"Official" Audyssey thread (FAQ in post #1) - Page 992

How much can nulls be boosted? Getting confused here.

9 dB is the limit we have imposed.

The best use of this spread sheet is to tell you the distribution of modes caused by the dimensions of your room. A room with "good" dimensions would produce modes in which the peaks and dips are evenly distributed. There is no such thing as a room without modes. The trick is to play with the dimensions so that you can spread out the problems spatially. Obviously this is only really useful if you haven't built your room yet...

For example, try making a room that is a cube--all dimensions equal. Now, all the peaks and dips fall at exactly the same frequencies. This is the nightmare scenario: the peaks and dips caused by all three pairs of parallel surfaces in the room are in the same locations

From the looks of the graphs on the SVS AS-EQ1 site most nulls are less than that. Is it fair to say most nulls in a typical enclosed rectangular HTcan be substantially fixed?

I suspect that might be more apparent than real and due to smoothing.

Any idea what's the smoothing applied to those graphs?

Nope.

Yes, very true. The smoothing is 1/6th octave in those graphs.

Simon, happy to hear that your hardware problem was resolved.


Whoa! There's some splanin' to do here...

Every product with Audyssey is certified to run a certain version of MultEQ. They range from the basic 2EQ to the most advanced MultEQ XT (and soon MultEQ XT32). If a product has a certain logo then it runs the same Audyssey software as every other product with that Audyssey logo.

If a manufacturer decides not to apply MultEQ to certain sampling rates (e.g. silly 192 kHz and above ), that doesn't mean that MultEQ at normal sampling rates is limited. They are just making a wise use of resources

So, no, your NAD does not "suffer" from lack of processing power. How are you measuring the headroom and finding it reduced?

Hi Chris! It is always so nice to pop into this thread and see that you are still so dedicted to the Audyssey users!

I know the Onko NR-1007 calibrates dual subs differently than the NR-807. I am not specifically referring to the fact that the 807 has regular Mult-Eq, and the 1007 has XT. I am referring to the 1007 applying filters to EACH sub vs. the 807 applying filters to both subs as a whole.

My question is, how does the bass management of the Onkyo NR1007 compare to that of the AS-EQ1?? Thank you in advance!!

Hi,
First a small clarification: bass management refers to the process of redirecting bass from the satellite speakers to the subwoofers. Audyssey has nothing to do with this.

I understand that you are referring to the way subwoofers are equalized by Audyssey. In all products with two subwoofer outputs, Audyssey has always pinged each subwoofer separately when it is allowed to do so by the AVR maker. When it does, it measures the delay and level for each sub and corrects for any differences between the subs and the main speakers. Also, it creates a separate MultEQ correction filter for each sub separately. In some products, the manufacturer simply provides a y-corded output on two connectors and so we are not able to do individual correction.

In the AS-EQ1 we implemented something more advanced. Audyssey first pings the two subs and measures distance and level. Then it applies the distance and level corrections to make the two subs sum as "one" acoustically. After that it pings them together to determine the room correction filter for the acoustical sum. This achieves better blending between the two subs than the individual correction filters.

From the increase in the volume required to listen to what i would call a desirable level. I may be using the wrong term here but what I mean by headroom is for example if I calibrated with the inbuilt Audyssey XT and watch say Hulk in DTS-HD Master Audio I find having it no higher than -12/-13 on the NAD is about the loudest I can handle. After calibrating with Pro I found I have to have it at least -8/-6 on the NAD. I'm finding that every True-HD BD disc I have always is lower in volume than DTS-HD Master Audio and last night watched Kung-Fu Panda and I had to have the volume at -5. At this volume the bass is insane (calibrated with SVS AS-EQ unit) but the overall soundstage doesn't seem to be as dynamic. I mean that's 5db below reference which doesn't leave much more on the dial before one goes beyond the reference point and I've read many post where people don't get anywhere near reference on their systems. I guess that's what I mean by headroom which is the difference b/w what I'm having to set the volume at on the NAD to reaching the reference point. I would think there would be more of a gap between what is a acceptable level and what is rediculous. It's like the NAD is running out of puff. My system is powered by a Krell TAS 5 channel power amp so I have enough power for the speakers. It's strange that there's a difference in the volume settings b/w XT and Pro for the same media,which is why I asked the question about the processing capabilties of the new module card (AM-200). So does Audyssey Pro use more of the resourses in the NAD than XT?

No, the NAD is not running "out of puff". It's a pre-pro and so it just does the decoding. I don't know why there is a difference in level between the built-in MultEQ XT and MultEQ Pro. However, your finding that TrueHD sounds soft is not new. It's a common complaint that our friends at Dolby need to answer. There is a big level difference observed just by watching a movie on BD and switching the audio on the BD player between TrueHD and Dolby Digital.

Also, MultEQ Pro and MultEQ XT use exactly the same resources on the NAD. Identical. The advantage of MultEQ Pro comes in three areas: (1) better microphone; (2) ability to customize curves and save/recall measurements; (3) more measurement positions. The calculations to determine the filters are done on the PC, but the final filters that are downloaded on the pre-pro take up the same resources as the built-in MultEQ XT filters do. It can't be any other way since the internal chip can only run that size filter.

Thanks Chris that's really good to know and has been on my mind for quite some time. Appreciate the time you've taken to set this straight.

Chris,

Are we onto something with staggering some measurement positions away from the "rows and columns" pattern that seems to be a natural extension of the placement and number of seats we have? Some of us have achieved better results by adding "odd" locations.

Jeff

Just ran my first Audyssey calibration on my 4810.
The process went smoothly and produced favorable results with the exception of the much lowered channel levels.
Almost all my channels were set at -6 or -7db.
I checked all the levels with a sound meter and all my channels were only outputting 70db.
Normally I have all my speakers outputting 75db.
Any idea why it did this? Is this typical?
Should I just manually raise all the levels until the speakers are outputting 75db?
The speaker distances and crossover settings were all very much in line.
The Audssey calibration did wonders for taming my subs and now sound powerful and smooth without the boom.

I was under the impression that this room calculator could help locate nulls and avoid that as a mic position thereby prevent over boosting?

When you say "4 rigid walls..." within reason don't most of room have these? Or are you referring to non-enclosed rooms such as those that open into halls or other spaces?

Hi Jeff,
We haven't found any correlation between a specific measurement pattern and better results. That's not to say there isn't one, just that we have not seen it.

My Radio Shack meter, if that's what you are using, consistently measures my main channels 3.5dB low with my pre/pro's test noise. And I don't rely on it at all for sub levels. For that I use the Level Check function of the AS-EQ1 "Sub EQ" software.

Jeff

Nulls of different frequencies will show up pretty much everywhere in the room. They are hard to avoid. It can help find where modes cause overlapping nulls--for example those due to front-back wall and ceiling-floor. But, there is no danger of overboosting because MultEQ limits the max amount of boost it will provide.


I was referring to rooms that open into adjacent rooms or halls. The calculator doesn't account for these situations.

This is the exact same symptom that I had with my 4310. I reran it again and it was better.

I have no idea why this happened.

What test signal are you using to measure? Hopefully it's the internally generated narrowband pink noise and not one from a disc. In several cases, we have seen discs with incorrect dialnorm settings that can cause a 4 dB discrepancy.

Also, what are the settings on your SPL meter? It should be set to C-weighting, Slow and held away from your body so that the tip of the mic is at the same location as the first mic position used for MultEQ.

Thanks, Chris. I was thinking that that might be the case based on your not commenting when we were in the midst of discussing what some of us thought was a .. "breakthrough."

Maybe at this point, we should just have the "add some staggered measurements" on our list of suggestions for people to try when they complain about the bass after it's been determined that it's not just that they didn't know what flat, reference bass is?

Jeff

I'm not sure there is enough evidence to add this to the guide. The guide is already scaring some people into thinking this is a much more complicated process than it needs to be...

Yes, I know. That is why before posting my last post I deleted a long explanation of what I had done and what the changes were in what I had heard.

Can you tell us if your feedback from/experience with Pro installers has pointed to any commonality wrt the measurement patterns that they employ? I am bedeviled by what I heard when I modified the pattern; it was that dramatic.

Jeff

We have collected a great deal of data from more than 1000 rooms and Tom Holman will be presenting the results of the analysis at AES later this year. However, we don't really have any info that shows preferred patterns of installers.

I do just as you say (always have), and my RS SPL meter also registers ~ 70 dB after Aud XT. I'm just assuming that it's the inaccuracy in the meter (though it is uniform, just low) and leave things as Aud does it. Just means that my main vol is ~ -5 rather than -10 for BD's (and down ~ 5 dB for most hdtv).

Ok, after reading the posts above I downloaded the Room Mode Calculator. Plugged in my room dimensions and I got the following:



So what does it all mean? I'm lost, no clue what I'm looking at.

Anything you care to post on what you have gleaned from that data?

Jeff

Let me preface this by saying I have read the Audyssey guide and I did search this thread and saw info that was close but didn't exactly address my questions.

I have and Onkyo1007, external amplifiers, bi-ampable speakers, an external active crossover, and tactile transducers...my goal is to make the best use of all of this equipment and get it all to play nice.

The crossover is an X2 from NHT. It has L+R+LFE inputs, LSub out + RSub out + LFE out, and L+R hi-pass output. I'll use the L+R preouts and the Sub1 output from the Onkyo connect them to the X2 inputs. The sub and the hi-pass outputs will be connected to the appropriate amps and the LFE out will go to the tactile transducer amp.

I know about checking the gain on the crossover and not having the tactile transducers powered on when running Audyssey setup.

Part of the goal of the active crossover is to filter the signal prior to amplification is to limit the power dissipated in the passive crossovers in the speaker itself? <-That's sort of a question
Assuming that's the case, is it still recommended to set the crossover's LPF as high is it will go prior to running the setup, or would it be better to set it closer to the actual crossover frequency? I understand that a lower crossover point will introduce delay which in turn can mess with Audyssey's distance measurements, but is that significant if I don't touch the LPF knob after running the setup?