"Official" Audyssey thread (FAQ in post #1) - Page 1921

Originally Posted by lirong 

I wanted to clarify something.

I know that if I run Audyssey and get a subwoofer setting of -12dB Im supposed to lower the volume knob and run Aud again.

Do I need to re-run all 8 steps on my Audyssey at the new sub setting or can I just run the first step, hit measure, and as long as the dB comes out OK then Exit Audyssey after that first step?

Originally Posted by fjames 


I didn't take it like you seem to have at all. It's interesting that he says improving the room also improves the MLP. Good. Didn't see anything about mic location except where he uses "seat" as description of mic placement.

What he's talking about is the logic of the system, using multiple mic placements to arrive at a single solution. So, you routinely have multiple listeners, you spread out the mics. You routinely don't, then you tighten them up. The system in either case gets several inputs which it goes fuzzy on.

The article was written at the very beginning of Audyssey as we know it, then edited a few years later. An interesting historical document, and worth the read, but hardly a definitive piece on how to do it.

Originally Posted by porschedrifter 

Read the guide, but not seeing what the optimal distance is for 2eq mic locations. Do I want the 2nd and 3rd to be just outside the listeners (outside) ear or dead center of the head? What is the optimal min and max distance away from the 1st mic position for 2nd and 3rd as well?

Originally Posted by AV_mike 

You will need to do a full Audyssey setup once you have the sub setup correctly, but to get the sub level right just run a minimum position setup and check the levels that get set - then do the full setup once.

Originally Posted by kbarnes701 


He was answering the question "why not have two different settings - one for multiple listeners and one for a single listener?". The answer was that there's no point because when you measure for multiple listeners it also gives the best result for a single listener. IOW, follow their advice, which has not changed since Audyssey was launched, that the best practice is to measure multiple locations in the room, and not cluster around the MLP if there is only one listener. Doesn’t seem to be any room for interpretation there.

Originally Posted by fjames 

I didn't take it like you seem to have at all. It's interesting that he says improving the room also improves the MLP. Good. Didn't see anything about mic location except where he uses "seat" as description of mic placement.
What he's talking about is the logic of the system, using multiple mic placements to arrive at a single solution. So, you routinely have multiple listeners, you spread out the mics. You routinely don't, then you tighten them up. The system in either case gets several inputs which it goes fuzzy on.
The article was written at the very beginning of Audyssey as we know it, then edited a few years later. An interesting historical document, and worth the read, but hardly a definitive piece on how to do it.

Originally Posted by kbarnes701 

JD and batpig are the Denon authorities (I am in the Onkyo camp) so take their word rather than mine (and Audyssey's website too TBH). If I have got it wrong in my chart, I will correct it asap - and thanks for pointing it out. JD, batpig???

There's no question that XT32 on its own is better than XT with Pro.

There's even a FAQ for it

a)9.   Which is best - XT plus a Pro Kit, or XT32 on its own?



EDIT:

The FAQ answer does list the 3808, 4308, 4810 and 4310 as being Pro kit installer ready. But not the 3811.

Anyone able to confirm if the 3811 is Pro-ready?

Originally Posted by jostenmeat 

Thank you. I'm blind and didn't realize the second column didn't mean it couldn't have Pro. Your work here with this particular topic is good enough for me, thanks again.
On the other topic of XT/Pro vs XT32, I now sort of remember that a primary complaint with non pro calibrations is the midrange bump (if I'm not mistaken; is that what happens?), whereas this can be dialed out with the Pro version. So tell me if my impression is way off here, but in such a case the XT-Pro IS better than XT32 . . . ?

Originally Posted by pepar 


I did think of you - and all of the others who think they need to tighten up the measurement pattern - when I read that. I doubt that Tomlinson's reply will dissuade anyone though. I think Audyssey caved on it because those who bought into the other research that went into MultEQ didn't buy into that part - and they didn't want to alienate customers.

Forgive me if you had already posted on it, but did you percei
ve an improvement in the MLP by narrowing the pattern?

Jeff

Originally Posted by pepar 

The "midrange compensation" (it's a dip, not a bump) can be de-selected in Pro, but some/many have found that it is preferable to leave it in when ... they cross that bridge. And that includes me who thought "well ... MY speakers won't need that" ... I was very wrong. Five seconds of Chaka Khan made it (painfully) obvious.
Pro/XT is better than XT. XT 32 is better than Pro/XT. Pro/XT 32 is better .

Originally Posted by djbluemax1 

My personal take on it:
Despite what Tom H said about EQ'ing the room vs for a single seat, if you read the way the clustering algorithm works, you understand that the wider the variances between measurements, the more the results will have to be a compromise, whereas the more consistent the measurements, the simpler and more precise the correction will be (for one FR curve).
As with Keith, I personally thought that the narrow cluster did improve the sound at my MLP, but of course, I had no way to quickly a/b the two, so auditory memory comes into play. The other factor at play though is familiarity with Harman's How To Listen program and I thought the narrow cluster sounded smoother. This as it turns out, was borne and confirmed with REW measurements. The narrow cluster showed a smoother, flatter FR with measurements using the REW mic within a 1' circle. Since I don't sway like Stevie Wonder while watching movies, or rock back and forth like a mental patient, I didn't feel a need to take REW measurements outside the 1' circle.
After confirming that a narrow Audyssey pattern produced a flatter FR at my MLP, I proceeded to see what pattern was optimal and how few measurements I could use to produce optimal results. I tried narrowing it down to 3 measurements and at first, tried a triangle with the 1st measurement located where the middle of my head would be.
I wound up with a very simple pattern in my room. 3 measurements, the first being approximately between my ears in my normal seating position, the 2nd taken 9-10" forward of that and the 3rd, 2" back from the 1st, all in a straight line at the same height. In my room, this calibration procedure produces a flatter FR than the wider Audyssey recommended pattern with 8 measurements, when measured with REW at position 1, as well as 6" to the left, right and forward of position 1.
Would I recommend my Audyssey calibration procedure to anyone else? An emphatic "NO, not unless you have measurement equipment to determine the results". For folks without independent measurement capability, stick to the standard recommendations.
For me, I get better results at the MLP 'in my room with my setup' AND, recalibrating for whatever reason (setup changes) is much faster.
Max

Originally Posted by jostenmeat 


Thank you. I'm blind and didn't realize the second column didn't mean it couldn't have Pro. Your work here with this particular topic is good enough for me, thanks again.

On the other topic of XT/Pro vs XT32, I now sort of remember that a primary complaint with non pro calibrations is the midrange bump (if I'm not mistaken; is that what happens?), whereas this can be dialed out with the Pro version. So tell me if my impression is way off here, but in such a case the XT-Pro IS better than XT32 . . . ?

Originally Posted by djbluemax1 

Despite what Tom H said about EQ'ing the room vs for a single seat, if you read the way the clustering algorithm works, you understand that the wider the variances between measurements, the more the results will have to be a compromise, whereas the more consistent the measurements, the simpler and more precise the correction will be (for one FR curve).

As with Keith, I personally thought that the narrow cluster did improve the sound at my MLP, but of course, I had no way to quickly a/b the two, so auditory memory comes into play. The other factor at play though is familiarity with Harman's How To Listen program and I thought the narrow cluster sounded smoother. This as it turns out, was borne and confirmed with REW measurements. The narrow cluster showed a smoother, flatter FR with measurements using the REW mic within a 1' circle. Since I don't sway like Stevie Wonder while watching movies, or rock back and forth like a mental patient, I didn't feel a need to take REW measurements outside the 1' circle.

After confirming that a narrow Audyssey pattern produced a flatter FR at my MLP, I proceeded to see what pattern was optimal and how few measurements I could use to produce optimal results. I tried narrowing it down to 3 measurements and at first, tried a triangle with the 1st measurement located where the middle of my head would be.

I wound up with a very simple pattern in my room. 3 measurements, the first being approximately between my ears in my normal seating position, the 2nd taken 9-10" forward of that and the 3rd, 2" back from the 1st, all in a straight line at the same height. In my room, this calibration procedure produces a flatter FR than the wider Audyssey recommended pattern with 8 measurements, when measured with REW at position 1, as well as 6" to the left, right and forward of position 1.

Would I recommend my Audyssey calibration procedure to anyone else? An emphatic "NO, not unless you have measurement equipment to determine the results". For folks without independent measurement capability, stick to the standard recommendations.

For me, I get better results at the MLP 'in my room with my setup' AND, recalibrating for whatever reason (setup changes) is much faster.


Max

Originally Posted by pepar 

I missed the part where there was one tighter pattern - around the "audiophile's" seat - and another pattern to use if there are multiple listeners. In fact, what I read is exactly the opposite. Otherwise, they'd have gone with two settings ....
Should I go back and read it again? Or can you quote the part that supports your position? I might have missed it ... Or perhaps you read the same thing I did and simply have a different interpretation? Or maybe, in spite of what the inventors say, you simply prefer to do it your way? No problem if that's the case, but don't put YOUR words in THEIR mouths.
Jeff

Originally Posted by fjames 

There are plenty of actual setup recommendations available from the mouth of Chris, and he often tells people to tighten up the mic placement, and he also makes clear that the point is to give Audyssey multiple inputs from various points about the room.

Originally Posted by fjames 

My position is that this is a historical document, not a setup guide. It therefore is open to interpretation, which we both are doing. The difference seems to be that you insist that yours is the only correct one, which is silly.
There are plenty of actual setup recommendations available from the mouth of Chris, and he often tells people to tighten up the mic placement, and he also makes clear that the point is to give Audyssey multiple inputs from various points about the room. Their basic setup guide says to start at the MLP and work outward. It also says to focus on the main listening area.
What I'm saying is if you consider those two points - focus on main listening area, and give Audyssey the variation it needs to do its thing, a reasonable user can see that mic placement could vary between a multiple user setup and s single user setup, and still satisfy the prerequisites of a proper setup.

Originally Posted by pepar 

I did think of you - and all of the others who think they need to tighten up the measurement pattern - when I read that. I doubt that Tomlinson's reply will dissuade anyone though. I think Audyssey caved on it because those who bought into the other research that went into MultEQ didn't buy into that part - and they didn't want to alienate customers.
Forgive me if you had already posted on it, but did you perceive an improvement in the MLP by narrowing the pattern?
Jeff

Chris takes over, "So part 1 was, we knew if you EQ for the single sweet spot then every other position would suffer from much poorer frequency response. (And that was one of the reasons for the bad name 1/3 rd octave equalizers were given.-Tom) Initially Denon and every other potential customer thought 'let's have two modes'. One for a sole listener and one for when you have several listeners in a room. Well, it turns out if you EQ a whole room the audiophile seat gets better. If you take more of the problems of the room into account you're fixing a bigger area than just the audiophile seat so there's no need for two modes."

Chris continues, "The approach other people have taken is to throw DSP at it. There are room correction units on the market that do just that. They can do 8000-tap FIRs and you need 3 DSPs per channel. But if you want to be in a consumer product you have to make some computing decisions. So that was the thinking that went into Audyssey's Dynamic Frequency Allocation.

I then asked "Does it give the same response at each listening location? How is it possible, for instance, if you have a standard D'Apollito-style center channel which is known to have a lobe which points mostly toward the audiophile seat." Chris responds, "By measuring the response at different locations we use a fuzzy-logic based clustering approach which, after computation, makes the sound at the audiophile seat better. The average assigns equal importance to each seat, an importance of 1. Now by applying a weighting factor automatically we use an approach based on pattern recognition. It doesn't have anything to do with what we know about acoustics," Chris stresses. "This is the leap of faith. It is the first application of fuzzy logic that I know of in audio."

"If we were to treat the time domain version of these responses and say which of the criteria are closer to each other as far as pattern similarity, then I find for instance that seats 1, 3 and 5 in the room are "clustered" as far as similarity, seat 2 is by itself and seats 2 and 4 are similarly grouped together."

I interject and ask if the sound the system is reading is mainly direct sound and first order reflections and the answer was "No". "The response that we're taking is quite long. It's 8000 samples over 200 milliseconds. If you look at the time response, it has a pattern. But if the seats have similar problems, they will fall into similar clusters as set up by our pattern recognition method. Where it gets fuzzy is that a particular seat can belong to more than one cluster. In other words, what it says is that based on our theory that seat #2 has 80% of the characteristics of seat #3 but 20% of the characteristics of seat #1. So there are no hard boundaries."

"So now we have six responses which we've clustered into 3 groups. From each response we elect a representative of the cluster. It's not any one (exactly within the cluster), it's one that represents each one in the cluster in the optimal way. That's called a cluster centroid. So now, of the 3 clusters you have, you have 3 representative responses. So you do it again until you finally end up with the "President response" which represents the constituent responses in the optimal way. So the final representative response is the one we take and invert. When we invert we are inverting proportionally and non-linearly."

"Initially Denon and every other potential customer thought 'let's have two modes'. One for a sole listener and one for when you have several listeners in a room. Well, it turns out if you EQ a whole room the audiophile seat gets better. If you take more of the problems of the room into account you're fixing a bigger area than just the audiophile seat so there's no need for two modes."

Originally Posted by pepar 

If you want to disagree with what the "historical document" says because you want to do it differently and you are achieving your desired result, that is fine. You are solid ground. My issue is with you somehow "re-interpreting" TH's statements.

Originally Posted by fjames 

What I'm saying is if you consider those two points - focus on main listening area, and give Audyssey the variation it needs to do its thing, a reasonable user can see that mic placement could vary between a multiple user setup and s single user setup, and still satisfy the prerequisites of a proper setup.

Originally Posted by djbluemax1 

One of the comments in that interview that I found amusing though, was when Tom mentions that there are some things you can't electronically correct "like first reflections". Something that's also confirmed (at least for Audyssey) by independent measurements.


Max

Originally Posted by craig john 

I don't know if I'm one of the "others" you thought about, but I recently re-ran Audyssey and tightened up my mic placements clustered more closely around the primary LP. I posted diagrams of my old and new mic patterns, the resultant FR measurements and my listening impressions here: http://www.avsforum.com/t/1349395/craig-johns-theater/210#post_22428636 I think my "new" mic pattern provides the system with good info about the "space" while prioritizing the primary LP. Reading this part of the interview I think reinforces that my new mic pattern is a viable approach:
If you read Chris' comments about how the clustering works, it seems obvious that clustering around the primary LP will optimize the primary LP more than spreading the measurements out throughout the entire listening area. I can't see how there is anything "wrong" with that.

Craig

Originally Posted by fjames 

What we should be doing is celebrating with wondrous amazement what TH had to go through back in the day with THX compared to what we can do in the privacy of our own homes now. 

Originally Posted by Theresa 

Congratulations on your new subs! I'm certain your elated.

Originally Posted by kbarnes701 

Audyssey and tweakery next....