dialogue on every speakers in AST mode ?

I have noticed that when I play a bluray the dialogues are coming from every speakers with AST on.

In the sound configuration a center speaker is selected.

According to you is it normal ?. I tried several blurays.

It does not on my BV7.

Razlaw:

It does not on my BV7.

Thanks for this info.

I have read this post :

http://archivedarchivedforum2.beoworld.org/forums/t/33197.aspx

"When AST is switched on there is no longer a speaker 1,2,3 etc option, indeed Front left/right etc no longer exist. There are simply loudspeakers that play sound and depending on their position they might play a bit of centre channel, a bit of front channel or even a bit of surround channel as well to give the total illusion of a correct surround sound placement. "

So it could explain why I hear dialogues on every speaker.

As geoff said in this thread :

"You gain flexibility in loudspeaker placement, listening position placement and the direction you're facing. However, the "price" of this is precision. If you're looking for precise localisation, distance and depth in your stereo/multichannel image"

In ast mode I have the impression to be in the heart of the action like in a cinema but loose a lot of sound localisation.

Personnally I love that.

In a real word when the action is important and sounds are fast, loud and in several directions at the same time, there is no precise localisation.

The fact that my listening position is nearer the center and front speakers rather than the surround speakers (2 meters of differences) and my room is very rectangular , should help.

olvisab:

According to you is it normal

This is normal.

When AST is on, every channel comes from all loudspeakers. The concept is that all loudspeakers are used to create a "virtual" loudspeaker for each input channel. However, although (for example) the centre channel is coming from all loudspeakers, it is doing so with different processing (including gain, delay and frequency response sculpting, to name the basic ones) applied to each loudspeaker. This is done for each input channel, so you can think of your system as a big NxM matrix where N is the number of input channels and M is the number of loudspeakers. For example, if you have a 5.1 input and 7 loudspeakers, then you have 6x7 = 42 different signals coming at you. . .

The effect vs. "price" comments you quoted from the earlier posting are still true, however. So, if you have well-placed loudspeakers AND you like precise imaging, you should turn AST off.

Cheers

-geoff 

BTW: Happy new year everyone.

Geoff Martin:

This is normal.

When AST is on, every channel comes from all loudspeakers. The concept is that all loudspeakers are used to create a "virtual" loudspeaker for each input channel. However, although (for example) the centre channel is coming from all loudspeakers, it is doing so with different processing (including gain, delay and frequency response sculpting, to name the basic ones) applied to each loudspeaker. This is done for each input channel, so you can think of your system as a big NxM matrix where N is the number of input channels and M is the number of loudspeakers. For example, if you have a 5.1 input and 7 loudspeakers, then you have 6x7 = 42 different signals coming at you. . .

The effect vs. "price" comments you quoted from the earlier posting are still true, however. So, if you have well-placed loudspeakers AND you like precise imaging, you should turn AST off.

Cheers

-geoff

BTW: Happy new year everyone.

Happy new year to you too and to all b&o workers !

Thanks a lot geoff for your 4 years explanations and this last final explanation.

This AST function is really great. I don't know if it is available on the bv 11 and avant, I hope so as it could be a real improvment in certain circumstances for all owners.

But I wonder if this positiv effect is not completely lost if there is too much difference between the front and rear speakers, bl5 with bl6000 or 4000 for example.

olvisab:

This AST function is really great. I don't know if it is available on the bv 11 and avant, I hope so as it could be a real improvment in certain circumstances for all owners.

But I wonder if this positiv effect is not completely lost if there is too much difference between the front and rear speakers, bl5 with bl6000 or 4000 for example.

The AST algorithm was not included in the new televisions since they have a new 16.5-channel upmixer instead. The effect is different, but the versatility is roughly equivalent.

An additional component of the AST algorithm is a correction filter applied to every loudspeaker that makes them more similar. As you know, it's madness to try to make a phantom image between two different loudspeaker models, so some corrective magnitude and phase equalisation had to be applied in the AST algorithm in order to get it to behave in loudspeaker configurations with more than one loudspeaker model.

Cheers

-geoff

Geoff Martin:

The AST algorithm was not included in the new televisions since they have a new 16.5-channel upmixer instead. The effect is different, but the versatility is roughly equivalent.

An additional component of the AST algorithm is a correction filter applied to every loudspeaker that makes them more similar. As you know, it's madness to try to make a phantom image between two different loudspeaker models, so some corrective magnitude and phase equalisation had to be applied in the AST algorithm in order to get it to behave in loudspeaker configurations with more than one loudspeaker model.

Cheers

-geoff

Thanks for these precise informations.

I am quite a lucky guy because the calibration of my beolab 5 and the AST give pretty good result into my home ... and I can pump up the volume and play it very loud without annoying my neighbours.