Beolab 5 - Four Questionable Technologies

"Not all conventional box speakers have narrow dispersion ( no side radiation ) - good speakers will have wide dispersion at least as wide as far as it matters (to be affected by side wall reflection to listener)."

Shadorne,

I think that the reason for our disagreement is due to the way that we're each using the term "wide dispersion". I am not disputing that there are conventional front-radiating speakers with wide dispersion, but it is a fact that all conventional front-radiating speaker will become increasingly directional as you go up in frequency.

To illustrate my point, please take a look at the polar response graphs in this website.

http://www.mcsquared.com/speakers1.htm

Notice how the bass is virtually omnidirectional even for a front-firing speaker, but the midrange and treble gets increasingly directional. This happens because the wavelength of sound becomes shorter and shorter as you go up in frequency, hence the sound waves cannot "wrap" around the loudspeaker. Yes, some front-firing designs manage to achieve exceptionally wide dispersion through a narrow baffle configuration, but in the end there is no way to cheat the laws of physics and a front-firing speaking will never be able match the broadband off-axis output of a true omni-directional design. This is why an omni speaker will always be more susceptible to early reflections from nearby surfaces compared to a front-firing speaker (even when compared to a front-firing speaker that has exceptional dispersion), thus greater care in positioning is required.

In the end, my point is that you cannot apply the exact same method of speaker placement to both front-firing speakers and omni speakers. Placing a conventional speaker 3 feet from an untreated wall may have worked for you in the past, but this just isn't going be optimal for an omni speaker. When you switch to an omni speaker, the difference in its radiation pattern simply requires a change in your thinking.

Oxia,

I agree. I do not like omnidirectional or dipoles or forward and rear radiating panels or ribbon speakers for the very reasons you give about the reverberation they create. It creates ambience at the expense of imaging and soudstage and clarity. BTW: I have soffit mounted my mains - so I have eliminated the nasty rear radiation in the omnidirectional mid bass (with its inherent quarter wavelength cancelations that the listener hears as a "comb filter", altering certain notes as it affects harmonic balance in the lower midrange) The improvement from soffit mount versus non soffit mount is significant - image and tangibility of sounds improve further and make for a very solid soundstage but most people would never bother to go to this much trouble.

I just noticed I was asked questions on your post.

1. I question that review, only because that particular mag never ever in my experience recommends something that expensive, and it is clear the author had a prior thing going on the design of the Beolab. But I question it mainly because they never,ever never recommend anything that expensive in that magazine, but then again, it may be that good. So I don't disregard it, it just strikes me as very strange.

2. I have no idea about the reviewer, except I generally believe most reviewers try to do a good job and he seemed fairly technically knowledgeable during the review.

And I LIKE omnis, because you are not nailed to a sweetspot ...and no matter what anybody says, the omnis I have measured have better dispersion than any box speaker I have measured, by a fair amount. It is a tradeoff if you are not sitting in an exact spot, which, I agree, will tend to be the absolute best measured place if a room is done right. The question is, do you want a solitary hobby or one you share... do you want to sit in more than one spot? If so, omni, if no... box.

Cheers!
Chris

Well, I have picked my speakers, and they are not the Beolab 5s.
I love the idea of the B&O speakers, but on careful listening, I have to say that the B&W 800D speakers appeal to me more.

Granted, with proper amplification they are about twice the price of B&Os Beolab 5 speakers. But they are more appealing to me. I've already ordered them.

But in time if B&O stays with their innovative thinking I think they will get it right.

Shadhorn,

You state:

" I do not like omnidirectional or dipoles or forward and rear radiating panels or ribbon speakers for the very reasons you give about the reverberation they create. It creates ambience at the expense of imaging and soudstage and clarity."

This is actually NOT the case with German Physiks - makers of the only full-range, single-element point-source omni driver. That is what really enamored me of the brand and why I took on the US distribution. UltraAudio just reviewed the HRS-120 model from GP, with Jeff Fritz observing:

They produced the most expansive, most three-dimensional soundstage I’ve yet heard in my room.

The sound was melt-the-walls-away wide and deep. The result was that the speakers truly "disappeared" from the music, leaving behind only some of the most beautiful sound I’ve ever heard.

The HRS 120s kept a stable image even when I listened a couple of feet or more off axis.

What I instead heard was bass that was reasonably extended ... with good speed and integration.

The HRS 120s could flat-out rock when called on to do so.

Germans Physiks loudspeakers have something unique: their sound. The Dick Dipole Driver, now virtually perfected, has been put to good use in the HRS 120, where it produces a sound that is quite marvelous -- I loved listening to these speakers.

You might just fall in love with them. If you do, I can just about guarantee that you’ll be the first on your block to have a set, and that your audiophile friends will gawk in amazement when they first hear them.

In my mind, the DDD driver is the most technically accomplished omni driver design extant. It is a "have your cake and eat it too" proposition, providing huge soundstaging, as well as proper and lifelike imaging. So far my experience has been that GP speakers are the only direct-radiating omnis to accomplish this feat.

(no - it is not just a present-day Walsh driver. Check out the DDD technology page on German Physiks' web site for the background:
DDD TECHNOLOGY

German Physiks speakers are probably the more expensive omni options out there, but they are invariably also the most highly accomplished.

Cheers!

Chris