• KEF SP3939BA Kube8b 300W Active Subwoofer

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    LG 3.1 Ch Soundbar with Wireless Subwoofer SN6Y
    3.2 from 266 reviews
    • Overview
    • Specifications & manuals
    • Legendary service
    • Delivery, services & returns
    • Questions & answers

    Overview

    Feel, as well as hear, the earth-shuddering bass created by the KEF Kube8b Subwoofer, adding potent low tones to your audio that elevates it to new heights. With an unassuming design it would be easy for the Kube8b to escape your notice, and therein lies its strength. A minimalist and elegant finish allows it to unobtrusively blend into your entertainment setup, that is, until it’s turned on.

    Utilising an eight inch driver, the Kube8b is optimal for filling smaller rooms with rich, transparent sound. For that extra bit of boom, the Intelligent Bass Extension (iBX) extends the bass depth, unlocking the true potential of the driver’s power. With KEF’s smartConnect, the input automatically detects whether it is connected to a mono or stereo system and adjusts the volume accordingly.

    Your Kube8b Sub can comfortably suit any room placement thanks to a large range of configuration options. Low-frequency effects, line and speaker-level inputs, three DSP controlled EQ settings and Phase selection puts control of your audio into your hands. And with a built-in Class D amplifier, you never have to worry about whether your Kube can excel at higher volumes.
    ibX- Intelligent Bass Extension

    If you don't have deep, rich, rumbling bass, do you really have bass? The ibX algorithm creates extended depth that unleashes the full potential of the driver, delivering detailed lower tones.

    Sealed Cabinet

    The sealed cabinet maintains the highest accuracy and detail of your audio, even at louder volumes. With tighter control over your low tones, each beat will sound punchy and dynamic.

    Manual Crossover Adjustment

    An easy-use dial allows you to adjust the Hertz range that this subwoofer can operate at. In essence, this allows a wider range of speakers to work with this unit.

    Compact Design

    Deceptively small, the compact construction of this unit hides its raw auditory power.

    Specifications & manuals

    key Specifications
    Brand
    KEF
    Finish Colour
    Black
    Height (mm)
    293 mm
    Width (mm)
    293 mm
    Depth (mm)
    310 mm
    Model Number
    Kube8b
    Weight (kg)
    11.3 kg
    Accessories included
    Power Cable, User Manual
    warranty
    Manufacturer Warranty
    2 Years
    Warranty Note
    5 Years Warranty on Driver. All other components have 2 Years Warranty
    Use
    Not intended or designed for commercial use.
    audio
    Speaker Channels
    1
    Frequency Response Range
    34 - 140
    Maximum Output
    105 dB
    Subwoofer Power
    300
    Subwoofer Size
    8
    additional Dimensions
    Package Dimensions (H x W x D)
    420 x 395 x 390
    Package Weight (kg)
    11.34

    Legendary service

    The Appliances Online Net Promoter Score (NPS) is based on feedback from 89,897 people, collected between August 2024 to August 2025. Learn more about the Net Promoter Score (NPS).
    Such outstanding service
    Jane, Blackburn, VIC
    No fuss excellent service
    John, Beaumaris
    You made it easy to buy, and ensured that my delivery schedule was on time
    Wendy,

    Delivery, services & returns

    Appliances Online is all about legendary service. We offer free next business day delivery, free connection, free removal and free recycling, and we even offer Saturday delivery and, in some locations, a Premium Delivery option that allows you to choose your own 2-hour delivery window.

    Questions & answers

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