BeoLab 50 Reviews

“So how do they sound? Well, after a lengthy listening session in the Struer listening rooms, I had to conclude that these speakers may look (almost) conventional, but they sound anything but. There’s massive bass, seeming unburstable but as tightly controlled as it is extended, and a lovely sense of integration, sweetness and detail in the midband and treble.”

“If the BeoLab 90 saw the company moving back into the audiophile arena, albeit with a speaker whose form-factor was, to say the least, challenging, then the BeoLab 50 may well win it even more fans in the ‘serious audio’ arena, not least due to industrial design making it look like – well, like a pair of speakers.”

“The BeoLab 50 seemed to cope with hotel-room acoustic issues well, too, possibly because of the side-firing woofers and the active room correction. Bass and high frequencies, in particular, were free from boominess, standing waves, cancellations and weird reflections. At the same time, there was an impressive recreation of instrumental sounds on the Vaughan track, both on the initial notes and on reverb trails that drifted far back into the soundstage”


  1. Preben Sørensen says:

    I understand from the article that a ‘new Cube’ is planned in Struer. This must confirm that B&O – with you, Geoff, in front I suppose – is focusing further on developing leading capabilities within acoustics. Combining design with new high-end technologies with advanced DSP control etc. as in BL 90 and BL50 is really fantastic and a differentiator compared to traditional high-end speaker companies. The sound quality is remarkable. Hopefully this – supported by good reviews in HIFI magazines – forms basis for branding of B&O as being in front as a loudspeaker company.

    I am really looking forward to see the technologies behind BL90/50 used in future smaller speakers. There is definitely room in B&O speaker range for a BL30 or what the name might be.


  2. Hi Preben,

    From the point of view of someone in the acoustics department – I’m certainly no more “in front” than any of my colleagues. I just sit closer to the window, so I’m a little more visible from the outside world… :-)


  3. Preben Sørensen says:

    Hi Geoff,

    Yes, I am sure you are part of a highly skilled and motivated acoustics department. It is really an improvement – compared to old B&O days – that “someone near the window” is visible to explain the world and brand the technology behind – and not only focusing on design. I am enjoyed.


  4. Dear Geoff, I recently discovered your blog. Very enlightening. Thankful that you share your knowledge so genereously!

    I have a question about the development of the Beolab 50s and 90s. Why have you put so much amplifier power in them? Is it needed? Does it improve sound quality or dynamics on moderate volumes as well, or is it mainly to allow them to play very loud if needed? I’m asking from the perspective of someone who still dabbles in speakers without built-in amplification, and I’ve been having an argument with myself as to the merits of using over-powered amplifiers.

  5. Hi Olav,

    I’m not sure that I can answer your question completely, but I’ll try to come close…

    The easiest way to view this issue is to work backwards. We start with a target maximum SPL from our loudspeaker. This is not as simple as it sounds, since this has to take the issue of time into account. This is because the maximum amount of sound pressure that a loudspeaker can deliver is not only dependent on its instantaneous maximum excursion (which may be linked to an acceptable amount of distortion) but other factors such as the product’s ability to pull heat away from the voice coil. However, to keep things simple, let’s assume a one-dimensional case where we want to push and pull the driver to its excursion limit (however that might be defined…).

    We can calculate and/or measure the amount of voltage that is required to move the driver to this desired excursion. So, basically speaking, the amplifier applies the voltage that we want, and the impedance of the driver dictates the current that is demanded from the amp as a result. As long as the amplifier (and power supply) can deliver the necessary current at the voltage we’re applying, then we’re happy.

    In the case of Bang & Olufsen loudspeakers, we have the advantage that we make active loudspeakers – therefore we can define the requirements of the amplifier based on the desired behaviour of a single driver. If you’re designing loudspeakers with passive crossovers, then this is different…

    What this means in the end is that, from a perspective of the electrical design of the loudspeaker, we don’t really care about power directly. We ensure that the amplifier can deliver the voltage swing that we require – and that the resulting current is available. So, for example, in the case of the woofer amp’s for the BeoLab 90, we did not say “we need a 1000 W amp on each driver”. We stated a minimum requirement for the voltage and current, and then used an amplifier that could deliver this.

    There is another way to look at this – which is a small window into our world. Let’s say that you have two amplifiers, amp “A” and and amp “B”. Both are rated at being able to deliver 1000 W. However, Amp “A” can deliver 20 V and 50 Amps (20 V * 50 A = 1000 W). Amp “B” can deliver 50 V and 20 Amps (50 V * 20 A = 1000 W). These two amps will behave very differently at high levels. So, although it’s nice for the marketing materials to state how many watts an amplifier or an active loudspeaker has, this is basically unable information for the people that are doing the loudspeaker design. When we’re developing a loudspeaker, we almost never talk about the power capabilities of our amplifiers. We have to use the Voltage and Current capabilities instead.

    Of course, if you’re designing your system so that your amplifiers are current sources instead of voltage sources, then everything I said above is different – but similar… You’re just looking at the problem from a different perspective. But you still don’t directly worry about the power capabilities of the amp(s).

    In fact, the only really useful power value for our loudspeakers is the one that tells you the average power consumption over time. This lets you know how much it costs per hour (on your electricity bill) to listen to your loudspeakers.

    Hope this is reasonably clear… :-)

    – geoff

  6. Hi Geoff, thank you so much for taking the time to give such a detailed answer! I stand enlightened!

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