"Official" Audyssey thread (FAQ in post #1) - Page 1841

Yes, but we also quite often get posts questioning all sorts of things that are quite obvious to many of us. I can hear the bass portion of the sweep so I assume most people can. I certainly found it very easy to hear the difference when I had very small temporary speakers as my Heights, when I was initially experimenting with Heights, and those speakers rolled off at about 120Hz. The Audyssey chirps were very different in those speakers, compared to my main speakers, just as I would accept.  I find it hard to understand that the duration of a sound may render it inaudible. As I just asked Feri - what is the duration where inaudibility occurs?

 

 

 

I do believe the chirps, post-Audyssey, may well sound the same. But that isn't what was under discussion. The issue of blown drivers is just a red herring.

Feri, there is no perception involved wrt to the phrase "Audyssey chirps are supposed to sound identical from every speaker". That is an unequivocal statement of fact and is not open to interpretation. The only reason I picked up on it is because some new users may well read that and then assume that, if their chirps do not sound identical, there must be a problem when that is not necessarily the case.

Which is exactly what I would expect from different speakers in different parts of the room. If one applied Feri's hypothesis to your situation, you have a problem. Do you think you have a problem?

 

Feri, with respect, I guess you missed the part of the post that said the back surrounds sound "very different"?

 

Again with respect, that is not the issue here. That is a red herring you introduced to obfuscate your original assertion that "Audyssey chirps are supposed to sound identical from every speaker."  Of course a speaker with a broken driver will sound different!  You don't need Audyssey chirps to ascertain that.

 

 

 

Your quote is just backing up your second assertion that the Audyssey chirps will sound different if a driver is broken. Nobody is disputing that. The paper does not say that the Audyssey chirps are "supposed to sound identical" and, in fact, they are not and do not in all manner of circumstances.

Edited by kbarnes701 - 7/18/12 at 12:35pm

Feri - this is just more obfuscation. All you have to do is admit that your assertion that the Audyssey chirps are "supposed to sound identical" isn’t actually correct. If a newbie sees your post, and it went unchallenged, he would come to the conclusion that if the chirps didn't sound identical then he must have a problem. It isn't so. You are constructing a syllogism.

Keith, my dear friend,

IMHO, a newbie would first ask how to check if the chirps sound identical or not. OK. I'd suggest to move on. Deal?

We have no way of knowing in advance what a newbie might ask, Feri. He might ask nothing at all and see a post from an authoritative and experienced poster in the Official Audyssey Thread and simply assume that the information is correct - and this may well then cause him to worry that his system or Audyssey is not performing as it should. That is the only reason I chimed in and challenged the assertion. I agree - time enough spent on this and time to move on :)  So yes, deal.

 

+1

 

i certainly DON'T have a problem, but if they all sounded the same, then i guess i would.

Thank you Chris, CTO, Audyssey Laboratories

Great reading material, makes me want to invest in a new AV processor that includes Audyssey, unfortunately the Classé SSP-800 lacks any software to do this

Also I asked this question in an other thread but was wondering about your opinion as well?

What happens when a blu ray movie encoded with 5.1 and 7.1 with DD True HD or DTS Master Audio non-compressed, using bitstream and I apply the Dolby Pro IIx to convert the 5.1 to 7.1 or the DD IIz or DTS NeoX to up-convert 5.1 to 9.1? Does that mean the sound is now compressed and the bit rate lowered and it sounds more like a DVD?
Edited by wse - 7/18/12 at 2:06pm

Answered in the other thread.

 

Quite.

Care to expand on what kinda problem you guess you would have?
Edited by mogorf - 7/18/12 at 3:46pm

Per my first posting, "some content" means Blu-Ray movies, HD programming, and even some non-HD programming. It's really intermittent the level of muffled sounds, but it is consistent..to my ears at least.

I think we are still trying to understand what you are hearing. "Intermittent" and "consistent" seem contradictory. For example, in a Blu-ray movie, is the muffled sound consistent for the whole movie, or does the muffled sound come and go within the same movie?

Yep, I can DEFINITELY hear the difference between chirps from my speakers with an F3 down to the 20's and 30's vs. speakers with an F3 of about 100Hz. I tried a Gallo Strada center and a Goldenear SS50 as form factor centers for a little while (much easier to place for sure), before using an E100 as a center. I could easily hear the missing low end in the chirps from the small centers. The E100's (and now the Focus SE's) would produce a much more powerful WHOP starting from the low end. The small centers only produced the mid to upper end of the chirp.

I concur with just about all of that.

One thing I've noticed as far as the "chirps should sound the same" issue
a) I'm NEVER anywhere near the MLP during calibration
b) since I'm never near the MLP but wayy off to the side outside the boundaries of the LR, the speakers are all pointed at significantly different angles from where I am, which is going to influence what I hear simply due to the off angle sound power response
c) speaker placement affects the sound of the chirps. My Right speaker is a little over 4 feet from the side wall, the Left is way further from a side wall. The Focus SE drivers and crossovers are supposedly matched by Bill Dudleston to within 0.2 db, but the chirps from them sound different where I'm standing during the calibration. The proximity of the Right speaker to the corner causes a stronger bass response from the chirp even though I'm standing to the Left of the Left speaker (and much further from the Right speaker).
d) Room modes can affect the lower end of capable speakers. I moved my front E100's to surround duty (yes, I use direct firing 77" tall floorstanders as surrounds). They play flat in-room (REW measured) down to the low 30's, the Focus SE's play flat down to the low 20's. Some of the speakers seem to excite room modes at particular low frequencies where I stand whilst others do not. The measured REW responses of the speakers is not dissimilar enough to account for the differences in what I hear from where I stand.
e) the mid and upper frequencies sound different from the different speakers based on how they're angled relative to where I stand, and/or points of first reflection relative to where I stand during calibration

That said though, I think I would hear a damaged or non-functioning driver during the chirps.


Max

So can I. In fact, I'd be worried if I couldn't. I’d be amazed if everyone here could not hear the difference too.

 

 

Good post. On a), b), c) and e) we are in similar situations and the only reason I omit d) is because our speakers are so different as to make comparison pointless.

 

~Seems pretty conclusive to me that i) the chirps do NOT all have to sound identical and ii) that they may not is not an indication of something being wrong.

i would if i did (have a problem), but i don't.

The duration below which some untrained listeners fail to notice it.

Jeff

Hmmmm :)  Seems to me if a sound is loud enough to be within the range we can hear, and in the FR we can hear, then we can hear it - no matter how short the duration of the sound. I am open to conviction if there is some actual scientific evidence that sounds of a [particular short] duration become inaudible, even though fulfilling the other requirements for human audibility.

 

I'd be interested to know what the duration was where inaudibility kicks in - a millisecond, a microsecond, a nanosecond, a picosecond ... what? Then all we need to know is the duration of the Audyssey chirp and the case is settled :)

 

It seems that we have established from the empirical evidence of myself, Max and Gellidius that the Audyssey chirps can and do sound different, speaker to speaker, in various circumstances and that they are not "supposed to sound identical" in order for one to assume that Audyssey and the speakers are working properly. So this would negate the need for the above information, but I'd still be interested to see any evidence supporting the theory that sounds become inaudible when played for less than a specified duration. Clue: I won't be holding my breath

 

 

EDIT: I couldn’t find any information in a brief web search, but I did come across this amazing bit of information: the reaction time for pigments in the human eye to react to light is 200 millionths of of one billionth of one second.  (200 femtoseconds). For context, a femtosecond is to a second what a second is to about 31.7 million years. The way our bodies work never ceases to amaze me. If our eyes react to light in this way, then it would not surprise me that our ears react to sound similarly.

Edited by kbarnes701 - 7/19/12 at 6:32am

Perhaps the term "inaudible" was misused in this situation where what was really meant was "unrecognizable". People new to audio calibration wouldn't necessarily understand what they're hearing.

That makes far more sense to me.  Although I’d think that even newcomers would be able to recognise that the Audyssey chirps sound quite different in a speaker with an F3 of 30Hz and one with an F3 of 120Hz!

i have a test CD in which there are pulse signals and tonebursts that last a few ms (milli seconds), and they can all be heard very clearly.

Denon Audio Technical CD-1984.

Good point. I have not been using all the precision available to me as an American Anglophile. I am going with "not discernible" which, I think, has a element of not understanding what they are hearing.

Jeff

Is there a sweep that goes from under 20Hz to over 20KHz in a few milliseconds?

I think Jeff was speaking theoretically. It is possible to rerun the chirps after autosetup. It is not possible to rerun the chirps and have the corrections applied in the previous autosetup "in the loop." Audyssey ignores all settings when it runs its chirps.

WRT differences at the low end, I THINK I've heard different bass extension in teh chirps among various speakers, although a speaker with a significantly different midrange profile (I once used a JBL LSR25P as a center with Magnepan L&R) is easy to detect. But if the chirp runs at 75 dB, according to the ISO equal loudness curves, 100 Hz sounds about as loud as 60 dB in the midrange - -still audible, in the range of normal speect - - and 50 Hz sounds like 40 dB in the midrange (getting perilously close to what is sometimes the noise floor in my room, depending on time of day, etc.

@ Pepar:

 

It does not.

 

What it does have is a sweep that goes from 5Hz to 22.05kHz at -15 dB in 60 seconds; quite slow.

I think you got that nailed Jeff!! Let's put it this way: originally Audyssey chirps were not made for "human consumption". I seriously doubt anyone can detect the exact -3 dB point precisely in Hz of any speaker just by simply listening to the chirps. Our ears are not frequency meters, while owing to their rapid duration the chirps were really meant to work within the range of the test mic, yet out of the detectable range of our senses (ears + brain together). Our ears have nothing to do during auto setup, unless otherwise it would not be called auto setup.

While it is true that our ears are not microphones, they can still listen to and hear the Audyssey chirps during setup and can easily distinguish between different-sounding chirps, as evidenced by Gellidius, Max and myself, for whom the chirps are NOT all identical, and for very good reasons. We don't need to detect the "exact -3dB point" - why do you think we do? But what we can (easily) detect is that the chirps sound different when pinging speakers that have very different F3 characteristics - and it does not mean that the setup is somehow flawed or that there is something wrong, or that our speakers have broken drivers.

 

I will not let you get in by the back door on this one, Feri. :)  The Audyssey chirps are NOT supposed to all sound identical in each speaker. They MIGHT do, of course, but no significant deductions can be made if they do not - especially the deduction that something is wrong.

Audyssey chirp in M4R file format, i.e. an iPhone ringtone. Believe me, you will never miss this ring or get it confused with any of the other cellphones that may ring around you. And nobody will root for their phone either when yours rings. They *will* all have that "WTF?" look on their faces. Of course, among the Audyssey cognoscenti, you will be revered.

Jeff