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The best Audyssey test... single mic test

35K views 166 replies 17 participants last post by  Wayne A. Pflughaupt 
#1 ·
So far...

a single test... with me at the MLP... with the audyssey mic placed on top my head... (yes, like a stupid little horn coming out the top of my head)...

has produced the best results for me. I find the results to be perfect. It's when you add more than that single test I hate the results.

Of course... this is no sub. I did this for music since in direct mode the SVS Ultras are too much bass. 1/3 smoothing for ease of seeing the "curve" change.
 

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#2 · (Edited)
Talley, what mic are you using for your REW measurement? something is off with what your getting for results. My understanding is if you have readings above 10kHz that hot your ears must be bleeding. Normally they should roll off the higher you get.
EDIT: the term roll off is not the correct word to use but its more a slope down about 10 or so db
 
#4 ·
ya sorry, not sure how to change the color yet, haven't seen that option. the color that shows the big bloat in the low end where the bass is 10+ higher than the rest is the before... audyssey was able to tame the low end back a bit to where it sounds alot better.

The response mainly. Imaging is better too but not as much as the response. Before the bass was boomy/bloated type of thing and now it's very articulate and accurate. Thats my impression at least.
 
#5 ·
Thanks for the info. I was interested because AudiocRaver has indicated that minimizing the number and spacing of mic locations results in improved imaging, compared to spreading them all over the room. His most recent evaluation used a single location and couldn't tell a difference in imaging with or without Audyssey or Dirac (you've seen it, I've seen your posts on the thread).

I’ve never done it, but it looks like the trace colors can be changed in Preferences window, “View” tab.

Regards,
Wayne
 
#6 ·
Thanks for the info. I was interested because AudiocRaver has indicated that minimizing the number and spacing of mic locations results in improved imaging, compared to spreading them all over the room. His most recent evaluation used a single location and couldn't tell a difference in imaging with or without Audyssey or Dirac....
I have an XMC-1 with Dirac, but only a single LP in my small HT room . In trying to keep with the user manual, I spread my initial mic positions over the whole chair. The result was not pretty--congested and confused imaging, glaring mid-range, anemic bass. I started tightening up the pattern during the next three tries thinking that data points on the plane of the armrest or close to the seat cushion were irrelevant.

Sure enough, the sound field gelled when I shrunk the mic pattern down in close proximity to an imaginary head at the LP. Images came into focus, dialog improved immensely, and rear surround effects now played a role. In a nutshell, I felt much more immersed in the movie experience. Not a testimonial to single-mic placement, but I'd wager extrapolation would take SQ to the next level.
 
#9 ·
Audyssey themselves suggest a 1' - 2' max spacing for a focused sweetspot. I'm always clustering as many measurements as i can within a 1'6" radius "disc" at ear height, with the tightest grouping around the ears average position. The most important measurement is the very first one, this must be accurately centered for best focus. I've very rarely got a problem with focus or imaging with this method. A silent room (no AC, computers or people) and good mic stand is essential and cheap.
 
#10 ·
I've noticed in the manual of the Marantz AV7702 the mic positions for Audyssey are really close together vs. in the 8801 they are spread out much more, are they now finding out this produces better results?

What do you do if you have a larger room and want the imaging and performance for a larger area? Do you still suggest using the close mic positions/only 1 mic position?
 
#12 ·
What do you do if you have a larger room and want the imaging and performance for a larger area?
It should be a given that imaging over a wide area is impossible to achieve anyway, due to basic physics, even with no room correction. As Wayne’s work has shown (if I understand it correctly), improved frequency response can be realized over a wide area with DRC, but the penalty is usually bad imaging at the main LP.

Regards,
Wayne
 
#11 ·
A few thoughts:

The single mic point cal method will be favored more by soundstage & imaging (SS&I) perfection chasers. A small sweet spot is a given.

Many will be satisfied with somewhat less focus and will enjoy the greater flexibility of a bigger sweet spot, calling for a more spread-out multi-point mic pattern.

It is simply a matter of available options/tradeoffs and personal preference.

Room size does not seem to be a significant factor, other than allowing the opportunity for SS&I to be much more diffused by using an even more spread out mic pattern.

The Denon AVR-X5200 on-screen instructions for Audyssey setup say to keep all mic positions within 2 feet of the critical #1 mic position. Do not know if this is part of a trend or not, or what other manufacturers are saying.

"What manufacturers suggest" gives an interesting starting point relative to this subject, but in my opinion can be far from definitive. "SS&I" and its creation, not being directly measurable, is a creature that few manufacturers seem to be willing to address directly. Understandably so.
 
#13 ·
Any thoughts on my original question guys? the graph Talley posted shows the highs flat out to 20kHz it is my understanding that thats going to be very harsh on the ears particularly at those levels at the listening position? Should there not be gradual slope down from about 10kHz
 
#15 ·
woa woa woa....

everyone here has always said that you want a flat response and not a "perceived flat response" which would be more of a slope down since we perceive lower frequencies as being lower and the higher as being louder.

My graph above is pushing a more than radical 35° of toe on the Ultras. Even Sonnie told me not to toe these much as they will become brighter.

My verdict is I have them toed in just a bit much. I really like how focused the vocals are right now but I lost a bit of SS&I compared to when I had them at 20° I'm gonna push them back to around 27-28° and see if thats more of a middle ground.

Toe'd in they are brighter... but the "space" of the recording really comes out you get a very good ambience with a less far left/right imaging. The sound stage shrunk but the ambience grew. I like the ambience and the vocals are awesome.

I'll push them back some and retest. Are they harsh?... no. are they bright?... simbilance is vibrant is how I would describe it.

The low end is nice. I wish I could put a more of a curve on it but audyssey won't allow that. I can bump the sub up but it looks like a plateau rising from 80hz down.
 
#17 ·
and by my looking it's down about 7db from 800hz anyway at 20k. it does move down. You can see it easier when you apply more smoothing

I've attached the file so you can look at it.
 

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#19 ·
I wouldn't complain about your room response. Its a nice graph. I just know that in my room if I have the highs that high its too much and becomes tiring at or near reference level . I have about a 5db gradual drop starting at 12kHz out to 20kHz. My EVs have an attenuation control in 3db steps on the highs.
 
#20 ·
Gotcha. Ya I've had some audyssey tests come out like that and then sometimes it's flat. I wish it had some more consistency but at the same time this is when I was doing 8 mic positions too.

What I haven't done is a 8 position cluster around a 2' area. I've always spread out over 6' and I DO NOT like the results on that.

I'll try to do a 4-8 mic maybe even tighter around a 16" cube around the head and see if I can get better results.

Will try tonight and post up tomorrow.
 
#21 ·
if I remember right your seating position is against the rear wall right? thats going to mess with readings no matter what you do because of reflection. Remember your ears are not dead center, and you have two of them so taking only one reading is not going to be ideal because even moving your head will take it out of the perceived sweet spot.
 
#23 ·
I've never got great results with Audyssey with a wide spread. Also, as Audyssey have noted on many occations, the manuals are written by the manufacturer, even for the Audyssey sections. That's why the recommendations vary a little. Also, Audyssey report the -3dB point of each channel to the processor software and that is why you sometimes get conflicting crossover settings.

Audyssey themselves recommend a relatively tight grouping in a flat plane centered on the main listening position.
 
#29 ·
This is an interesting thread. In my previous 5 years or so with Audyssey in multiple receivers I have always used the full number of measurements but kept them within an 18" diameter circle. Today I replaced a TV and moved my center channel a few inches so thought I'd re-run Audyssey with just the single point (actually 3 measurements without moving the mic). Not sure how to explain it, and I suppose it could be placebo, but it does sound better. In the past it was seemed pretty good but just not quite right. This single position measurement seems to have given me the last little extra I was missing...just not exactly sure what that is. :)
 
#30 ·
I'm just saying... put the mic on top of your head while sitting in the MLP. Do a single test.

and report the results. It's fool proof. Your head, the mic is on top, in the center. Done.

Another point is... it's capturing the reflections off your legs, feet, arms, hands... etc. It's real testing done while your sitting there.

Try it.
 
#31 ·
I'm just saying... put the mic on top of your head while sitting in the MLP. Do a single test. and report the results. It's fool proof. Your head, the mic is on top, in the center. Done. Another point is... it's capturing the reflections off your legs, feet, arms, hands... etc. It's real testing done while your sitting there. Try it.
This does sound interesting, and even makes some sense. My reservation is the mic picking up the creaking of your fingers or any subtle shifting of the hair if the mic moves a little. Just sayin. Maybe there's nothing to that?
 
#33 ·
Talley:

I like your approach, taking the body into account. Now if there was a way to just remove the head and... wait a minute, there could be a downside to that method.

If I understand correctly, your seat back is lower, like shoulder height or below? If so, top of head might work just as well as ear level, because no major dip from the seat back reflection - it can be BIG with a high chair back, 10 dB or more.

Something else you might try:
Use soft blankets over pillows to simulate the body, get the mic to center of head location, at ear level. We have two ears, true, but symmetry is often in your favor. You can measure the three points - center of head, L ear, R ear, and see how different they are. If they ARE very different, then you have a serious LP acoustics problem anyway that needs to be solved, and no mic pattern will make it acceptable.

I applaud your brave experimental spirit. What you are trying goes against conventional wisdom and the way Audyssey has said to do it for years and years, but the goal is different, and it sounds like you have been bitten by the SS&I (soundstage & imaging) bug. Too bad there is NO CURE! hee hee
 
#34 ·
Understood and agree. I want to try the tight pattern but have been busy.

As far as my MLP... I'm 3' off the wall and my ears are 12" above the highest part of the couch. I'm not exactly that close to the rear wall I mean it's not 5+ feet like most have but 3' decent enough WHEN combined with my absorption panel I wouldn't think there would be significant reflections there.
 
#61 ·
Pardon my dumbness but I know little of Audyssey. Are these measurements taken with all speakers running, just the front L/R, or the front L/R one at a time?

And does the system apply EQ to each speaker individually?
It measures each speaker one at a time and applies a separate EQ to each speaker as needed.
In that case I expect this is the source of the problem where imaging is concerned. Back in the mid ‘90s when I moved up to high-end equalizers I learned pretty quickly that applying different filters to the left and right speakers above about 3-400 Hz whacked out imaging. I thought perhaps it was because I only had 1/3-octave equalizers at the time, but in recent years, others here on this Forum have confirmed that even with precise parametric equalization they’ve had the same experiences as well.

What a lot of people don’t know is that equalizers accomplish response changes by introducing phase shift at and around the filter’s center frequency setting. With analog equalizers this is accomplished with capacitors and inductors, and with digital equalizers it’s done with taps on a digital delay line. But the fact is, without phase shift equalizers would not work at all. So basically, equalizers use time domain changes to accomplish frequency domain changes.

So why did the mismatched filters mess with imaging? Because a phase change was introduced to one speaker in a certain frequency range, but not the other. Either speaker played independently would sound identical because frequency response was appropriately matched, but played together you get the phase differences and the resulting dislocalized imaging. This is why I’ve typically recommended for people to use matching filters above ~3-400 Hz for the left and right speakers when performing manual equalizing.

The next issue I see, unfortunately, is the wonders of modern computing power. Before the advent of cheap processing, room analysis and equalization was limited to 1/3-octave resolution from both hardware RTA devices and equalizers. That seems quaint and outdated these days: Chris Kyriakakis claims Audyssey MultEQ XT can introduce hundreds of filters, and MultEQ XT32 thousands, to “make corrections to narrow peaks and dips in response,” in his words.

But is this really necessary? Anyone who’s ever had hands-on use of a good parametric EQ (or possibly even a cheap one) will tell you that filters with tiny bandwidth and gain settings get you nothing audible with a program signal. Has Mr. Kyriakakis spent more time in a computer lab than hands-on with actual hardware in a playback system? As I mentioned years ago in my minimal EQ article, what’s the point of peppering the signal chain with a bunch of inaudible filters?

Audyssey utilizes FIR filters which are designed to address time domain (phase) as well as frequency response issues, but the phase issues the filters address are from the room. Maybe I don’t know enough about EQ filtering (very likely), but filters that address phase generated by the room (which isn’t necessarily all bad, by the way) seem to be of diminished effectiveness if they in turn introduce phase of their own.

Wayne’s research from his excellent Audyssey MultEQ FAQ and Setup Guide has confirmed that multiple spread-out mic locations might give improved frequency response over a broad area, but that imaging suffers as a result. I expect the cause of the poor imaging is that this approach results in drastically mismatched filtering between the left and right channels (someone could probably loop an Audyssey-equipped AVR through REW and confirm this).

Thus Wayne’s recommendation on tight mic spacing when running Audyssey is a step in the right direction: Frequency response isn’t going to change significantly a few inches this way or that, at least above ~500 Hz. As a result, Audyssey probably performs less aggressive equalizing – hopefully only a few dozen filters instead of hundreds or thousands – and the result is filters that better match for the left and right speakers.

But is even this tight mic spacing necessary? Try this little test: Turn off the sub, disconnect the left or right speaker, play a broadband pink noise signal through the remaining one, and move your head a few inches away from, and around, the dead-center position – i.e. places where you might locate the Audyssey mic for a tight measurement pattern. Do you hear any audible change in the way the speaker sounds? Not likely, or if so not enough matter. How ‘bout when you move from the center seat on the sofa to the left or right? Probably the same. (Note, we only use one speaker for this because with both you’d hear a change with a mono pink noise signal once moved off-axis from dead center, due to timing [phase].)

The fact is that measurement mics are more sensitive to subtle location changes than the ear. And thanks to the power of cheap processing, that hypersensitivity can be translated to scary graphs that show visible changes in frequency response that the ears simply ignore. Or to a processor that generates “correction” filters to address problems that aren’t audible (introducing phase in the process). So even with the tight spacing technique, with the mic at locations where you can’t hear a difference yourself, Audyssey most likely is still introducing filtering that is offering no audible benefit – at least some, but probably a lot.

So the single-location approach to Audyssey and similar systems makes perfect sense to me. And the experiences of Wayne in his exhaustive evaluations and Talley’s experiences in this thread seem to bear this out.

I’m not saying here that Audyssey and similar systems are overblown and useless, only that some people’s experiences with them only seems to reinforce the idea that minimal EQ is more effective than hundreds or thousands of filters.

Wayne, for your next test maybe you can compare Audyssey or Dirac to manual equalization with a first-class parametric EQ and see if the former really delivers better results, either with response or imagining. :T

Regards,
Wayne
 
#36 · (Edited)
It measures each speaker one at a time and applies a separate EQ to each speaker as needed. The issue with taking only one reading or multipul readings in one spot is that would then be the only spot in the room that would be the "sweet spot" nothing wrong with doing it that way but if you have more then one listening position this would prove to be less than ideal. Also keep in mind that your ears are not in one position you have about a foot between them plus if you move your head having that tight of a sweet spot would mean that any movement out of that area could result in a big drop in the ideal sound your looking for.
I will also add that a speaker that has that tight a dispercment of its sound to change the imaging by moving a foot one way or the other in my opinion is not very well designed. I would look at room treatment first before focussing on that perfect toe in of the front speakers when using for movies as that will also mean that only the one position in the room will be ideal.

I've done the multipul readings within a couple feet of each other and my sweet spot does not noticeably change no matter where I sit in the front row 3 seats and even in the back row it sound great. Could be the quality of my speakers have a better image or just my room I don't know but doing just the one reading does not give me the best results even for music.
 
#37 ·
Good points Tony. I can only speak for myself, but in my family, I'm the only one who's concerned with the sweet spot, and I'm pretty stationary. That's also not to say the rest of the seats are terrible either though. And if I ever demo for someone, they automatically get my seat. This obviously is not always the case, nor is it probably the status quo. Btw, what IS your hat size?
 
#38 ·
#41 ·
:rofl:
 
#42 ·
Yeah Talley, I've thought about a 12"box size too. I have no real enough complaints to go through it again yet though. 'Cept maybe I could be usin me a nuvva subwoofa! I'm a tinkerer like you, but much is going on in our life right now, I'm gonna love it how it is. For now...
 
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