KEF Kube 8b

MJ17.05.2019

Subwoofers

This KEF’s Kube 8b review is not your standard review. We have published many pages about subwoofers and how to set them up correctly. Yet our readers ask the same basic questions again and again – therefore I will share some practical experience from my Kube 8b’s auditioning.

Function and form

80%
Ease of use
45%
Sound
100%
Appearance

The KEF Kube 8b is one of the smallest and most beautiful subwoofers I have reviewed so far. Forget about the internet images, nothing will prepare you for how cute this 30cm cube is. The top black glass plate is surrounded by a fabric from all sides. The rear control panel is embedded into it. There is a 200mm bass driver in the Kube 8b’s cabinet but the driver cannot be seen as the fabric cannot be removed. The subwoofer is powered by a 500W Class D amplifier and provides 105dB of acoustic pressure – enough for small and mid-sized rooms. The control panel provides phase setting (switchable between 0 and 180°), volume control and low pass filter setting (40-180Hz). KEF included also a simple DSP processor that will help you optimize the subwoofer for placement – in room, corner or cabinet. Don’t be afraid to experiment as actually you may find that cabinet voicing is the best for you while the sub is actually not in any cabinet. The good thing is that the Kube 8b can be connected via loudspeaker cable to amplifier or speakers. The power inlet is of IEC C8 type so no use for aftermarket high end cords here. Everything is clean and well thought.

Bass management

Weight
45
Slam
50
Articulation
50

The problem of good bass is not a problem of a subwoofer, rather it is a problem of a room. In my room I hear less bass at 50Hz point which is a result of room modes. The only thing I can do about it is to move my listening chair. This solves the problem but creates another problems at different frequencies. Anyway, I tried to tackle the issue with the KEF.

I placed the Kube 8b into my listening position at the ear’s height and then crawl around the room to find out the spot where the bass drop fills in. When such a spot was found I moved the sub over there and set it up by ears. How to do this is described in detail in our articles.

Clarity & delicacy

Detail
70
Transparency
56

No matter that everything was technically correct the 50Hz fill in did not contributed to what I heard so much I expected. But the low rumble filled in the whole house. I ran with a handheld decibel meter around the house and in some rooms I measured up 110dB of acoustic pressure – which is a good rock concert volume.

What I want to say is that the temptation to fill in narrow band fluctuations with a subwoofer don’t have to be necessarily appreciated by other members of your family or by your neighbours.

Tonal accuracy

Timbre
60
Dynamics
52
Temporal resolution
45

The KEF Kube 8b is a good subwoofer, nothing less nothing more. Up to ca 25m2 it will be a good companion for stand-mounted speakers or for bookshelf monitors. It looks nice which counts a lot as most subwoofers are just big black ugly boxes. When critically auditioned it reliable added the bottom octave to Steinway grand piano even with floorstanding speakers and complemented their ambience. Without it the music breathed less.

Spatial resolution

Holography
70

One final remark. The fabric is quite thick and tight and at certain frequencies it creates a kind of secondary membrane in front of the driver. When I played loud bass heavy music I could hear the fabric resonate. This was audible with sustained signals like synthesizers or organ and did not appear in transient programmes like kick drum or electric bass. It is also possible that only the reviewed piece was doing so.

Price as reviewed:15 000,- Kč

Recommended resellers

Perfect Sound Group, Praha, tel. +420 722 960 690

Associated components

  • Sources: Accuphase DP-720, Accuphase DG-58
  • Amplifiers: TAD-M2500 MkII
  • Interconnects and speaker cables: Audioquest Vodka, Audioquest Redwood, Vovox Sonorus XL, Audioquest Wild
  • Loudspeakers:  TAD Evolution One E1, SVS SB-3000
  • Power conditioning: Shunyata Research Sigma HC, Shunyata Research Denali 6000T, Nordost Valhalla, Synergistic Research Atmosphere Level 2

Gallery

BOWERS & WILKINS DB-1

The DB-1 subwoofer is a simple monolithic cube finished in flawless piano lacquer. It extends ca half a meter to any side and is incredibly heavy. I had to pull the 50 kgs of the sub upstairs and it was not an easy job, rather an ...

Recommended resellers

Eurostar Ostrava, Dobřejovice u Prahy, tel. + 420 323 606 877

Jasyko, Brno, 541 210 108

Sound
96%

KEF Kube 8b

This KEF’s Kube 8b review is not your standard review. We have published many pages about subwoofers and how to set them up correctly. Yet our readers ask the same basic questions again and again – therefore I will share some ...

Recommended resellers

Perfect Sound Group, Praha, tel. +420 722 960 690

Sound
45%

SVS SB-3000

From my previous experience with top-of-range subwoofers from Velodyne, REL and Bowers & Wilkins I was expecting more or less the same procedure. Though the basics are similar the SVS makes the dial-up routine much more visual and ...

Recommended resellers

High-End Audio Studio, Praha, tel. +420 224 256 844

Sound
97%

VELODYNE DD12+

The bass extension of the DD-12+ is specified as -3dB point at 17Hz. With the exception of a cathedral organ there is no other instrument fundamental that requires such the extension for pure stereo playback. Apart from few tracks on ...

Recommended resellers

High-End Audio Studio, Praha, tel. +420 224 256 844

Sound
90%

VELODYNE SPL-800 Ultra

Originally subwoofers were designed to support home cinema installations and as such they had been ignored by an audiophile crowd. The assumption that a pair full-range loudspeakers can deliver precise and extended low frequencies is ...

Recommended resellers

High-End Audio Studio, Praha, tel. +420 224 256 844

Sound
75%

VINCENT Subwoofer Cable

There is not many of specialized subwoofer interconnects on the market as normally only a few customers pay attention to this element -  sellers promote the usual ´for subwoofers a standard quality cables are sufficient´. Not for ...

Recommended resellers

Hifi studio MeLissa, Brno, tel. +420 777 041 313

Sound
75%
Back to category