BeoLab 4000 Active Loudspeakers

BeoLab Loudspeaker

Production: 1997 - 2013

"When it comes to sound reproduction we believe there's only one relevant parameter: How close can we come to the originally recorded sound. We feel an obligation not to disturb the intentions of the artist by adding unnatural elements to the acoustic image. Therefore all Bang & Olufsen loudspeakers share the same goal. They differ in size and shape and in terms of sound pressure level. But they are all developed to reproduce the natural, unaltered sound as closely as possible " - Bang & Olufsen catalogue 2001 - 2002

Squeeze a pair of BeoLab 4000s into the bookcase in your study and link them to the music system in the living room, via a Beolink® 'eye', which responds to your remote control. Whether it's a matter of placement or simple colour co-ordination, BeoLab 4000 turns flexibility into an art form. Placing amplifiers directly in the loudspeakers themselves not only improves sound quality but allows the manufacturer to reduce the cabinet's overall size. The result is a compact loudspeaker that can sit on a shelf, bookcase or hang, at almost any angle, from the wall or ceiling. Available in six vivid colours, BeoLab 4000 is equally at home in a stereo setup, a surround sound system or as superior multimedia speakers for your computer.

 BeoLab 4000 fills the room with sound

You can’t see sound, but that doesn’t mean that it has to be totally invisible. BeoLab 4000 is formed from aluminium that’s polished until it shines like a mirror. It also comes in an array of colours - not only to suit your interior decoration, but because life itself is full of colour


Aluminium is the perfect material for BeoLab 4000. It’s light, but offers an impressive stiffness despite a thickness of only a few millimetres. It also makes it easier to obtain the loudspeaker’s unique curved form, which is important for avoiding problems with audible artefacts due to internal standing waves in the cabinet

Active loudspeaker

 The equation used to be a simple one; the louder the sound, the bigger the loudspeaker - but not anymore. Placing the amplifier directly into the loudspeaker allows us to reduce the overall size of the BeoLab 4000 to one third of a conventional loudspeaker with the same sound capacity.

Adaptive Bass Linearisation

 Adaptive Bass Linearisation (ABL) is a process patented by B&O and is incorporated in BeoLab loudspeakers. The idea is to use the surplus capacity in amplifiers and driver units, arising by normal listening levels, for a bass extension - a sound reproduction with more bass, than the loudspeaker otherwise would be able to produce.

The function is adaptive. This means that the loudspeaker adapts to the signal it receives. Loudspeaker drivers are therefore fully exploited, without suffering mechanical or electronic abuse, and the built in amplifiers are not subjected to signals would otherwise create an overload situation.

ABL gives stunning bass reproduction considering the size of the loudspeaker in which it is incorporated, under normal listening levels.

Why build amplifiers into the loudspeakers instead of keeping them separate?

 Because you can reduce the size of the cabinet volume to one-third of the size of a conventional loudspeaker with the same sound capacity. The principle is called Active Loudspeakers, and what you get is a compact loudspeaker that can play at high volume without distortion or damage to its drive units. Furthermore, when amplifier, treble and bass units are paired for the same task, they can be tailored to compensate for each other's shortcomings. What you hear is music that sounds exactly like the instrument it originally came from.

The cube

 During the development phase, all BeoLab loudspeakers are put through their paces in ‘The Cube’, Bang & Olufsen’s own acoustic measurement facility. In the 12 x 12 x 13 metre room, the entire audible spectrum is played through the loudspeaker to give a perfect picture of it’s sound ‘fingerprint’.


To ensure an optimal performance every time you listen to it, a BeoLab loudspeaker constantly fine-tunes the signal received from the sound source before distributing it out to the separate bass and treble power amplifiers.

The listening panel

Since it’s humans that will listen to BeoLab 4000, it’s important that a human ear should also measure its quality. That’s why Bang & Olufsen employs its own Listening Panel to scrutinise every step in a loudspeaker’s development. If any sonic shortcomings are discovered, the whole project is returned to the drawing board.

Individual Calibration

Since no two loudspeaker units have exactly the same physical characteristics, we calibrate them individually to make certain that the sound of each and every BeoLab 4000 loudspeaker leaving the factory is identical.


 Using aluminium for the cabinets is not just about looking good. Despite a thickness of only a few millimetres, it’s a remarkably strong metal that's easily shaped to eliminate the problems with audible artefacts due to internal standing waves in the cabinet.

Rule of thumb

Substitute cabinet volume (the amount of space a loudspeaker takes up) for amplifier power (which doesn’t take up much) and cabinets like that of the BeoLab 4000 can be reduced to one-third the size of a conventional, passive loudspeaker with the same sound capacity.

Flexibility in placement

You can use BeoLab 4000 as your main loudspeakers or as extras in a Bang & Olufsen surround-sound set-up. Their ability to fit into the smallest of spaces, or to be hung on the wall at almost any angle, also makes them the perfect loudspeaker for the Beolink® system. BeoLab 4000 owes its shape to the fact that active loudspeakers produce heat if they have to play for a long time without a pause. Squeeze it into a bookcase and it will still have sufficient cooling air around it, no matter how many books it shares its space with. Raised on the optional stand, BeoLab 4000 presents itself at the same angle as BeoSound Ouverture.

Even Cooler?

2007 saw the introduction of the Beolab 4000 Mk2 . Almost unheralded, the main change was the use of ICE amplifiers to replace the AB type. At first glance it would appear that the amplifiers from the Beolab 4 were being used. These offered a power output of 35W each with 2 being used. This was remarkably similar to the real output of the older amplifiers and not surprisingly the maximum sound levels achievable were not changed. Indeed it was unlikely that any customers would have noticed the change if not told.

Part numbers: BeoLab 4000 front covers

Green 1603894

Grey 1603895

Black 1603896

Yellow 1603897

Blue 1603898

Red 1603899

Mounting Options

Wall mounting brackets were supplied with this model. Pole mounted Floor Stands were the only other option.

BeoLab 4000 Active Loudspeakers technical specifications

Market, type & introduction year: 

EU 6636 1997 
GB 6637 1997 
USA 6638 1997 
J 6639 1997 
AUS 6640 1997 
KOR 6641 1998 
CHK 6649 2004-06 

Specifications: (from Aug 2005): 
Dimensions W x H x D/Weight: 28 x 32 x 13 cm / 6 kg 
Cabinet/cloth finish Silver/silver, black/ black, blue/black, dark grey/dark grey, red/black, yellow/yellow 
Stopped June 2005: green/green, red/red, blue/blue 
Power consumption Typical 10 watts/stand-by 0,5 watts 
Mains 6636 EU 230V 
6637 GB 230V 
6638 USA-CDN-TWN 120V 
6639 J 100V 
6640 AUS 240V 
6641 KOR 120V 
Maximum Sound Pressure Level (stereo, pair) 97 dB 
Power amplifier modules 2 units, Class AB 
Long-term maximum output power per module* 59 watts 
Effective frequency range* 55 - 20,000 Hz 
Cabinet principle Bass Reflex 
Magnetic shielded Yes 
Woofer 11 cm 
Tweeter 1.8 cm 
Net volume 4 litres 
Bass equalizer Adaptive (ABL) 

According to IEC 268-3 and 268-5 

Connections: Power Link 2 
Phono (line) 1 

Link compatibility: 
Link compatibility: BeoLink Active 
BeoLink PC Office 


Accessories Floor speaker stand 2069 Aluminium 
Stand 2064 Black 
Base 2037 Black 
Front cover 6038 Black, Blue, Green, Grey, Red, Yellow

More Bang & Olufsen Items

The brand names Bang & Olufsen, B&O, trade mark and many of the product names and details together with on-site photographs are the property and copyright of Bang & Olufsen. The information on this website is provided only as a guide to Bang & Olufsen collectors and enthusiasts of the marque.

Jaguar History: The Century of Automotive Excellence