as 20Hz for bass you can feel.

A 300-watt Class D Amplifier is used along with the KEF-developed iBX Intelligent Bass Extension algorithm. The result is a sound with good depth, control, and dynamics. Various room EQ settings are available and there is a versatile on/off control system. Lastly, a wireless conversion kit can be used to remove the need for connecting wires.

300 watt Class D amplifier

Powerful amplifiers can cause problems in an enclosed space such as a subwoofer cabinet. As a result, a Class D amplifier is used with the KEF Kube 15 MIE Subwoofer. Class D is up to 90% efficient and generates less heat than Conventional Class A/B amplifiers.

Class D also uses less power for a given output. The output consists of a series of high-frequency pulses. This is known as Pulse Code Modulation. At the output fast switching, MOSFET transistors are used along with a low pass filter. The signal remains digital right up to the speaker.

KEF music integrity engine

Most subwoofers such as the KEF Kube 15 MIE Subwoofer have a digital control system that deals with shaping the sound. This is known as DSP or Digital Signal Processing. KEF developed a Music Integrity Engine algorithm as part of the DSP.

This ensures that the sound is well-timed and controlled so that the bass does not overwhelm the rest of the music or soundtrack. Moreover, the sealed enclosure enables the unit to be used in a cabinet. Lastly, different room EQ settings are available.

Versatile power modes

The KEF Kube 15 MIE Subwoofer can be switched on and off in various ways. Firstly, auto-on mode will detect an input and turn the unit on. It will also turn off after a time of inactivity. Secondly, there is a 12V trigger input.

This can be used by a trigger-equipped amplifier to turn the unit on when the amplifier is turned on. Lastly, you can leave the unit powered all the time. A wireless conversion kit is available so that the subwoofer can be used without trailing leads.

Connecting a subwoofer

There are several ways of connecting the KEF Kube 15 MIE Subwoofer to an amplifier or AV receiver. Most AV receivers will have one or more subwoofer line-level outputs. You can also use a stereo preamp output.

On the other hand, older amplifiers will not have a subwoofer output. However, some have two sets of speaker outputs. One of these can be used to feed the speaker-level inputs of the KEF Kube 15 MIE Subwoofer.

Adjusting the unit

There are three main settings with the KEF Kube 15 MIE Subwoofer. The first thing to check is the phase switch. This needs to be set so that the subwoofer phase matches that of the main speakers. Otherwise, the bass may be reduced.

Secondly, the crossover frequency should be set so that the main speakers integrate with the subwoofer correctly. These can both be set by ear. Lastly, the room EQ setting is set to match the size of the room.

Key Features

- Music Integrity Engine® (MIE) – KEF proprietary DSP to further optimise performance
- 300W RMS Class D amplification
- Three room placement settings: Wall/in-cabinet In-room and Corner
- Multiple power modes: Always on, Auto wake up, 12V
- KEF SmartConnect intelligent inputs to automatically detect mono or stereo and adjust the subwoofer volume level accordingly
- Versatile controls for easy integration with any loudspeaker and any home environment
- Sealed for greater accuracy while allowing the Kube to be installed in a cabinet
- Available in four sizes for flexible configuration: Kube 15 MIE, Kube 12 MIE, Kube 10 MIE, Kube 8 MIE
- Optional KW1 wireless subwoofer adapter kit compatible for wireless operation