KEF Kube Powered Subwoofer User Manual

Introduction

Thank you for purchasing this KEF Kube powered subwoofer. We are confident that your Kube will provide reliable, high performance sound for many years to come. Please read this manual fully before you attempt any connection to the Kube.

Inside the box

Contents vary by region.

Contents of the box typically include the KEF Kube subwoofer, power cable, and user manual. Specific accessories may vary by region.

Controls and sockets

The KEF Kube subwoofer features several controls and connection points on its rear panel:

P EXP: Expansion port.
12V: 12V trigger input.
MODE: Power mode selector (Auto Wake Up, Always On, 12V).
PHASE: Phase control (0° or 180°).
EQ: Equalization setting.
CROSSOVER: Crossover frequency control, adjustable from 40Hz to 140Hz.
VOLUME: Volume control for adjusting output level.
ON/OFF switch: Main power switch.
AC power input: Connection for the power cable.
High level (speaker) input: Speaker-level inputs for connection to an amplifier.
LFE/Line-in RCA inputs with smartConnect: RCA inputs for LFE or line-level signals, featuring smartConnect technology for automatic gain adjustment.

Positioning

As KEF Kube subwoofers are front-firing, they may be placed near walls, in corners, or even built into walls and cabinets. Please note that while a subwoofer can be placed almost anywhere in a room, it is very important to experiment with different positions to achieve optimal sound. If intending to use subwoofers in rooms with multiple listening positions, KEF highly recommends the use of multiple subwoofers to create a more consistent balance of bass throughout the room.

Diagrams illustrating various subwoofer placement options in a room, including near walls, in corners, and integrated into furniture. These diagrams show how the subwoofer's position can affect bass response, with recommendations for experimentation.

Connections

The KEF Kube subwoofer can be connected in several ways:

Connection to LINE INPUT from a preamp or receiver

SmartConnect: This feature automatically detects if one or two RCA cables are used and adjusts the gain accordingly for optimal subwoofer output. A Y-adapter is not required, and it does not matter if a single RCA cable is plugged into the left or right RCA input.

Diagram showing the connection of a KEF Kube subwoofer to the LINE INPUT of a Surround Preamp/Receiver or a Stereo Preamp/Receiver using RCA cables. The diagram illustrates the use of the LFE/LINE INPUT connectors and the smartConnect feature.

Stereo connection to 2 subwoofers (line input)

This setup involves connecting two KEF Kube subwoofers to a stereo preamp/receiver using line input connections.

Diagram illustrating the stereo connection of two KEF Kube subwoofers to a stereo preamp/receiver via line input using RCA cables. Each subwoofer is connected to the LFE/LINE INPUT ports.

Connection to LINE INPUT from KEF W2 platform speaker

When using with KEF W2 platform speakers, set the subwoofer's MODE to LFE and use the KEF app to set the high and low pass frequencies.

Diagram showing the connection of a KEF Kube subwoofer to a KEF W2 platform speaker via LINE INPUT. The diagram highlights setting the MODE to LFE on the subwoofer.

Connection to SPEAKER INPUT from a stereo amp or receiver

This connection method uses the speaker-level outputs from a stereo amplifier or receiver to connect to the KEF Kube subwoofer's SPEAKER INPUT terminals.

Diagram illustrating the connection of a KEF Kube subwoofer to a Stereo Amp/Receiver using speaker level outputs. The diagram shows the speaker wire connections to the SPEAKER INPUT terminals.

Stereo connection to 2 subwoofers (speaker level)

This setup connects two KEF Kube subwoofers to a stereo amplifier or receiver using speaker level inputs.

Diagram showing the stereo connection of two KEF Kube subwoofers to a stereo amplifier/receiver via speaker level inputs. Speaker wires connect from the amplifier/receiver to the SPEAKER INPUT terminals of each subwoofer.

Connection to KW1 Wireless Subwoofer Adapter Kit (Optional accessory)

For connection with the KW1 Wireless Subwoofer Adapter Kit, please refer to the detailed setup in the KW1 user manual.

Illustration of the KEF KW1 Wireless Subwoofer Adapter Kit, showing its connection port and controls. The text directs users to the KW1 user manual for detailed setup instructions.

Connection to 12V input from a preamp or receiver

This connection utilizes the 12V trigger output from a compatible preamp or receiver to automatically turn the KEF Kube subwoofer on and off.

Diagram illustrating the connection of a KEF Kube subwoofer to a Surround Preamp/Receiver's 12V TRIGGER OUT terminal using a 12V trigger cable. This enables automatic power on/off synchronization.

Manual Controls

Crossover Frequency Control

The crossover frequency control adjusts the upper cut-off frequency of the subwoofer, ranging from 40Hz to 140Hz at a rate of 24dB per octave. It should be adjusted for smooth integration between main/satellite speakers and the subwoofer. Clockwise rotation increases the frequency, while anti-clockwise rotation decreases it.

Diagrams illustrating the effect of the crossover frequency setting:

Ideal crossover: Flat response.
Crossover point too low: Causes a dip in the combined response.
Crossover point too high: Causes a hump in the combined response.

LFE mode is recommended for home theatre LFE (.1) channels or when bass management is handled by the AV receiver, preamplifier, or active speaker system.

Volume Control

The volume control adjusts the subwoofer's output level relative to the satellite or AV speaker output level. Clockwise rotation increases the level, and anti-clockwise rotation decreases it. It is recommended to start near the middle setting and adjust for the best balance.

Diagram of the VOLUME control knob, showing MIN and MAX settings.

Phase Control

The phase control is typically set to 0°. However, setting it to 180° may sometimes yield higher output levels, particularly when the subwoofer is placed far from the satellite speakers.

Diagram showing the PHASE control with 0° and 180° positions.

Mode Control

There are three power modes:

Auto Wake Up: The subwoofer powers on automatically when an audio signal is detected. It turns off after 20 minutes of inactivity to save power. With KEF W2 platform speakers, the 'Force sub wake-up' feature in the KEF Connect app can synchronize power on/off.
Always On: The subwoofer remains powered on continuously and does not enter standby mode. Use the main power switch to turn it off.
12V: Used when the 12V trigger input is connected to a compatible amplifier or receiver's 12V trigger output, allowing automatic power synchronization.

Diagram of the MODE selector switch with 'Auto wake up', 'Always On', and '12V' options.

Specifications

The KEF Kube series offers several models with varying specifications:

Model	Kube 8 MIE	Kube 10 MIE	Kube 12 MIE	Kube 15 MIE
Design	Powered Subwoofer (Sealed)	Powered Subwoofer (Sealed)	Powered Subwoofer (Sealed)	Powered Subwoofer (Sealed)
Drive units	1 x 200mm (8in.)	1 x 250mm (10in.)	1 x 300mm (12in.)	1 x 380mm (15in.)
Frequency response	34Hz - 140Hz (-6dB)	24Hz - 140Hz (±3dB)	22Hz - 140Hz (±3dB)	20Hz - 140Hz (±3dB)
Max output	105dB	111dB	114dB	116dB
Amplifier type	Class-D	Class-D	Class-D	Class-D
Amplifier power	300W RMS	300W RMS	300W RMS	300W RMS
Variable Low Pass Filter	40Hz - 140Hz, LFE	40Hz - 140Hz, LFE	40Hz - 140Hz, LFE	40Hz - 140Hz, LFE
Input	RCA phono sockets Speaker level inputs Expansion port for KW1	RCA phono sockets Speaker level inputs Expansion port for KW1	RCA phono sockets Speaker level inputs Expansion port for KW1	RCA phono sockets Speaker level inputs Expansion port for KW1
Power requirements	100-240 V ~ 50/60 Hz	100-240 V ~ 50/60 Hz	100-240 V ~ 50/60 Hz	100-240 V ~ 50/60 Hz
Power consumption	300VA	300VA	300VA	300VA
Dimension (H x W x D) with Rear panels and Feet	293 x 293 x 310 mm 11.5 x 11.5 x 12.2 in.	370 x 353 x 370 mm 14.6 x 13.9 x 14.6 in.	410 x 393 x 410 mm 16.1 x 15.5 x 16.1 in.	519 x 500 x 515 mm 20.4 x 19.7 x 20.3 in.
Weight	9.4 kg	15.4 kg	18.6 kg	27.5 kg

Visit: KEF.com for more about KEF and its products. KEF reserves the right, in line with continuing research and development, to amend or change specifications. E&OE.

Manufacturer Information

GP Acoustics (UK) Limited
Eccleston Road,
Tovil, Maidstone
Kent, ME15 6QP
UK

CE marking and WEEE symbol (crossed-out wheeled bin) indicate compliance with European standards and disposal guidelines.

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