Beolab 5 - Four Questionable Technologies

Macrojack,
Thanks for the links you provided. In general, the consensus of what you sent seems remarkably positive. It makes me wonder why Audiophiles don’t pay more attention to these speakers. If these speakers are as good as these reviewers/listners say, it would seem that they would be wildly popular with those interested in High End.

Here are some quotes from the links you sent me:
David Ranada from Sound and Vision:

It can play very loud, very clean, it has a very smooth tonal quality free of major colorations and resonances…B&O’s BeoLab 5 is the best speaker I’ve heard in some time, and it embodies extremely important technical innovations that deserve further exploitation.

HomeTheaterForum.com

To find that the only audio publication I have ever respected has given a B&O product such a glowing review - heck, more than a glowing review - floors me.
[He is referring to The Audio Critic which he quotes:] … “the overall sound was superb, as transparent, defined, and alive as I have ever heard out of any speaker”

From your link I went to Peter Aczel’s review in The Audio Critic.
Here is the link:http://theaudiocritic.com/blog/index.php?op=ViewArticle&articleId=6&blogId=1
Quotes from that review:

“the speaker that makes my dream come true in every detail, bar none. I can hardly believe it. Amazing. Speakers will never be the same again.

Bang & Olufsen really did it this time. The Danish firm whose philosophy always seemed to be cosmetics (“Dansk design”) first, engineering second, has leapfrogged the whole speaker industry with an engineering design so advanced and so imaginative that it leaves everyone else in the dust

The most obvious difference between the measured response of the BeoLab 5 and that of any other speaker is the complete absence of high-frequency rolloff at any angle off axis horizontally

The Adaptive Bass Control alone, once activated, produced obviously superior results. The low-frequency response was utterly smooth, effortless, powerful, without the slightest lumpiness, and extending all the way down to dc—or so it seemed. Unbelievable bass. The wide horizontal dispersion of the frequencies above 500 Hz also resulted in a unique listening experience—you can sit anywhere in the room with these speakers, as long as they are somewhere in front of you. The aiming of the midrange and tweeter has become totally uncritical. That alone is worth the price of admission.

It is interesting that speakers this good and this innovative have never been reviewed in the two dominant Audiophile magazines in the USA: Stereophile and The Absolute Sound. Could that fact that B&O never advertises in those magazines have anything to do with that?

One might draw that conclusion.
It is important to recognize that audiophile buyers are sheep who are insecure and driven by consensus opinion.

A dealer I know provided me with this definition of the audio hobby. "Audiophilia is predicated on dissatisfaction and populated by people who listen with their eyes rather than their ears".

In order for a manufacturer to succeed in this business, he must do much more than merely build a better mousetrap.

Back in the 80s I worked for a company called Listen Up who was a B&O dealer and, as such, required all of us sales people to attend Bang und Olufsen school in Elk Grove Village, Illinois. During the indoctrination proceedings, we were made aware of the many innovations and inventions B&O has made to the audio industry over the years. I don't remember any of it now but I recall that the list was very impressive.

Another matter to keep in mind is the fact that many audiophiles are not programmed to absorb big losses upon resale and therefore feel safer buying items that have received high praise by the higher profile audio review pubs. Those are more likely to sell quickly and retain the most value.

If you like the Beolab 5, there is no reason to be dissuaded from purchase.

Of course, if anyone asks me, I always recommend my favorite.

You should also take a look at the Beolab 9. It's abou half the price and I have been told it is excellent too. I have not heard it myself though.

From this plot it sure looks as if the direct sound from the driver and the reflected sound from the frizbee above it are mixing. I was expecting or looking for this but it took me a while to find a plot so let me explain...

This is an effect called flanging and it can be quite pleasant as it creates an extremely spacious sound effect such that you cannot locate the source. This trick is well known and can be used to create the impression of stereo from a mono track. One signal is delayed by a fixed amount relative to the other and when summed you get the characteristic "comb filter". In this case the flanger is a fixed delay rather than a swept delay (like you get from pumping a guitar pedal).

You can tell this is likely going on from the characteristic sharp notches on the frequency response of the horizontally mounted drivers with frisbees: the dome midrange and dome tweeter)

I am surprised Tom Nousaine did not remark on this possible issue. He is an engineer and should have at least explained why it might not be a problem of this design.

Clearly the dome drivers are visible from the side and therefore the listener must be hearing two tweeters and two midranges: one directly and one delayed by the distance between driver and the frizbee that it reflects from. The fact that some reviewers have reported being baffled that even a lone BeoLab 5 speaker makes it hard to detect the source of the sound is a dead give away that this might be happening: the spacey rock guitar sound. Since the tweeter is aimed upwards at the frizbee then this signal will be much stronger than the one radiated sideways directly from the driver to the listener, which means the notches will not be that deep (as seen on the plot).

I am sorry to say but this design fails the basic acoustic physics back of the envelope test. I remain flabbergasted by the outstanding reviews - perhaps I am completely missing something? Ironic that a spacey looking speaker might also make a "spacey sound".

YMMV, this is conjecture as I don't have these speakers available to me in a lab to test out what appears to be happening. Perhaps B&O have a perfectly reasonable explanation of how they deal with this design issue, in which case I would apologize for my erroneous ramblings/conjecture.

Shadorne - Scores of people who HAVE HEARD this speaker think it sounds great, yet, you who do not say that you have heard it, theorize that it cannot work.
Aren't you one of the people who cautions everyone never to buy a speaker without hearing it in their own system? Why in god's name would you suppose to know of a deficiency that you have not heard? What motivates you to caution against something you are guessing about?