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"Official" Audyssey thread (FAQ in post #51779) - Page 1236

post #37051 of 70896
The majority of the time I am in my theater, I am listening to music. And no one else is there.

I have calibrated my current Integra 80.2 with Audyssey Pro per the instructions on the Audyssey web site (I used 12 positions) and it sounds very very good (or maybe excellent).

Since it is just me most of the time and sitting in the MLP, would I hear or be able to measure a difference if I did an additional 12 or 20 or ??? measurements at the MLP. The current 12 positions only includes one at the MLP.

It would not be a lot of work to do so but if someone else has done it and found no difference, then I might not try it.
post #37052 of 70896
Quote:
Originally Posted by markus767 View Post

There's an AES Convention Paper 6614 "PHANTOM AUDIO SOURCES WITH
VERTICALLY SEPERATED SPEAKERS" by Shiva Sundaram and Chris Kyriakakis:

"ABSTRACT
Multichannel auditory displays and Immersive Audio Systems are frequently integrated with video displays. Often, in these applications, the video display placement makes it difficult to place the centre speaker in front of the listener. A solution to this problem is to create a phantom centre channel in front of the listener using speakers placed elsewhere. Conventionally, phantom sources can be created by amplitude panned techniques in the horizontal plane. However, since it is practical and aesthetic to have speakers above or below the video display, in this paper, we propose a technique to create a centre phantom at 0o elevation and 0o azimuth to the listener using two vertically separated speakers placed above and below the horizontal plane at 0o azimuth. The phantom centre is created using inverse filtering techniques. This technique can also be extended to create phantom sources in the median plane."

And the abstract of your post is that two vertically separated center channel speakers can work if "inverse filtering techniques" are used?

"Out if the box" I don't think that is happening, and I don't recall hearing about an Audyssey technology like that being introduced.

Jeff
post #37053 of 70896
Quote:
Originally Posted by kbarnes701 View Post

Hi SB - yeah, Jeff has put his finger on it, as usual (!) - the dreaded comb filtering issue. I'd forgotten all about that.

But then, markus quotes from a paper by Chris K that seems to imply it can be done. Thankfully, like you, I don't have this problem so, for once, things here are straightforward.

Kind Regards,

Keith

If one is able, an acoustically transparent screen ... a WOVEN one ... is the way to go.

Jeff
post #37054 of 70896
Quote:
Originally Posted by audioguy View Post

The majority of the time I am in my theater, I am listening to music. And no one else is there.

I have calibrated my current Integra 80.2 with Audyssey Pro per the instructions on the Audyssey web site (I used 12 positions) and it sounds very very good (or maybe excellent).

Since it is just me most of the time and sitting in the MLP, would I hear or be able to measure a difference if I did an additional 12 or 20 or ??? measurements at the MLP. The current 12 positions only includes one at the MLP.

It would not be a lot of work to do so but if someone else has done it and found no difference, then I might not try it.

I biased mine towards the MLP. I only have MultEQ XT (and MultEQ XT32 equivalent for my bass via the AS-EQ1) so I can only do 8 positions for the main Audyssey calibration (and up to 32 for the bass). Because I am more concerned with how good it sounds at the MLP and not so worried about how it sounds at my one and only other seat, I do 4 of my 8 calculations around the MLP and the other 4 around the rest of the 'bubble'. After trying it this way and the more conventional way, I find that the sound at the MLP is very good indeed but the sound in Seat 2 is less good - which is what I'd have expected I guess. I'd love it if my AVR could store two Audyssey calibrations, one for the MLP bias and one for when there are two of us watching a movie, but of course it can't.

I'd expect you would find a similar result if you biased your mic positions towards your MLP. HST, there are others on here who know a lot more about this than I do

Kind Regards,

Keith
post #37055 of 70896
Quote:
Originally Posted by CANNON-FODDER View Post

But the quoted abstract states: "The phantom centre is created using inverse filtering techniques." Wouldn't that imply that in the form that Chris contributed to, [room] correction was used to avoid the comb and lobe issues* being discussed? Also, we take it on faith that the subject of the paper is treated as preferred or acceptable, it could be that the results were spectacularly "meh". So, if the AVR folks did that it would be OK, but it Audyssey did not think it was appropriate or write the filter.

v/r,
C-F


* (Not an expert, assuming lobing means something like signal strength in antennas and combing is the phase cancellation, i.e. they are not the same thing...)

I would bet that if Audyssey had integrated a technology like that into receivers/processors we would have heard about it and there'd be a logo on the front. Plus, I'd guess that we would need to tell the receiver/processor that we had two CC speakers and maybe even the distance between them. On top of that, it might even be necessary that the two CC speakers be on two separate channels so that filtering could be applied on a per channel basis.

Just guessing here ...

Jeff
post #37056 of 70896
Quote:
Originally Posted by Tom Hilton View Post

I concur with this approach---my center speaker is also below the projector screen, and I've had to do this kind of thing for a long time.

Initially, I used the "wedgies", but later found a speaker stand that did the job just about perfectly. Its design is such that the bottom of the speaker rests on a round metal bar nearest the floor, with the speaker leaning against a second metal bar above but posterior to the lower bar. Physically sliding the bottom of the speaker backward and forward in the stand provides the user enough range to adjust the speaker's upward tilt. With a bit of experimentation, the desired angle with respect to the listeners' ear level can be established.

While experimenting with different angles for my center speaker, I became convinced that finding the proper tilt was beneficial for achieving the best possible imaging and balance across the front three channels. To my ears, varying the tilt of the center speaker significantly affected the sound up front and could be discerned across a variety of listening positions.

Of course, if your front three speakers have identical dispersion patterns and can be positioned on the same plane (perhaps behind the screen), all these considerations are of little practical value. On the other hand, if your center speaker must be placed below the screen, it is my opinion that establishing the optimum tilt is well worth the effort and will have a positive sonic effect.


Tom

Tom can you tell where you bought this speaker stand? I am lookgin for something like this for my center channle and would very much appreciate if you could link that website here.

Thanks

Sri
post #37057 of 70896
Quote:
Originally Posted by pepar View Post

And the abstract of your post is that two vertically separated center channel speakers can work if "inverse filtering techniques" are used?

"Out if the box" I don't think that is happening, and I don't recall hearing about an Audyssey technology like that being introduced.

MultEQ is a technique which creates and uses inverse filtering, or?
post #37058 of 70896
Quote:
Originally Posted by rickardl View Post

MultEQ is a technique which creates and uses inverse filtering, or?

Well, yes, but I got the impression that there was something more to the "technique" referenced than what MultEQ is doing. Beyond that, as MultEQ can't correct nulls, how the heck would it correct the cancellation that occurs with comb-filtering?

Anyway, I am glad that it will remain academic for me; my previous screen was a perforated one and comb-filtering was a huge problem .. and that was with one center channel speaker. A woven one has made it all go away.

Jeff
post #37059 of 70896
anyone have any pointers on using separate fronts with audyssey? i'm assuming it doesn't store separate curves for a and b fronts (my music and ht mains). anyone have a clever way of appx the calculated curves maybe over to the manual curve or some other method?
using denon 2809 btw, thanks
post #37060 of 70896
Wow, lots of interesting comments about using 2 center speakers ('over and under'). In any event, it's not something I would do because of the hassle. The Onkyo 'Screen Center Dialog' feature is a simple way to try to raise the center channel signal if one's center speaker is lower than ideal, but I don't think it's a big deal. I was not unhappy without it, but do find it (modestly) helpful. Again, for anyone who has this feature in their AVR it's a trivial matter to simply try it and see if they like it or not. (I would be interested to hear what some of the more knowledgeable audiophiles among you think about it AFTER you've tried it.)
post #37061 of 70896
Quote:
Originally Posted by audyssey View Post

MultEQ XT on Sub EQ
Sats: N/A Sub: 512x

It would have been nice if you would have confirmed this for me when I "asked Audyssey" last November, before I sold mine at a huge loss. What would have been even nicer would be if Audyssey had made people aware that this was happening. I was registered as a Pro Installer and heard absolutely nothing about it!!
post #37062 of 70896
Quote:
Originally Posted by mjf_uk View Post

It would have been nice if you would have confirmed this for me when I "asked Audyssey" last November, before I sold mine at a huge loss. What would have been even nicer would be if Audyssey had made people aware that this was happening. I was registered as a Pro Installer and heard absolutely nothing about it!!

Exactly what is your complaint? From what you've quoted, it is not clear.

Jeff
post #37063 of 70896
Quote:
Originally Posted by kbarnes701 View Post

I'd love it if my AVR could store two Audyssey calibrations, one for the MLP bias and one for when there are two of us watching a movie, but of course it can't. Keith

I use Audyssey Pro so I could have two different sets of measurements and load them at the appropriate time. I may give it a whirl and see what the other seats sound like. If they are too poor, I will have to figure out if I want to go to the trouble of loading new measurements (etc) to accommodate if it's just me or if others are in the room>
post #37064 of 70896
Quote:
Originally Posted by pepar View Post

Exactly what is your complaint? From what you've quoted, it is not clear.

Jeff

I sent an "Ask Audyssey" request on the 7th of November, one of my questions was:

"Now that MultiEQ XT32 is available and has a filter resolution of 512x, compared to 256x on the Subwoofer EQ, will the filter resolution of the Subwoofer EQ be increased to 512x?"

Chris replied with the following:

"There are no plans to upgrade the firmware on the Sub EQ products at this time."

It now appears that the update to 512x had already happened according to what Chris poseted here back in July:

http://www.avsforum.com/avs-vb/showt...7#post18895417

If he had said that the Sub EQ had in fact been updated to a filter resolution of 512x and let me know what version of the software was required to do this, it would have saved me from losing a lot of money selling the Sub EQ.
post #37065 of 70896
Quote:
Originally Posted by kbarnes701 View Post

Hi Al,

No - it was introduced on the x008 series. FWIW, and not for me to challenge millwerwill's findings in any way, Chris said he thought that it was a really bad idea to mix centre channel information with Height channel information - and went to some length to make it clear that this was an Onkyo invention and nothing to do with Audyssey . DSX specifically avoids taking *anything* from the centre channel when it extrapolates the information for the heights in order, IIRC, to preserve the integrity of centre channel information, especially dialogue.

I would have thought that a better way to get the centre channel 'up' a bit would be to run an identical additional centre channel speaker the same distance above the screen as the other one is below it. As the centre channel is mono, this would presumably create an image bang in the centre of the screen. Might have practical difficulties though. Personally, although my centre channel speaker is below the screen (just below it) I find that psycho-acoustics put the dialogue right into the mouths of the actors - presumably because visual information is interpreted by the brain as of a higher order of importance than audio information (just guessing there). It would also depend on the screen size - I don't have a PJ.

Anways, for you and me, it's academic - our x007 series AVRs don't have the capability anyway

Kind Regards,

Keith

Thanks for the clarification Keith, I thought it might be something to try if available, but I understand Audyssey's caveats about this process and as you say; a moot point with the NR3007 anyway.

Regarding your thoughts around the center channel, mine is quite low but I have never really been overly bothered by it's physical location, the screen I have is relatively large and the plan is to move the L,C,R behind it in the HT-Redux sometime in the future. I have 5 identical speakers for the front LW,L,C,R,RW and a smaller speaker from the same family for heights just waiting for deployment...
post #37066 of 70896
Quote:
Originally Posted by mjf_uk View Post

I sent an "Ask Audyssey" request on the 7th of November, one of my questions was:

"Now that MultiEQ XT32 is available and has a filter resolution of 512x, compared to 256x on the Subwoofer EQ, will the filter resolution of the Subwoofer EQ be increased to 512x?"

Chris replied with the following:

"There are no plans to upgrade the firmware on the Sub EQ products at this time."

It now appears that the update to 512x had already happened according to what Chris poseted here back in July:

http://www.avsforum.com/avs-vb/showt...7#post18895417

If he had said that the Sub EQ had in fact been updated to a filter resolution of 512x and let me know what version of the software was required to do this, it would have saved me from losing a lot of money selling the Sub EQ.

I can't speak for Chris, but initially there was some confusion over the "X-factors" and how XT 32 lined up against the SVS AS-EQ1 and Audyssey Subwoofer Equalizer.

I have read that they have no plans to upgrade the Sound Equalizer ... maybe he was thinking about that unit ... ?

Jeff
post #37067 of 70896
Quote:
Originally Posted by pepar View Post

There is comb filtering with two center channel speakers .. one above the screen and one below the screen, and that is the concern I believe with one center below and shouldering the CC signal to the two Heights.

Jeff

I wasn't even aware of what comb filtering was so I googled it. I found this one link explaining it and also saying it wasn't anything to get worried about since essentially your brain/ears compensated for it. http://forum.ecoustics.com/bbs/messa...79/572305.html He also cited Floyd E. Toole as verifying this in his book.

I want to say I'm NOT an expert nor did I have any prior knowledge really on comb filtering. But it's interesting his claim that this shouldn't be a factor in what you "hear" once it's filtered by your brain.
post #37068 of 70896
Quote:
Originally Posted by Al Sherwood View Post

Thanks for the clarification Keith, I thought it might be something to try if available, but I understand Audyssey's caveats about this process and as you say; a moot point with the NR3007 anyway.

Regarding your thoughts around the center channel, mine is quite low but I have never really been overly bothered by it's physical location, the screen I have is relatively large and the plan is to move the L,C,R behind it in the HT-Redux sometime in the future. I have 5 identical speakers for the front LW,L,C,R,RW and a smaller speaker from the same family for heights just waiting for deployment...

My screen, unfortunately, is only a 50 inch Pioneer Kuro. By 'unfortuately' I mean the size not the fact it's a Kuro! My room won't accommodate a PJ I'm afraid. So my centre speaker is under the screen but the distance from it is nowhere near as great as it would be for a large PJ screen. I think psychoacoustics will come into it and your brain will 'shift' the dialogue into the right place thanks to the utter dominance of the visual senses over the auditory senses. It may be one of those things that, once you've noticed it (the dialogue not being centred) you always hear it like that for ever more.

Get those Heights deployed Al!

Kind Regards,

Keith
post #37069 of 70896
IceTBC,

His context is in speaker design, not two CC speakers above and below. Plus, I had comb filtering with my perfed screen and single center speaker from sound striking the solid parts of the screen and bouncing back at the sound being emitted by the speaker.

Ever here a "flange" on a guitar? That is a comb filter that is moved up and down in frequency causing the cancellation to move. Of course, that is not subtle. But the effect with my perfed screen was similar .. but subtle .. as I moved my head ever so slightly.

Jeff
post #37070 of 70896
Quote:
Originally Posted by IceTBC View Post

I wasn't even aware of what comb filtering was so I googled it. I found this one link explaining it and also saying it wasn't anything to get worried about since essentially your brain/ears compensated for it. http://forum.ecoustics.com/bbs/messa...79/572305.html He also cited Floyd E. Toole as verifying this in his book.

I want to say I'm NOT an expert nor did I have any prior knowledge really on comb filtering. But it's interesting his claim that this shouldn't be a factor in what you "hear" once it's filtered by your brain.

Interesting article. How would two speakers, one above and one below a screen, be any different from two speakers in a stereo system, playing a mono source? I don't recall in my old stereo days that this was ever any sort of problem. If the listener is equidistant from the two speakers, it always sounded fine to me. It wouldn't be hard to make the MLP equidistant from the two speakers, one above and one below the screen, if one really wanted to I guess.

Kind Regards,

Keith
post #37071 of 70896
Quote:
Originally Posted by pepar View Post

I can't speak for Chris, but initially there was some confusion over the "X-factors" and how XT 32 lined up against the SVS AS-EQ1 and Audyssey Subwoofer Equalizer.

I have read that they have no plans to upgrade the Sound Equalizer ... maybe he was thinking about that unit ... ?

Jeff

Maybe there was initially some confusion earlier last year, but this was November when I asked the question.

As you can see from the quote of my original message I sent, I clearly stated the Subwoofer EQ.

It may just have been an honest mistake, but it cost me a lot of money, as well as seriously limiting my future options.
post #37072 of 70896
Quote:
Originally Posted by kbarnes701 View Post

How would two speakers, one above and one below a screen, be any different from two speakers in a stereo system, playing a mono source?

All listeners remain the same distance (hopefully equidistant) from both speakers when vertically arranged, allowing the phantom image to stay at the centre of the soundstage with minimal tonal changes for off-axis listeners. With two horizontally arranged speakers, some listeners will be closer to one speaker than the other. Try playing pink noise through your front L/R speakers and swing your head from side to side; you should hear tonal changes (and, of course, the centre image moving as you do).
post #37073 of 70896
Quote:
Originally Posted by mjf_uk View Post

Maybe there was initially some confusion earlier last year, but this was November when I asked the question.

As you can see from the quote of my original message I sent, I clearly stated the Subwoofer EQ.

It may just have been an honest mistake, but it cost me a lot of money, as well as seriously limiting my future options.


He most likely confused it with the Sound Equalizer.It will not be getting any future software updates,since it is being discontinued when available stock runs out.Only the Sound Equalizer PRO(same product as the unbalanced and balanced,but only available for broadcast and studio users)will be continued to be supported.
post #37074 of 70896
Quote:
Originally Posted by StevenLansing View Post

He most likely confused it with the Sound Equalizer.It will not be getting any future software updates,since it is being discontinued when available stock runs out.Only the Sound Equalizer PRO(same product as the unbalanced and balanced,but only available for broadcast and studio users)will be continued to be supported.

But that really is no excuse when I clearly stated "Subwoofer EQ".
post #37075 of 70896
Quote:
Originally Posted by millerwill View Post

Using two center speakers, one below the screen and one above--the first angled up and the latter angled down--would probably do an excellent job, but would be pretty cumbersome.

I'm surprised that LarryChanin hasn't chimed in on this issue, considering that this is exactly his setup: http://mysite.verizon.net/res8ycu4/index.html

He's also posted a lot about this setup and comb-filtering in this thread but that was a long time ago. He's obviously done a lot of research on this.

Mark
post #37076 of 70896
Quote:
Originally Posted by audioguy View Post

The majority of the time I am in my theater, I am listening to music. And no one else is there.

I have calibrated my current Integra 80.2 with Audyssey Pro per the instructions on the Audyssey web site (I used 12 positions) and it sounds very very good (or maybe excellent).

Since it is just me most of the time and sitting in the MLP, would I hear or be able to measure a difference if I did an additional 12 or 20 or ??? measurements at the MLP. The current 12 positions only includes one at the MLP.

It would not be a lot of work to do so but if someone else has done it and found no difference, then I might not try it.

I have more or less the same situation. I used to do up to 28 mic positions with MultEQ Pro but I could never really hear much difference between that and around 15 positions. In fact, I would think there's even a danger that some of the mic positions would not be ideal and would, therefore, compromise the process.

At some point, I vaguely recall that Chris mentioned that the # of mic positions are obviously governed by the law of diminishing returns and that around 15 positions are more than sufficient for most rooms. Therefore, I do 15 positions only.

Mark
post #37077 of 70896
Quote:
Originally Posted by streetsmart88 View Post

I have more or less the same situation. I used to do up to 28 mic positions with MultEQ Pro but I could never really hear much difference between that and around 15 positions. In fact, I would think there's even a danger that some of the mic positions would not be ideal and would, therefore, compromise the process.

At some point, I vaguely recall that Chris mentioned that the # of mic positions are obviously governed by the law of diminishing returns and that around 15 positions are more than sufficient for most rooms. Therefore, I do 15 positions only.

Mark

I posted this here hoping Chris would chime in. I may post on the Audyssey web site. The real question is does Audyssey weight the measurements in any way that would assist in getting a better acoustic response at the MLP if upi did more measurement at that location.
post #37078 of 70896
Quote:
Originally Posted by asrikant View Post

Tom can you tell where you bought this speaker stand? I am lookgin for something like this for my center channle and would very much appreciate if you could link that website here.

Thanks

Sri


Hello Sri,

I was afraid someone might ask that question.

Right after posting, I went to see if there was manufacturer identification on the stand...and there was nothing anywhere on the item. I bought it at an Asheville audio store about 12-15 years ago---the place was called SOUND ONE. Some years ago it changed locations but remained in town. However, the last time I checked that location, there was no advertising sign and the building appeared vacant.

I just did a search under the SOUND ONE name and may have turned up another location in the general area. I noticed one result which even mentioned the owner's name so there may be hope of contacting him about the source of the speaker stand that I bought from him so long ago. Whether he still sells that line of stands (or even remembers them), I really can't say. If I'm able to find out anything more, I'll send you a PM with the info.

I hope I can turn up some helpful information, because that particular speaker stand design has worked well for me over the years and continues to do so.


Tom
post #37079 of 70896
Quote:
Originally Posted by mjf_uk View Post

But that really is no excuse when I clearly stated "Subwoofer EQ".

Just a possible explanation for the confusion,like pepar pointed out,since obviously the SubEQ has been updated to 512x resolution and the SEQ hasn't and won't be updated.
post #37080 of 70896
Quote:
Originally Posted by StevenLansing View Post

Just a possible explanation for the confusion,like pepar pointed out,since obviously the SubEQ has been updated to 512x resolution and the SEQ hasn't and won't be updated.

But as I said, I clearly stated "Subwoofer EQ".
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