"Official" Audyssey thread (FAQ in post #1) - Page 3

Btw, Chris did say one more interesting thing. Loudness, as implemented in the past, was based on the wrong psychoacoustic model. The Fletcher-Munson curves are for headphone listening.

http://www.avsforum.com/avs-vb/showt...&&#post8679354

"Got a friend who knows a big importer in Miami area and he said he heard that Denon will officially launch the new model during the next CES in Vegas (Jan' 07) and it'll be 3808. Product availability between Feb-Mar timeframe.

It'll have everything the 2807 has (compared to the 3806) + an improved Audyssey MultEQXT and 3 hdmi inputs as well."

My money is on either the new 3808 or maybe the new Sherwood Newcastle R972.

My only problem with that IS the fact that the 3808 was NOT shown at the CES 07 .. The seperates were but those were A LOT more then I can afford.... I will be thrilled if it is the 3808 but I am skeptical...

I have gone through this thread and the other where Chris (CTO of Audyssey, thread link: "My AVR-3806 Audyssey experience! (measurements inside)" ) answered a whole lot of questions. Improvements by multeq seem to be well recognized by everyone except for bass, which turned them down and it still remains a mystery. I had a few doubts regarding this "bass" concerns. It would be great if Chris himself could comment on these, but looks like he hasn't been active of late

1. This one may sound trivial/ridiculous, but does multeq (by any chance) mess up with standard +10db boost required for LFE? (more details about that are given in this thread: "LFE, subwoofers and interconnects explained")

2. Is the lack of low frequency resolution (possibly due to 512 tap limit) the actual culprit? I am aware however that Audyssey is using some technique to overcome this, named "dynamic frequency allocation" or something, but still wondering... it may not be good enough?

3. Somebody had said in the above mentioned thread that there is some firmware upgrade available for a denon receiver (page #173 ). He specifically mentions that the original firmware "has a problem with EQ below 80 Hz". So, was it the same lack-of-bass problem that so many people have complained about? (or was it a different issue altogether?)

pardon me for any ignorances.

PS: I wasn't able to insert thread links because this is my 1st post So, I have mentioned their names/post number which I thought was the next best option!

My impression was that it is a problem with lower bass in general, not strictly subsonic. I might have gotten it wrong.



Agreed, mixing LFE and other channels is not really Audyssey's job, but what I thought was that there could be a bug in integrating Audyssey into receiver's existing bass management. I thought about LFE boost because some people reported that increasing bass level seems to help (as you just mentioned). Another reasoning is that Chris had suggested a couple of other workarounds related to speaker setting in denon- changing "large" to "small" and "LFE" to "LFE+Mains" and I believe both of which are meant to redirect bass from all channels to subwoofer, in addition to LFE channel. It implies that LFE wasn't loud enough but mixing from other channels was. Does that make sense?

After you run Audyssey Auto EQ any changes you make in speaker size and bass management overrides Audyssey. In most systems after you run Audyssey Auto EQ you should go into speaker setup and change (if necessary) all the speakers small and cross them over at 80Hz. Audyssey usually does not get this part right. There is a separate setting for the LFE xover which should be set to 120Hz. Once you set all your speakers to small, bass management is moot. Everything below the xover goes to the sub and everything above the xover goes to the speakers regardless of the bass management settings.

Nick

No.

Audyssey does not only substantially cut through subsonic content (ie, below 20hz), but will dramatically impact 20-30hz as well. You can read this thread for more information:
http://www.avsforum.com/avs-vb/showt...highlight=3806

Trimming the subwoofer does NOT solve this issue. Audyssey MultiEQ was designed for the average consumer, which generally speaking, will not have subwoofers capable of reference output below 25hz. They have addressed this issue with the PRO version of Audyssey, and they have also paired with subwoofer companies such as SVS to address and provide the benefits of Audyssey down into the low extension realms:
http://www.svsound.com/CES2007/SVS_AudyessyRelease.pdf

My experience is with the stand-alone "Sound EQ" box and so may not apply to those versions built into receivers. I found a loss of bass as seems common, but in looking at the before and after curves, there was a relatively large "bubble" between 30 and 60 Hz (approaching 10 db as I recall) that was flattened. And, of course, that was appropriate. The sub output was put where it should be. But, to get my preferred stronger sub output, I pushed the sub up 3 or 4 db. Now it's up 3-4 db across the board instead of just averaging 3-4 db up (due to the 10 db bubble centered at 45 Hz). I don't know if the bubble was room gain or acoustics associated with an odd-shaped room or my sub, but it's fixed.

In talking to the installer, I gathered that Audyssey is a bit conservative about pushing the sub output up below about 40 Hz. Sub cone excursion in that region is often close to the driver limits and the sub design recognizes that constraint. If Sound EQ pushes the gain up in that region, the driver can fail where it wouldn't otherwise.

I would suspect that this may eventually be addressed by Audyssey, at least in the free-standing Sound EQ, though it will open the door for installers to unknowingly destroy a sub that is not up to the task.

I think it was made clear in several posts, but to be sure, you definitely want to tell Sound EQ which speakers are set large and which are set small and where you will cross over to the sub. Sound EQ will recommend settings, but will accept your chosen settings and optimize the crossover transitions based on them.

Personally, I thought I had a fairly good system before trying MultEQ. The improvement was astounding. My wife is now infrequently bothered by "what did he say?"

I have a situation that I could use help with. I have MultEQ (the free-standing Audyssey product) and I'll soon install a second sub. I can put both subs on one channel or I can allot two channels, one to each sub (and use a single channel for my rear surrounds). MultEQ setup would thus be EQ'ing two subs at the same time or EQ'ing them one at a time. I should probably try it both ways, but am open to suggestions. Has anyone faced this problem?

Thanks.

I once asked that question, using a different outboard EQ, but never got an answer.

No matter the answer, room acoustics has so many variables that the best advice is probably to try it and pick what sounds best, even if one way is theoretically better.

Giving up a rear channel is another wrinkle, though.

Noah,

I've thought about this more. If I understand how the Sound EQ works (grouping readings from different mic positions and adding or removing gain to balance peaks and valleys at each frequency), then two subs should each have their own equalization. My reasoning is that with two sources on one channel, one source may not be contributing to a problem but will be adjusted anyway and this may not provide the desired improvement. For instance, in the worst case, one sub provides flat SPL across the listening area and the other has peaks and valleys. Sound EQ will, I think, try to even out the peaks and valleys, say, from +8 db and -2 db to +5 db and -5 db by reducing gain by 3 db. The flat source that is not contributing to the peak/valley problem will be adjusted needlessly and will bring the levels down to +2 db and -8 db. Hence Sound EQ will get more correction than it wanted in this example. If the two subs could be EQ's separately, the flat one would not be changed and the other one would be changed to correct the peak/valley unbalance. I'm thinking only SPL here. The phase/time correction seems likely to also benefit from independent correction, though if the two subs are equidistant from the center of the listening area and from the far walls and such, phase/time should be less of a problem. Or maybe not.

Then the problem is getting Sound EQ to recognize two subs and build a smooth transition to one or the other or, ideally, both. Since multiple subs are allowed, presumably this is taken care of.

My installer is a techie but may not want to tackle this. But, maybe the need if not already addressed, will get back to Audyssey. I think there are a lot of us out there with two subs.

I would sacrifice one rear channel and be limited to a 6.1 system instead of 7.1. There aren't that many 7.1 DVDs out in my experience.

I hope this makes sense. I'm an engineer, but this stuff is far from my field.

I use Audyssey with my Denon 3806, and I like what it does mostly. But nothing beats room treatments to solve acoustic issues. My personal experience is with bass traps and all I can say is "wow".

Nick

I think I'm pretty lucky room treatment-wise. The Sound EQ "before" plots didn't show anything really troublesome and predicted results were quite flat. That may be because of a large mid-room fireplace with very course and deep stone that probably gobbles up a lot sound energy. Also, myriad hallways and alcoves and such none of which seem to add a really bad mode and help break up the box shape. For instance, diagonally opposite my corner subwoofer is a large open hallway into a large bedroom that probably minimizes the usual corner-to-corner sub modes. But, it would be interesting to see what a pro would do with the room and then top it off with a fresh Sound EQ tuneup.

"For instance, in the worst case, one sub provides flat SPL across the listening area and the other has peaks and valleys. "

Each sub may have the response you mentioned, but what happens when you combine them? I believe they interact and have different responses when used together.

From what I've read, I don't believe they just sum, although now that I say that, it doesn't sound right. I believe subs are linear systems, so superposition should apply.

"There aren't that many 7.1 DVDs out in my experience."

If one sub had a null, it would be *better* to fix it with the other sub to avoid overdriving.

Logic 7 and DPLIIx will generate 7 ch from any 2- or 5-ch source.

I think I'm pretty lucky room treatment-wise. The Sound EQ "before" plots didn't show anything really troublesome and predicted results were quite flat. There are multiple room features that I think contribute to that result. But, it would be interesting to see what a pro would do with the room and then top it off with a fresh Sound EQ tuneup.

"Each sub may have the response you mentioned, but what happens when you combine them? I believe they interact and have different responses when used together.

From what I've read, I don't believe they just sum, although now that I say that, it doesn't sound right. I believe subs are linear systems, so superposition should apply."

Noah,

You are absolutely correct. I went off half cocked. One can't separate phase and magnitude (out-of-phase signals produce a null). Etc. It's a lot more complex than that. Just how complex is apparent here:
http://www.harman.com/wp/pdf/Loudspeakers&RoomsPt3.pdf

I suspect that Sound EQ can do a decent EQ with two subs on one EQ channel or with each sub on its own channel. In either case the EQ feeds a known signal, measures the results, and designs a filter to correct any problems. I lean toward the second option though, partly based on this example:
http://www.audioholics.com/productre...eyMultEQp1.php

and partly because with two different sub locations, I think one channel per sub will break the task down and effectively apply more processing power. I.e., if each sub can be individually corrected to provide flat response and the proper phase, then the two subs should look the same from the seating area and thus provide only an SPL increase when the second one is cut in.

The importance of two subs being equidistant from the listening area is stressed here (last few paragraphs on page 3):
http://www.audioholics.com/techtips/...ProPrimer3.php

Clearly Sound EQ can't correct the huge time error from an out-of-phase sub at 20 Hz so it's important that both subs be not only equidistant but about the same distance as the mains from the listeners. Given a reasonable starting condition, I suspect Sound EQ can achieve near perfection.

Interestingly, the Harmon article on page 22 presents a situation where two subs is problematic and removing one (or stacking it on top of the other one) is better. Of course, the author didn't have the benefit of Sound EQ.

I must admit I am not at all familiar with the sonic dynamics addressed by this system. But the audyssey website claims one feature I am very intrested in- compensating for a center channel placed behind your screen. Has anyone had experience with this? Is there a noticable difference in sound and dialogue clarity? It seems like a much more cost effective treatment than rigging an AT screen

Thanks!

They mean it will EQ for an AT screen, not that you don't have to use one.

aaahh makes sense thanks noah

I thought a couple of minor clarifications to my Audyssey Sound Equalizer article might help here

1. You can put two subs on a single channel of the ASEq and ask the Equlizer to derive a single amplitude and phase correction algorithm only if two parameters are met simultaneously>
a. The subs should be placed symmetrically within the room (i.e. at the two 1/3rd distance points across the front wall or to the left and right sides of the listening area and 1/3rd back into a symmetrical rectangular room)
b) Note that in either of these two examples each subwoofer's distance to the first position should be identical. Note also that if you don't have a sealed rectangular room but are listening instead in a rectangular room with, for instance, a large arched open entry the symmetry will be lost.

2 If you do have asymmetry in the placement of two subwoofers than you have no choice but to assign a separate channel on the ASEq to each sub. Again refer to my article. The ASEq MultEQ Pro algorithms solve for both amplitude and phase relative to the prime, (first) listening position.

3. My two subs are different distances from my prime (first) listening position. I average the two distances and input that average in the Denon 3806 which I'm using as a pre-pro. Remember, bass wave lengths are very, very long and the speed of sound is 1130 ft/sec so once you've got the two bass frequency responses flattened and the two phases relative to the prime (first) listening position correct then the slight differences in distance from each sub to the prime (first) listening position are all but irrelevant.

4. Two identical subs positioned exactly symmetrically will produce +6dB over a single sub in the same room.

Hope this helps....

Patrick Hart

"Clearly Sound EQ can't correct the huge time error from an out-of-phase sub at 20 Hz so it's important that both subs be not only equidistant but about the same distance as the mains from the listeners."

Didn't notice your last response til now.

As Patrick notes in 3., a lot of distance at low freq doesn't amount to match phase shift.

Even 90 deg of phase shift only slightly reduces the summed amplitude.

Actually I wish Audyssey would allow a fixed phase shift ton be applied like Lexicon does with its Bass Enhance function.

I had a DC1 and it gave a freer, opener sound and less of that pressure on the ears feeling.

It makes sense to me; you can think of it as bass reverb via time delay, mimicing what a large

Help!
I need a new receiver and am looking at the Denon 2807. I've been trying to read all the posts in this thread ... whew.

I have Definitive Tech BP7004 speakers. The upper range frequency can be quite bright in nature, unrelenting and can be almost unlistenable, some probably is due to the bright recording.
Will the Audyssey EQ in the 2807 helps to correct this?

My room is 14' X 18.5' hardwood with a rug and windows running across one side. I'm learning slowly about room treatment but bot sure what I need.

Any help I would really appreciated.

Thanks

This might help a little. I have Klipsch RF speakers. I bought them in spite of their reputation for bright and even raw highs. They indeed were initially intolerable for CD listening and not bad for other sources. This was in spite of a 10500 cubic foot room that should have little problem with highs. The reason for the CD problem turned out to be a very low quality D/A in my Sony Carousel CD player. When I got a new pre/pro that could take digital out from the CD player and do the D/A in a quality manner, the harshness problem with CDs disappeared. The Klipsch had been accurately delivering artifacts generated by the low quality D/A. I wouldn't even call the Klipsh speakers bright now, again due probably the the large room in which I get very little reflected highs.

But, there's more. When I got an Audyssey Sound EQ with multiple high-end roll-off options and heard the difference between them, there was no question that the Audyssey could tailor the high end to my preference and/or to compensate for room characteristics. In my listening room (my "great room") the "before" plots were absolutely flat to 20kHz. They now roll-off according to the #1 roll-off option in the Sound EQ. I now have highs that simply sparkle. Accurate and exhilarating. Pleasing, not annoying.

In a smaller room I would probably be using the Audyssey #2 roll-off or even another option that I don't recall the name of, but rolls off even more quickly.

I do not know the high-end roll-off options available in the Denon 2807, but if there are several in addition to "flat", you will likely be very happy with one of them.

Hope this helps.

hclarkx,
Thanks very much for the response. I don't know what "roll off" option is available on the 2807. Can anyone confirm for me? Maybe I should post this question at the 2807 owner's thread.

I don't know what D/A I have but I'm curently using the Toshiba HD DVD player thru the 6 channels analog out and it sounds pretty good, much better than my other dvd player.

AFAIK the receivers don't have any HF rolloff options.

Thanks noah.

I'm reading the owner's manual and there's an option "flat" ...it says soemthing about all channel music listening...but not sure what it does as far as roll off is concerned.

I have a Denon 4306, it's Audyssey options are:

Audyssey: Incorporates a HF roll-off, can be used to tame bright movie soundtracks, or a combination of bright room/speakers
Flat: No HF roll-off
Front: Tailors the center and surround speakers to have the same characteristics as the front L/R speakers
Manual: Provides a graphic eq, when you use this option you lose Audyssey's benefits in exchange for being able to adjust the EQ independently for each speaker
Off: No Audyssey or Graphic Eq alterations to the signal

I believe that the other Denon receivers have a similar implementation of Audyssey selections.

The 2807 has the "Audyssey "option as well as the other you listed here. But I don't see any description like that of what you're specifying here .... I can't find the term roll off in the user manual anywhere.

NM I found it..it says that it does have a slight roll-off...but I can't find the text above that you found...
"Audyssey: Incorporates a HF roll-off, can be used to tame bright movie soundtracks, or a combination of bright room/speakers"

I tried accessing the 2807 manual at Denon's website, but I was receiving errors, looks like they are having some problems at the current time.

I can tell you that on the 4306, 3806, and some of the higher models, Audyssey is basically an equalizer with four settings, the settings are:
Audyssey
Flat
Front
Manual

Each setting acts as I previously described, the way to access a particular setting is to depress the Audyssey button, and it will toggle through each setting. I'd be surprised if Denon didn't have similar functionality on all of their receivers which incorporate Audyssey. If I can get to the 2807 manual I will take a look and let you know whether or not it looks like the 2807 has a similar or different Audyssey implementation.