@Mika - how long before they expect us to install a ceiling channel, as well?

In fact, moviemakers would love it if you did. All the surround speakers are supposed to be up on the wall, well above the heads of the people listening. Having the surround speakers at head level, to the side and behind, is wrong from the mixing perspective that one attempts to create ... Have a look in your local moviehouse on your next visit, and you'll see that the surround speakers are up on the side and rear walls. As these speakers are often used to create ambient sounds and "atmosphere" - it really does open up the perspective if they're also correctly placed at home.

(I just dented the B&O floor stand for rear speakers market!)

@koning - I've been told correct me if it isn't true, that this would end up in incorrect fase behaviour.

I feel that I can hear the phase manipulations distinctly, both in Q-sound effects, and in other ways of projecting sound from one or very few sources. Most bothersome.

The moving sweetspot possibility also potentially suffers from this, but with today's fast processors one can write algorithms that check for potential phase distortions and cancel these through processing, before the signal is sent to the four speakers.
Whether you really want a moving sweetspot is another matter - you could always get a pair of wireless headphones!

But I do believe that we'll see person-dependent multiple sweetspots, preprogrammed, from a certain audio company soon, according to rumors about the BeoSystem 3 upgrade.

Interesting!

Will there be in the next version of the system 3 a microphone input for calibration.

or is it something else?

soundproof:

thavn writes: Are you serious? I have BL5 in a surround setup with my Avant as a centre speaker. It works ok, but could have been better. I am considering buying a BV7 with BL7-4, but the 7-4 speaker makes the set a bit too tall for my wall (I have two paintings over the TV that can´t be moved).

I am completely serious. I belive B&O missed an incredible opportunity here. Better processors (faster and more accurate) are making processing audio for surround much simpler, delivering better results.

Unfortunately, B&O surround setups in tv's, media players and the BeoSystem 3 do not allow for assigning the centre channel signal to the front L/R channels, which means that in order to experience the brilliance of the phantom centre that can be generated by acoustic lenses, one has to use a processor from another brand. I have tried various surround processors and pre-amps, and with excellent results. I would really not accept a compromise here, and have absolutely no impression that I am getting a compromised centre channel with my BL5s creating a phantom centre.

The centre channel speaker is an eyesore and a bother - ideally it should be behind the screen (which it is in cinemas), but we end up either having it too low or too high, and if you have a movie screen dropping down, you get a potential additional bother. Which is why I feel that B&O could have played a better hand here - it would have been a major selling point for acoustic lenses. It's really worth trying out!

Soundproof,

I have a "low-end" B&O stereo A/V set-up (BV8/BL3/fed by ATV and Tivo) and I will say that the "position 3" setting (i.e. BL3s and BV8 cabinety speakers) on the BV8 is far superior when viewing any sort of video than when using the "position 2" setting (BL3s only). In fact in surround movie content, conversation is nearly inaudible without the center speakers. This is one, perhaps not common, example where the center speaker is important in A/V applications independent of the presence of ALT. I personally do not like the present A/V surround systems unless installed in a room specifically for that purpose. Even in this case, the sound is so "boomy" as to be entirely artificial. Having been very close to significant explosions (as a scientist investigating impulse acoustics) the current version of explosions being replicated in surround video are well off the mark. Other similar, high impulse, acuostic events in such material also suffer.

I find the ALTs to be very accurate (compared to a concert hall) for detail in music when the transducer is placed at about ear-level for listening and have yet to find any other approach that is close. I am hopeful that B&O are continuing in their quest for improved reproduction by participating on the frontier of this technology. They certainly made a landmark product with the BL5 (and it's derivitives). BTW thanks for the lecture.... very interesting, although "air" is not best modeled as "particles" at acoustic frequencies. Fluid dynamics is more appropriate.

Affineur:

Soundproof,

I have a "low-end" B&O stereo A/V set-up (BV8/BL3/fed by ATV and Tivo) and I will say that the "position 3" setting (i.e. BL3s and BV8 cabinety speakers) on the BV8 is far superior when viewing any sort of video than when using the "position 2" setting (BL3s only). In fact in surround movie content, conversation is nearly inaudible without the center speakers.

This isn't related to center speaker, this is a typical issue with B&O surround modules : the "position 2" is only meant to be used for stereo signals, as there is NO phantom center processing in ANY B&O surround (or in this case stereo) system. If you use a 5.1 material with your BV8 and use "position 2", the center signal is just not routed to the front left & right speakers. Soundproof already pointed that one has to use a 3rd party surround processor to benefit of the good phantom image of ALT speakers. Using position 4 or position 2 on 5.1 (or 7.1) material with a B&O surround processor is just totally pointless.

Interesting you should say this actually, track 4 of the Active Listening III CD is an amazingly good recording of Maurice Derufle's Ubi Caritas. The original recording was actually recorded in 6-channel surround sound and is available on SACD. The 6th channel is for a speaker placed above the listening position.

It's something I'd quite like to try out at some point. It would be difficult to achieve with ALT loaded speakers though as they are quite clearly useless when used as an over-head speaker (a 3D symmetrical cardioid distribution pattern is what's really needed).

TripEnglish:

The idea of the lenses rising from the 8000s specifically is just not going to happen. They would place the lens above the listening position, anyways. However, Soundproof is correct that the idea of a lens folding away is not out of the question. I know for a fact that an upcoming speaker concept incorporates this. Magical motion is one of the core design principals of B&O. If it's good enough for a dashboard it's certainly good enough for my living room and the chances of something being done tastelessly in a B&O product is fairly slim (unless it also carries a Samsung logo).

When will we see this new loudspeaker Trip?

I believe mbee has it right here, affineur. You were listening to the bleed-off to the L/R fronts, without the information in the centre channel signal - because of this limitation in B&O surround processing. I guess some beancounter decided that in order to be able to sell centre channel speakers, they wouldn't allow a no centre channel option.

Yes, it would be nice if the BV8 had a more advanced sound processor, but this would likely affect the sales price and may have been a consideration. The system does offer examplary performance for baoth audio (BL3s only) and video (BL3s + BV8 speakers) in a non-surround application. I am hopeful thatn the new sub will be a more accurate transducer than the BL2 as this "low end" system could use a bit more low end for certain sources.

Given the ease with which the ALTs will accurately reproduce the "center channel", perhaps B&O will include such in the next gen video/processor products. I am, howver, surprised that they would not have offered this instead of a new center speaker for surround applications. I expect that they have some sort of argument against it either sonically or operationally.

I'm very pleased with my BV8, and have used it as you have, with BL3s. It's an excellent television - would have been perfect with surround processing.

Well the 40" version will have a surround processor...

Would it be the same surround processor as in the BV7-32

Alex:

The centre channel mix at the cinema can quite easily be mixed into the output from the main speakers creating a 'phantom' centre channel. I'm not sure how Goldmund can 'build in a centre to both the left and right channels', isn't that just called mixing the signals together?

For the Goldmunds, there literally are centre channels built into the L&R channels. So instead of one centre channel, you have 2. Meaning you have 2 speakers for each side. 

Wonderfulelectric is correct here. Goldmund doesn't believe in the centre channel - which is kind of a special statement, as long as movies are mixed with one. But their reasoning makes sense - they feel the centre channel, even with a proper movie projection screen that is perforated to allow the sound to bleed through, is just not right, and that their solution (with a phantom centre) is better.

A nice run-through of the principle here: http://www.goldmund.com/technology/th3/

As stated above, this is an area where I feel B&O missed the boat, as the acoustic lenses could have created some buzz for an alternative solution from the company. Goldmund has spent quite some time working with the sound processing, in order to achieve perfect time alignment of all the drivers in their setup, and in order to avoid phase distortions.

Goldmund's principle is called TH3 (THEATRE3) - the BL5s can emulate the same, as they have the subwoofer/woofer built-in, and can generate a phantom centre, with perfect timing and phase alignment - though not with a B&O surround processor. :

Unfortunately, to my eyes, Goldmund's speakers look like something you'd find in a gym, with weights.

Goldmund's side and rear surrounds are more conventional than what's shown in the sketch, but they are always correctly placed, up on the wall.

Hmm, looks like somebody has taken the phantom whatever idea further and gotten away with the three speakers per setup idea... sounds familiar...

Seriously, do we have to call summing and subtracting "processing"?

Well, we do speak of surround sound processing, and the hardware is called surround sound processors ... it's not the number of speakers that is being referred to, but the work performed by processors applying algorithms to digital files, before these are converted to analog signals that are passed to the speakers.

http://www.hometheaterhifi.com/masterindex_surround_processors.html

Agreed! It's hardly processing.

Having said that, if it is done by the DSP stage, and two 24 bit signals need to be converted and the output converters run at 24 bit depth, some processing will need to go on to reduce the volume etc...

Still not exactly a huge task...

Ah, I get it. You're thinking of passive systems that just pipe the signal on? Today's home theatre processors perform quite a lot of calculations on the signal, particularly those that perform measurements of the room, in order to achieve the best possible sound, with an absence of room nodes, phase-outs, etc. And that takes a lot of processing, but with good results.

Here's what Jens Abildgaard Pedersen, one of the co-inventors of BL5, has been working on since he left B&O. He did the low-frequency room calibration, and was in charge of the project:

http://www.aes.org/sections/uk/meetings/a0611.html

soundproof:

Ah, I get it. You're thinking of passive systems that just pipe the signal on? Today's home theatre processors perform quite a lot of calculations on the signal, particularly those that perform measurements of the room, in order to achieve the best possible sound, with an absence of room nodes, phase-outs, etc. And that takes a lot of processing, but with good results.

I understand and appreciate all that, my focus was still just on the phantom center channel. As far as I can see, the basic "processing" is this:

• take a center channel sample
• shift it to right one bit (to divide by 2)
  
• add it to both L and R

...and that's it. This part in digital domain could be wired on a euro sized PCB with 74 series TTL chips from the 70s with no DSP at all, and an analogue implementation would struggle to fill a small breadboard

In practice, I would probably want an adjustable delay to virtually move the "center speaker" back and forth and a level adjustment, but it's still not rocket science. Sorry if I mislead you to elaborate, I always enjoy reading your posts (and will follow those links when I have better time, I can't call myself educated on home theatre specifics).

Thanks, Tournedos. Yes, controlling the centre-channel signal is not very difficult, and it should be possible to include this in an upgrade.

BTW - always be careful with using "not rocket science." Here's a true story. A manager from a leading European telecommunications company was in Russia, where they were going to enter into a venture establishing a communications link that included satellites. The manager said "Well, after all, this isn't rocket science."
A voice from the audience, in accented English, responded: "We're all rocket scientists, and you're right, this is not rocket science."

Ever thought maybe the phantom centre channel will need to arrive to the listener first before the left and right to create a more realistic centre channel reproduction? 

No, all channels should arrive at the listener at the same time, hence why surround sound decoders have options to set speaker distances to compensate for speaker placement.

Just as a stupid thought.....

Could one simply install a Powerlink Y-Splitter, and connect the Centre Channel powerlink to the splitter, then onto the second powerlink input on a pair of BL5's?

The dual signals (assuming no clasing of signals) would be mixed in the BL5's powerlink board before going to the DSP. The Beovision would still do the mixing and the timing adjustments.

Just a silly thought for all those wishing to experiment.

10%

I'll revive this topic, since I just took a look at what I'm supposed to be studying

All this phantom channel stuff is, obviously, pretty much old news at the time you can start buying them in shops:

http://www.acoustics.hut.fi/research/cat/vbap/

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