Here is a question I asked my dealer but which they were unable to answer. The dealer was demonstrating the Beovision 9 to us and wanted to demonstrate how the sound from the accoustic lens speaker is the same in all directions, or rather wherever you are in the room. He did this by turning the system to just one speaker and then turning the Beovision 9 on its stand. No matter where it was pointed the sound was the same. It has always been my understanding that the big benefit of the accoustic lens technology is that wherever you sit in the room, the sound will be just the same, it will sound non-directional.

In a home theater set-up one wants directional sound. A sound from the front left should sound like it is coming from the front left. Sound should pass from one speaker to another as the action on screen and the accompanying sound moves from left to right, front to back, etc.

How does one get the directionality when using the accoustic lens technology as it is suppose to eliminate the sound sounding different in different positions? Does a front left sound really still sound like front left from a Beolab 5 for instance?

 

Thanks!

I think you're getting dispersion and origin of sound mixed up!

With normal speakers, as you move around, you get a different sound from the speaker. Try standing in front of a normal speaker, and then move left and right. You can hear how particularly the high frequencies change in relation to where you are positioned. The sound quality of the speaker changes as you move around and listen to the speaker from different angles.

An Acoustic Lens is designed to prevent this. The sound still has a 'source', it still originates from one position just as with a normal speaker. However, where it is different, is that it's spreading out the sound through 180º rather than just firing it straight out of the front of the speaker.

Liken it to the difference between a very focussed beam of light (normal speaker), and a very evenly spread out beam of light which doesn't change in brightness as the source begins to point away from you (acoustic lens speaker). You can still see where the light is coming from, but it remains the same 'quality' as you look at it from different angles.

Hope this explains clearly! It's actually kinda difficult to explain...

Alex is right here. The source is evident, the dispersion just a benefit, in that the lens spreads a comparably equal weight of sound wider than will a regular loudspeaker driver. This means that it's not just the person in the sweet spot who gets the best sound - it's also possible to get a good soundstage seated in other positions, when receiving sound from acoustic lenses.

However, B&O marketing copy has tended to exaggerate the "place them where you want" aspect of these speakers. That's not the case at all - if you want a true audiophile experience, then exact placement listener, speakers and surroundings is important.

Acoustic lens speakers are not source "invisible" - if they were, then you wouldn't get anything like proper placement of elements in a soundstage. Yet with the three speakers you list, I can clearly hear which instruments and vocals are left or right of one another -- and I also get a very true sense of the depth of the sound image, which I think is due to the fact that the lenses prevent reflections off the ceiling and floor before the sound reaches you.

That said, I make a point of aiming them towards me when positioning AL speakers, in order to focus the source. (Something which I noticed they  do with the BL5s in the BeoLiving room in Struer).
 

soundproof:

That said, I make a point of aiming them towards me when positioning AL speakers, in order to focus the source. (Something which I noticed they  do with the BL5s in the BeoLiving room in Struer).

I find this a little surprising. I thought there was no need to toe in AL speakers. With non-AL speakers, the difference between toed-in and not toed-in is easyly audible. Does the difference stay that big with AL speakers?

No-way near as big as it is with non-AL speakers, but it's still noticeable. I find when toeing in BeoLab 5s though, there is a change in sound, but I actually prefer the sound non-toed in...

Alex:

No-way near as big as it is with non-AL speakers, but it's still noticeable. I find when toeing in BeoLab 5s though, there is a change in sound, but I actually prefer the sound non-toed in...

If I remember correctly, David Moulton does not like toe-in on ALT speakers, and he wasn't a fan of the toe-in at the Struer BeoLiving room. I asked about the toe-in when I was there, and was told that they had found it gave even more focus. Could be down to the physics of the room, though.

You will remember that I have the ultimate toe-in of the BL3s - and am very happy about it. Kind of fun when friends sit down between them and go "Fantastic!" It's a matter of personal taste and preference. But when I did listening tests with the BL5s people who sat right next to the person who was seated in the center reported getting a better, fuller sound when they were in that position, as compared to being less than a meter out.

I think the point is that the lens' can geometrically achieve, if so designed, a toe-in dispersion (up to 30 degrees I believe) while the speakers are apparently pointing straight into the room. I'm not sure if this actually applies to the BL5's though.??