Eliminating the sweetspot

[Brandon B]

Researchers using fuzzy logic to provide the same surround experience to various positions.

BB

[Chris D]

Interesting stuff, B. Not sure how that would really work.

I took a LOT of notice, though, following a link buried in that news blurb, that says that this technology is coming out in the new Denon 5805 receiver due out in the next few months!

[David Meek]

Stay the he*l away from my sweetspot!!! :

[Brandon B]

You don't want it touched by something fuzzy?

BB

[David Meek]

After reading the article it does sound interesting, but I have one issue with this whole thing:

How do they translate the measurements taken at multiple points into a sweet-spot-for-all without modifying the physical environment? Ie. adding speakers or acoustic treatments, or modifying speakers (or all of the above)? Or, without averaging the responses and consequently losing something at the original sweet spot? Without some kind of physical change, the programming can do all sorts of neat things in the "mathematical" environment, but then this program/receiver will be pushing sound out of the same speakers in the same locations already established in peoples' rooms. It seems like they are talking modification of the actual soundwave and its behavior! Huh? 8O

To me the only thing that makes even a little sense is to modify the timing of the output of di-pole speakers to modify the shape of the null created, but then that would be very dependent on indvidual speaker design.

There was one mention of a 10.2 sound system, but it's unclear whether they are requiring that type of set-up.

What am I missing here? Help! :sos:

[Kevin P]

I would think a system like this could *move* the sweet spot from one location to another, but not provide the sweet spot to multiple locations at once. But then it depends on what they refer to as the sweet spot. Normally that's the spot where the speakers image the best, and that can't be more than one location unless you have a very large room and lots of speakers... maybe that's the 10.2 idea.

I have a 10.2 design that gives you two sweet spots, and no new technology required. Install a 5.1 system in two different rooms!

[Gordon Moore]

I would think a system like this could *move* the sweet spot from one location to another, but not provide the sweet spot to multiple locations at once

Denon seems to think otherwise

The AVR-5805's state-of-the-art Auto Set-Up and Room Correction feature go well beyond conventional room calibration methods, and makes it possible to completely customize the listening experience for any room. The AVR-5805 incorporates a new room correction and calibration technology called Audyssey

MultEQ™ XT from Audyssey Laboratories. It is the first such technology capable of minimizing the effects of room acoustics for multiple listeners. During Auto Set-Up MultEQ XT automatically determines how many loudspeakers are connected, whether they are connected in phase, and whether they are satellites or subwoofers. It then analyzes and calibrates speaker level, size, and distance. In addition, MultEQ XT detects the proper crossover point and determines correct frequency response for up to eight listener positions simultaneously. It creates an optimized soundfield and compensates for speaker and room capabilities. So there is a “sweet spot” for every listener or viewer, no matter where in the room they're sitting.

Denon’s implementation of MultEQ XT utilizes multiple Aureus high-performance DSP processors from Texas Instruments, along with the finest Digital to Analog converters, to define optimum sound quality. Additionally, both the Room EQ and Auto Set-Up features can be disabled for installers and consumers who prefer to calibrate their receivers in the traditional manner.

Marketing BS....maybe

[Gordon Moore]

But then it depends on what they refer to as the sweet spot. Normally that's the spot where the speakers image the best

well:

http://imsc.usc.edu/news/releases/audyssey.html

"Audyssey's MultEQTM technology turns every seat into the 'best seat in the house,' breaking through today's 'sweet spot' limitation, where only one seat gets the best sound," according to IMSC key investigator Prof. Chris Kyriakakis, an Audyssey Co-founder and Chief Technology Officer.

"Now, with MultEQTM, the entire audience is in the 'sweet spot'-everyone can hear the same high-quality sound, no matter where they are sitting in the room," he said.

It would seem, Kevin, that your definition of sweetspot is in alignment with theirs.

[Burke Strickland]

Sounds interesting, but almost "too good to be true". They don't really explain how the sound coming from the same set of speakers could be optimized differently for up to eight listening postions simultaneously, but then that's probably info they don't want unlicensed competitors to have access to. Of course, there is alternative technology that could be guaranteed to provide every listener with the same high quality sound without their proprietary "fuzzy logic" or a 10.2 speaker array -- give each of them Dolby Surround headphones. :>)

Burke

[Brandon B]

I do think they are talking about surround imaging, which seems to me to be slightly different from stereo imaging.

BB

[Gordon Moore]

True...

With physcoacoustics....what the ear "hears" and what the brain "thinks" it hears are 2 different things so, maybe this trick is possible. I think Brandon is right though that this is specific to surround imaging.

Sounds similar to how Dolby came up with it's algorithm but it has been taken a step further.

Sort of Virtual Surround on steroids.

Sounds pretty cool.

[Burke Strickland]

I agree that stereo imaging is different from surround imaging. That is one reason a room "optimized" acoustically for two channel sound can be too "live" for the most effective presentation of suround sound, while a room deadened acoustically to allow the only reverb to come from the surround speakers as provided by the decoding algorithm are not at all suited to two channel music reproduction.

Even in rooms where the surround system "has control" (e.g., not a lot of room-effect reflections adding to what the system is generating), the surround effects can be skewed based on seating postion as described in the article, which is ample justifiation for implementing the "fuzzy logic" system, if it really works. It will be interesting to hear it in a real world setting and be able to judge for ourselves whether it is truly effective, or just marketing hype. I hope it really works, and if so, that it becomes widely available at a reasonable cost to consumers.

Burke

[Lex]

I found the best thing to do with a sweet spot is put a chair right in the middle of it and sit down. It does help to turn some music on too,.

Lex

[Chris D]

I thought people generally like to stay OUT of the wet spot. To each their own, I suppose. :roll:

Oh, you said SWEET spot!

[Lex]

chris. Just make sure your on the wife's side, hahaha.

Lex

[aarsoe]

Fact of the matter is that product "altering" the sound have been out there for some time - and they have mostly been given high praise. Think of products like TACT.
Now they are expensive, but we all know that cpu power is dropping dramatically in price every year - so I guess that it is only natural that we will see theese functions incorperated in almost all products sooner, rather than later.

I myself are happy about the idea, if more people can get better sound for less money, then it will hopefully also push the boundary for the good stuff, both in terms of sound, but also in terms of price.. And that will be a good thing for sure..

[David Meek]

product "altering" the sound have been out there for some time - and they have mostly been given high praise. Think of products like TACT.

True. BUT, what hangs me up is this product is talking up a (as I interpret it) gross physical change in the sound wave - "bending it" is a simplistic way of describing what I'm talking about - not just modifying the sound with response to a room curve at the listening position. Two different things entirely.

[aarsoe]

David

I agree - however I hope that the techies will realise that there is a limit to what you can do - even with cheap cpu power availeble.
But to get back to my point, the new "digital" amplifiers can be made cheap, and apperently they are not too shaby sounding - at least when compared to similar priced traditional amps. This combined with "on-the-fly" room adaptive measures will (I hope) bring a much better sound to most people that today live with something that makes most standard car stereo sound like the ultimate high end.. And if the masses get better sound, then the bar is clearly raised for the "drug lords" that supply our daily fix..

So I am confident that we will see better products across the entire price range based on this.. But, I am an optimist by heart..

[purplepeople]

"Sounds" like a new form of SRS. Play back the right harmonics and the brain interprets as coming from specific directions. Psycho... acoustic to me.

ensen.

[audyssey]

Audyssey MultEQ

Hello,

I recently ran across this thread. I would be happy to answer questions about our MultEQ technology. Please be assured that I will try to stay away from "marketing BS" as one of you stated.

Regards,
Chris
CTO Audyssey Laboratories

[Chris D]

Wow, cool... how does this work? Do you really get the best "sweet spot" experience in every location? Or does it diminish the performance of the true "sweet spot" to equalize each location? Do you have to specify which spots in your room to equalize, or will this system give you a "sweet spot" location ANYWHERE in your room?

[David Meek]

Hi Chris, welcome to The Guide. :welcome:

I suppose I'll start my questions off with an earlier paragraph of mine. . . . Thanks for taking the time (and suffering the exposure) to help us out with this.

How do they translate the measurements taken at multiple points into a sweet-spot-for-all without modifying the physical environment? Ie. adding speakers or acoustic treatments, or modifying speakers (or all of the above)? Or, without averaging the responses and consequently losing something at the original sweet spot? Without some kind of physical change, the programming can do all sorts of neat things in the "mathematical" environment, but then this program/receiver will be pushing sound out of the same speakers in the same locations already established in peoples' rooms. It seems like they are talking modification of the actual soundwave and its behavior! Huh? 8O

[audyssey]

Hi Chris,

The media write-ups try to oversimplify the issue. Here is what you really get:

With a microphone you measure several locations in the room. The goal is to measure a number of points so that the area inside those points is calibrated.

MultEQ gives you the desirable frequency response (defined by a target curve) in that entire area. In fact, we have shown in our research that not only there is no compromise of the single sweet spot, but it makes that better as well. The main reason for this is that equalization of only one location in the room causes other locations to actually sound worse.

This is the fundamental difference between MultEQ and the other methods. We can deal with multiple locations in a way that addresses the problems in each seat in the best possible way.

MultEQ also does other things like find the optimum crossover frequency between each of your speakers and your subwoofer(s), detects if speakers are wired out of phase, sets the levels, and sets the delays. The delays are set for the main listening position only, as it is physically impossible to have different delays for different seats out of one loudspeaker.

I hope this helps.

Best regards,
Chris
CTO Audyssey Laboratories

[audyssey]

Hi David,

Some of what you are asking is in my previous reply to Chris.

MultEQ does not modify the environment or the speakers. That would not make it very practical. It relies on measurements at various points in the listening area, but, as you correctly point out, it does not combine them by averaging. That would compromise several things. MultEQ applies a complex set of fuzzy logic rules to combine the responses from each speaker into one that best represents the problems at each location.

The result is a set of filters that undo the effects of the room and the interactions of sound from the loudspeakers with nearby surfaces.

Best regards,
Chris
CTO Audyssey Laboratories

[purplepeople]

So the method is based on feedback... does it require real-time measurements or a one-time calibration?

ensen.