Beolab 5 - Four Questionable Technologies

How much space was there between the speakers and the side walls?

About 3 feet - so enough not to ruin the image.

If you want to listen for imaging and soundstaging, then sitting in the sweet spot (equidistant between both loudspeakers) is essential in my opinion.

Correct. You should indeed listen in the center to maximise the imaging experience and especially when making evaluations. On reflection I agree that you have a good point. My point about 10 db is actually referenced in the link I gave....

The Haas Effect is, simply stated, a factor in human hearing where delay has a much bigger effect on human perception of direction than level does. Helmut Haas in Germany showed that although identical audio sources sent to two speakers at equal level resulted in a center image, a 5 - 20 ms delay to one of the signals shifted the image to the non-delayed side, and the delayed side had to be made 10 dB louder to get the image to shift back to the center. This is also called Precedence Effect.

Shadorne,

Right *after* I had submitted my question to you regarding the positioning of the BeoLab 5 during your audition, audiogon posted this from you.

"In my audition they were about three feet from the corners - so to me the congestion was from the speaker not the placement."

Based on this, I must say that the it's no surprise that the speaker sounded so disappointing. To place an omni speaker three feet from a corner where the side-wall is made of a highly reflective material like glass is nothing short of a disaster. Honestly, the people in the B&O store should have known better. That's about as silly as putting a set of QUAD ESLs 3 feet from a front wall that's made of glass. It's so ridiculous that it boggles the mind.

One must consider that unlike a conventional box speaker, an omnidirectional speaker is radiating almost full-range in all directions. The amount of reflected energy coming off those glass walls would have definitely caused smearing of musical detail and this would almost certainly be a prime contributor of the diffuse sound you heard.

In comparison, a conventional box speaker may be close to flat across its frequency range when measured on-axis and up to about 30-degress off-axis, but as you go further off axis the amplitude of the radiated energy starts to fall off non-linearly across its bandwidth. Therefore you may get away with putting a front radiating box speaker 3 feet from a side wall (although even here, some acoustic damping from furniture or curtains would be helpful), but the same configuration for an omni speaker is just silly.

To quote from Don Morrison: "Yes, the speakers should be brought out from the side and back walls. And yes, there should be room treatment on the side walls to tame the first reflection".

Shadorne
About the B&W 800D speakers you wrote:
“Yes do buy these over the Beolab - far better, IMHO. This is a fine speaker. A bit hard to drive but with the right SS amplification they will sing….this is an absolutely outstanding speaker. World class.”
I am tempted, and I don’t mind buying a powerful amp to drive them.
At the store they were using the 400 Watt Classe CA-M400 Monoblock Power Amplifiers. I have to admit I liked the way they looked and looks matter to me as much as the sound.

However, we are doubling the price here. The Beolab 5s are listed as $18,000. On the other hand, the B&W 800Ds list for $23,000 and if I go with the Classé amp and matching preamp (the Classé CP-500) that would come to $37,500. I can accept that if the sound truly is much better. I need to go back and listen again, but I on my first try the B&W speakers sounded more natural; more real.

I would like to hear the Wilson Watt Puppy 8 speakers and the Revel Ultima2 speakers. Other suggestions? I already tried the Vandersteen Model Five speakers and found the bass response oddly “boomy.”

Marty,
“this speaker would require an in-home demo and a large listening room. I don't know if B&O would accommodate such a request.”
B&O has already said yes to my request for an in home demo, even though I live 2.5 hours from them on a farm in the middle of Missouri. There will have to be some sort of payment if I don’t buy the system. Same with the B&W dealer.

“BTW, I can't state with confidence that the Beolab 5 doesn't image (soundstage) well.”
I wonder what others would say about this. I went back to David Ranada’s review in Sound & Vision: “it can produce good stereo imaging from a very wide listening area and extremely good imaging when heard from a prime listening position.”

Does anyone else have experience with this speakers imaging qualities?

Johnk,
" Will advancements in dig amps and DSP make it primitive in the near future?"
I'm guessing that if it sounds wonderful today, that it will continue to sound wonderful for a few decades regardless of how much digital amps and DSP improves.

However, I agree with your concern that about how well they might respond to a voltage spike. These are remarkably compact and complicated speakers. A lot is inside there and I expect repairs would be expensive.