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#1 ·

I've been in several threads lately where the topic has been all about Audyssey and I've noted that there's not actually a thread specifically for it. There's one that seems to be about it, but it's titled as being about the Denon 3806. Audyssey, of course, exists in far more receivers than the 3806 nowadays, so I thought I'd throw a starter into the pool to see if people were interested in having one thread to discuss all Audyssey issues/comments/questions/stories/impressions that they've come up with from their personal receiver-experiences.


Myself, i was quite anti-Audyssey when I first came across it. My ears were quite used to what they'd had before which was very bass & treble heavy. Time has passed and I've really come to understand the strengths of Audyssey and respect the clean, flat signal that I now love and enjoy (and couldn't imagine being without). I'd love to hear from anyone else that wants to chime in or discuss issues.


Basic starter-links:


The Audyssey homepage .


The types of Audyssey implimentations in different receivers.



The Audyssey FAQ


The Audyssey setup guide


====

Audyssey tips:

Microphone Placement


The microphone has been calibrated for grazing incidence and so it must point to the ceiling during calibration. Any other orientation will produce incorrect results.


The microphone response has been calibrated to match (on average) the response of an industry-standard ¼ instrumentation microphone. It is critical to use the microphone that came with the receiver and not one from another model that may have a different calibration curve.


It is also important to place the microphone on a tripod or other stand so that it is at ear height. We strongly recommend against holding the microphone in your hand because this can give rise to low frequency handling noise that will cause the MultEQ filters to compensate by cutting those frequencies. Furthermore, it is not recommended to place the microphone on the back of the couch or recliner. If a tripod is used, care must be taken to ensure that the microphone is placed at a height just above the seat back so that reflections from the seat do not cause problems at higher frequencies.


The first microphone position is used to calculate the distances to each loudspeaker and subwoofer and set the delays. It is also used to measure and set the trims. So, it is important to place the microphone in the main listening seat for the first measurement.


MultEQ measures the background noise level in the room before playing the test signal from each speaker. For the measurements to be valid, the signal to noise ratio must be above a certain threshold. If it is not, the test signal from that speaker will repeat at a higher level. If the noise in the room happens to be higher during some of the speaker measurements, then the test signals from those speakers will sound louder than the test signals from the other speakers. This does not affect the calculation of trim levels. If the room noise is too high even after the test signals increase in level, then an error message will be displayed warning the user that measurements can not be completed.


After the first position is measured, MultEQ measures other positions in the room around the listening area. These do not necessarily have to be in each individual seat. The idea is to capture as many points around the listening area as possible so that the acoustical problems that affect the quality of sound within that area are minimized.


For example, we recommend taking 3 positions on the couch facing the TV and then 3 more positions about 3 feet in front of the couch and parallel to the first three. Measurements up against the back or side walls should be avoided.


Some loudspeakers have rather problematic responses when measured off-axis (i.e. more than 15° away from the imaginary straight line that points to the listening position). In these systems, measurements taken too far away from the center line will show a reduced high-frequency response that may result in overcorrection and thus overly bright sound. Although it is difficult to predict which type of loudspeaker will have these off-axis problems we have most often observed them in poorly-designed multiple-driver arrays that exhibit very high off-axis lobing. In these situations we recommend a tighter calibration pattern centered around the main listening position and making sure that the mic is not placed in extreme locations and certainly not outside the plane of the front main speakers.

Checking the Results


Once MultEQ calibration is complete the results are stored in the receiver memory.


It is important to activate MultEQ by selecting one of the target curves. This is not performed by default after the calibration is finished and must be selected by the user. In a THX system we recommend using the Flat setting that allows the re-equalization to work as intended. In other systems, we recommend Audyssey for movie playback and Flat for music playback. Unfortunately, the music industry does not have any mixing standards like the movie industry so some music program material may sound better with the Audyssey setting. Front Align also uses the Audyssey process, but it does not apply the filters to the two front loudspeakers. Manual is not an Audyssey setting and does not use MultEQ filters. It is a simple parametric equalizer and will be subject to all the limitations that come with parametric EQ.


Small vs. Large speakers. This is the most commonly discussed topic by MultEQ users. The first thing to understand is that it is not a personal insult to your system if your speakers were detected as Small. It simply means, that in the room they were measured the - 3 dB point was detected at 80 Hz or above. This may happen even if the manufacturer's spec shows that the speaker is capable of playing lower. In fact, there are several benefits at crossing the speakers over at 80 Hz that have to do with power handling and headroom in the bass region that will be handled by the subwoofer amplifier.


The second most common question also relates to Small vs. Large. In the Denon receivers, MultEQ will designate as Large any speaker that has a -3 dB point below 80 Hz. For non-THX speaker systems this is an arbitrary definition that often causes confusion. All it means is that the speaker will not be bass managed unless the user tells it to be. Because Audyssey is not in charge of bass management, we have to abide by the manufacturers' rules and simply report the information found by the measurements to the bass management system.


In situations where the speakers do not play significantly below 80 Hz, an additional step must be taken to make sure that there is no loss of bass information. The user must set the speaker to Small manually so that bass management is performed properly.


Polarity: MultEQ checks the absolute polarity of each loudspeaker and reports it to the user. This is simply a report and does not affect the subsequent calculations in any way. It just asks you to check the wiring to make sure it is connected properly to each speaker. Sometimes we get false alarms. This is usually because the speaker has a driver (usually the mid-range driver) wired out-of-phase intentionally to make up for some problems at the crossover region. If a phase warning is shown, it is not a cause of alarm. Simply check the cables and hit Skip if everything is fine. Again, this does not have any effect on the EQ results.


Subwoofer distance: in many active subwoofers it is not possible to defeat the low-pass filtering. That means that the pre-pro bass management filters will be on top of the low-pass filters inside the subwoofer. The built-in low-filters introduce a delay to the signal coming in (because they have poles). This delay is seen by MultEQ as acoustical delay and is reported in the results. That is why sometimes the subwoofer distance is reported to be longer than the physical measured distance. The setting should not be changed because the blend between the sub and the satellites has been designed based on this time delay.


The design constraints for MultEQ were that it (1) must fit within a small portion of the DSP so that other processes can also run and (2) it must use FIR filters because of the well-known artifacts that IIR filters cause particularly in the time domain response. As it turns out, these two requirements are contradicting. In order for FIR filters to be effective and capable of correcting to low frequencies, they must consist of several thousand coefficients (taps). The problem is that the CPU power required increases with the number of taps, hence the dilemma. What we did at Audyssey was to come up with a different way to partition the frequency axis so that we can use fewer taps and yet not completely give up on low frequency resolution (and therefore low frequency correction). This allows us to take a 512 tap filter that would normally have a resolution of 94 Hz (meaning that any peak or dip narrower than 94 Hz would be missed) and significantly improve its resolving power. The resolution of the filter actually varies continuously with frequency and starts at around 10 Hz. Does this mean that MultEQ can correct an arbitrarily narrow peak or dip at 30 Hz? Of course not. The reality is that in the MultEQ XT version found in receivers, we can correct broader features below 100 Hz better than narrow ones. For example, a lump that is half an octave wide at 50 Hz can be fixed. A narrow dip or peak that is 1/3 or 1/6 octaves wide and centered at 30 Hz will be improved, but not eliminated.


The on-screen display in the receiver has very limited graphics. Therefore it is not possible to really show what the MultEQ correction filter is doing at all frequencies. It appears to only be operating on 9 bands like a parametric equalizer, but this is not the case. What is shown is a very crude approximation to the MultEQ correction and it should not be used to read exact values of cut or boost at the 9 frequencies shown.


Furthermore, there is no display for the subwoofer filter. This doesn't mean that there is no subwoofer correction. It was not added to the display because of interface and memory considerations.


(tips by Chris, CTO, Audyssey Laboratories)
 
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#14,581 ·

Quote:
Originally Posted by audyssey /forum/post/16472262


Here you go:
http://www.avguide.com/blog/playback...sey-dsx-part-2

I am still at a loss as to why "wides" and "heights" were developed and sent to market *after* the "surround backs"? If the wides and backs are more beneficial to the listener why were we (the public) shown and offered the surround backs first? It just doesn't make any sense. Shouldn't these electronic manufacturers be developing and implementing the most advantageous devices to be offered to the consumer? Why give us something inferior first and then later show us something superior? I can not believe that these new wides and heights were not known to be superior before the surround backs were marketed. It feels as if I've been decieved and led by the nose down the wrong road. I do realize the cut throat nature of business but this really rubs me the wrong way!
 
#14,582 ·

Quote:
Originally Posted by JimP /forum/post/16471622


Even excluding what Council is experiencing, for a subwoofer EQ system, it would appear that the version of Audyssey installed in your Denon 3808 isn't doing that great a job of equalizing. Is that a fair assessment?


or could part of this be due to a microphone correction file that comes into use when Audyssey is turned on?

As mentioned in my post "these measurements are at line level from the Pre-amp output of the 3808". What they show is the signal that is sent to the speakers, they are not in-room measurements.




Chris,

Hakka(and maybe another, yet to confirm) has mentioned on DTV forum he is seeing the same low frequency boost, also using a Denon AVR-3808.


cheers
 
#14,583 ·

Quote:
Originally Posted by baronzemo78 /forum/post/16454215


Chris and or Larry,


In my basement home theater, I can't do side surrounds on the walls, and will be mounting them in ceiling. The back surrounds will be on a back wall several feet away from the primary listening position.


For the sides wouldn't I want dipoles so the effect of the side surrounds coming from above would be limited?

Hi,


As I mentioned earlier, I think dipoles can be useful when space is limited and speakers are being located close to audience members.


It is recognized that in-ceiling installations are compromises that sometimes can't be avoided. Ceiling dipoles might be your best bet, but it should be noted that more sound will be directed downward toward the listeners than in the case of wall-mounted dipoles which direct more of the sound front and rear.


You may find this article relevant to your situation:

Atlantic Technology IWTS-8CMS In-Ceiling Tri-Mode Speakers


Larry
 
#14,585 ·

Quote:
Originally Posted by BWG707 /forum/post/16472644


I am still at a loss as to why "wides" and "heights" were developed and sent to market *after* the "surround backs"? If the wides and backs are more beneficial to the listener why were we (the public) shown and offered the surround backs first? It just doesn't make any sense. Shouldn't these electronic manufacturers be developing and implementing the most advantageous devices to be offered to the consumer? Why give us something inferior first and then later show us something superior? I can not believe that these new wides and heights were not known to be superior before the surround backs were marketed. It feels as if I've been decieved and led by the nose down the wrong road. I do realize the cut throat nature of business but this really rubs me the wrong way!

If you researched the history of the development of surround sound and you would gain the insight needed to answer your own question. If you are interested, this is a very good read. Surround formats were not born wholly formed; they evolved. And this is could be the next evolution.


One other thing; you speak as if the "market" were one monolithic, all-seeing entity. It is not. Anyone with an idea can set up shop. If the idea is powerful enough, others will support it. If enough support develops, then it has a chance of becoming a standard. Five-point-one is a standard and so it 7.1. DSX and its new speaker configuration is a new idea.


Just my $.02.
 
#14,587 ·
Chris,


The DSX spec for the height channels is 45 deg elevation.


If the ears are 44" from the floor, with 8' ceilings the speakers would be about 5 1/2' forward of the listening position.


I'd think that's a good amount closer than the average seating distance, so that for most situations the heights would end up on/in the ceiling between the seats and the front wall.


I'm actually warming to the idea, just want to make sure I'm understanding it correctly.


Re back surrounds, while I agree that our ears' location accuracy is much lower behind us, it seems clear that nothing can replace the qualitative effect of sounds coming from that direction.


That said, it does seem that this happens rarely in soundtracks.


But the fact that it happens at all means it's possible with only 5.1, so I wonder why soundtracks aren't mixed to exploit that more often.


I guess Audyssey's position is that the overall benefit is greater from a more expansive front soundstage that can be had most/all of the time vs. the occasional dramatic rear effect.


Back to the fronts, what output level capability relative to the L/R is required from the Wides and Heights?
 
#14,588 ·

Quote:
Originally Posted by audyssey /forum/post/16470828


That's not possible. The maximum allowed boost by MultEQ at any frequency is 9 dB.

Something else is causing this.


Dynamic EQ introduces additional boost (if you have it on) when you turn the volume down below 0. But even with that boost the level never exceeds the max level you get at reference 0 volume.


What source are you using when this happens? I wonder if there is an LFE issue that adds 10 dB twice. Try going to the Surround Parameters menu in the Denon and set LFE to -10 instead of the default 0.

Chris,


Thank you for the reply. I experience the boost no matter what source I use as long as Audyssey is turned on. For all my REW FR graphs, I have been using the V. Aux input on my Denon 3808. I watch movies on my PS3 and it is hooked up to my Denon via HDMI. The PS3 is setup for LPCM.


I tried setting LFE to -10. Bass is greatly reduced when I do this. I have followed many threads that mentions some equipment adding the 10db twice, especially when bitstreaming. I have not read about the PS3 doing this in LPCM.


I apologize now... I am not the smartest when it comes to AV stuff. It's just in the past year it become a hobby of mine.


That said, here is an REW FR graph depicting what my FR is without any EQ (purple), with Audyssey engaged (blue), and with Dynamic EQ engaged (green). I believe you will see my problem of really low frequencies being boosted at 12.5 Hz. This example shows a little over 11dB boost by Audyssey. This measurement was done in my main listening position.

Attachment 142896


Now if you look at the red line, this is when I set the room comp setting on my Ultras to "Medium". This is with Dynamic EQ turned on. This is what I have to do to keep my subs happy. What I don't like is that it neuters the 20Hz to 35Hz area as well.


Could you explain to me Audyssey's reasoning for boosting the natural rolloff so much? Also, is there anyway to keep it from doing so? What if I didn't have the room comp setting to work with as many other subs do not have this feature?


One last thing. If I set the room comp setting to medium before running Audyssey, Audyssey just boosts the low frequencies even MORE to compensate. Its like Audyssey knows that my subs are capable of hitting those frequencies.


I am truely sorry for the all the n00b questions. Everyone else in this thread is probably thinking I am totally nuts and that all the answers to my questions are very obvious.
 
#14,589 ·

Quote:
Originally Posted by JimP /forum/post/16470851


Counsil,


Did you say that you've got the Denon 3808 receiver and with what source device are you experiencing these peaks? Does your source device have an option for bass boost?

Jim,


I am experiencing the peaks when measuring with REW and when watching movies on my PS3 via HDMI using LPCM for audio.
 
#14,590 ·

Quote:
Originally Posted by MACCA350 /forum/post/16471247


Chris, Larry and Counsil,

I'll re-post my previous post as it seems it's been missed and is relevant to Counsil's issue........

MACCA350,


I saw your post a while back, but I just wasn't experienced enough to make an intelligent comment (and I'm still not!).


Thanks though. Hopefully it helps Chris with my issue.
 
#14,591 ·

Quote:
Originally Posted by MACCA350 /forum/post/16471262


The only two options currently at hand that I can see are:


1) Use your subs built in subsonic filter and increase the slope(or implement one if it doesn't have one)


2) Don't use Audyssey


cheers

I have tried changing my subsonic filter, but I have to plug/unplug ports in order to do so. SVS does not recommend that you deviate from their subsonic/plug configuration. Then on top of that, you to re-run Audyssey because doing so affects your whole FR, not just the low stuff. Then you're back to Audyssey boosting the low stuff all over again.


I don't like your second suggestion. I paid a lot of money just to get Audyssey. Thanks though.
 
#14,592 ·

Quote:
Originally Posted by pepar /forum/post/16473365


If you researched the history of the development of surround sound and you would gain the insight needed to answer your own question. If you are interested, this is a very good read. Surround formats were not born wholly formed; they evolved. And this is could be the next evolution.


One other thing; you speak as if the "market" were one monolithic, all-seeing entity. It is not. Anyone with an idea can set up shop. If the idea is powerful enough, others will support it. If enough support develops, then it has a chance of becoming a standard. Five-point-one is a standard and so it 7.1. DSX and its new speaker configuration is a new idea.


Just my $.02.

Just a couple quick points.

1)Don't tell me that Big Cooperations and Big Money don't push standards thru.2) I do understand the concept that sound formats evolved and this is what I am questioning; How did they evolve?3) Maybe it was bad wording on my part but I was using the term "market" to describe us, the consumers of these devices.

Thanks for the reply I 'm just curious as to what others think about the way that these formats are "evolving". I know that there has been talk about exactly how beneficial some of the new formats really are. Just looking for new opinions.
 
#14,593 ·

Quote:
Originally Posted by BWG707 /forum/post/16473981


Thanks for the reply I 'm just curious as to what others think about the way that these formats are "evolving". I know that there has been talk about exactly how beneficial some of the new formats really are. Just looking for new opinions.

Fair enough. But your previous post seemed like you had already formed an opinion, and a strong one at that. I apologize if I read too much into your wording.
 
#14,594 ·

Quote:
Originally Posted by JimP /forum/post/16471622


Even excluding what Council is experiencing, for a subwoofer EQ system, it would appear that the version of Audyssey installed in your Denon 3808 isn't doing that great a job of equalizing. Is that a fair assessment?


or could part of this be due to a microphone correction file that comes into use when Audyssey is turned on?

Actually Jim, Audyssey is doing a great job flattening out my FR. Look at my reply to Chris above for my latest FR graph. My system sounds great until I watch a movie (like Incredible Hulk) that has really low LFE content in the area that is being heavily boosted in the teen Hz.


Now let's take a movie like Pulse (the infamous lab scene). I can turn off the room comp feature on my subs and watch the scene at reference (0 MV). Since the scene has LFE content in the 18Hz to 25Hz area, my subs have no problems. Same thing with KFP. I can watch the Skidoosh scene at reference with no problem. Once I throw in WOTW, Incredible Hulk, etc. my subs can begin complaining around -20 to -25 MV. What it probably is... is that some movies have their LFE mixed really hot and that is all it is.


What's weird is that I can get a lot more SPL out of WOTW and Incredible Hulk if turn room comp to medium. For example, with room comp off, I can only get around 100dB peaks watching certain scenes in WOTW. If I turn on room comp, I can get 110dB peaks watching the same scenes. It just seems that the heavy boost in the really low Hz area is adversely affecting my subs' performance.
 
#14,595 ·

Quote:
Originally Posted by audyssey /forum/post/16472086


The graphs posted by MACCA are showing what the MultEQ filters are doing to produce a flat response. They are not showing the final subwoofer response. If you turn your screen upside down you will see what the overall subwoofer response is. If you then multiply it point-by-point with the curve shown you will get something very close to the flat curve.

So what's the verdict then Chris? Is MACCA making a valid point? Is he not giving enough information?


???
 
#14,596 ·

Quote:
Originally Posted by audyssey /forum/post/16470828


That's not possible. The maximum allowed boost by MultEQ at any frequency is 9 dB.

Something else is causing this.


Dynamic EQ introduces additional boost (if you have it on) when you turn the volume down below 0. But even with that boost the level never exceeds the max level you get at reference 0 volume.

Chris,

This max boost allowed, is it a limit of the filters alone? Or is it a limit of the combination of filters and the normalization process.

Quote:
What source are you using when this happens? I wonder if there is an LFE issue that adds 10 dB twice. Try going to the Surround Parameters menu in the Denon and set LFE to -10 instead of the default 0.

I had considered this also but discounted it(at least as far as my measurements are concerned) because the only difference between the traces is turning Audyssey on and off, so any +10db LFE boost issue specific to the AVR(and/or input) will affect both readings and hence negating it as the cause(at least in my situation).


cheers
 
#14,597 ·

Quote:
Originally Posted by counsil /forum/post/16474056


Now let's take a movie like Pulse (the infamous lab scene). I can turn off the room comp feature on my subs and watch the scene at reference (0 MV). Since the scene has LFE content in the 18Hz to 25Hz area, my subs have no problems. Same thing with KFP. I can watch the Skidoosh scene at reference with no problem. Once I throw in WOTW, Incredible Hulk, etc. my subs can begin complaining around -20 to -25 MV. What it probably is... is that some movies have their LFE mixed really hot and that is all it is.


What's weird is that I can get a lot more SPL out of WOTW and Incredible Hulk if turn room comp to medium. For example, with room comp off, I can only get around 100dB peaks watching certain scenes in WOTW. If I turn on room comp, I can get 110dB peaks watching the same scenes. It just seems that the heavy boost in the really low Hz area is adversely affecting my subs' performance.

I haven't tested Pulse, but WOTW has high level content down to DC.


cheers
 
#14,598 ·

Quote:
Originally Posted by MACCA350 /forum/post/16474591


Chris,

This max boost allowed, is it a limit of the filters alone? Or is it a limit of the combination of filters and the normalization process.

It is the total limit of MultEQ (filters and normalization).

Quote:
I had considered this also but discounted it(at least as far as my measurements are concerned) because the only difference between the traces is turning Audyssey on and off, so any +10db LFE boost issue specific to the AVR(and/or input) will affect both readings and hence negating it as the cause(at least in my situation).


cheers

Unless you are measuring with a Dolby encoded bitstream signal you are not feeding an LFE signal to the sub. There may be a 9 dB boost (max) at some frequencies below the roll off, but the subwoofer output is already many, many dB down acoustically. However, if you combine the 9 dB max boost from Audyssey with 10 more dB from the LFE boost incorrectly applied twice then you can push the sub into overload in that region.
 
#14,599 ·

Quote:
Originally Posted by counsil /forum/post/16474056


What it probably is... is that some movies have their LFE mixed really hot and that is all it is.

That is definitely an issue. As I said in an earlier post, it is possible to clip the subwoofer signal. If the mix contains near 0 dBFS content in all channels including the LFE track then this will happen no matter what you do.
 
#14,600 ·

Quote:
Originally Posted by noah katz /forum/post/16473762


Chris,


The DSX spec for the height channels is 45 deg elevation.

That's the ideal case. Obviously real world rooms will vary. The rule of thumb is "as high as possible above your front speakers"

Quote:
Re back surrounds, while I agree that our ears' location accuracy is much lower behind us, it seems clear that nothing can replace the qualitative effect of sounds coming from that direction.

True. A sound effect that is hard panned behind you will require a speaker there. But, there are so few of those that you won't miss it. The front wides and heights will give you much more benefit with all other content.

Quote:
But the fact that it happens at all means it's possible with only 5.1, so I wonder why soundtracks aren't mixed to exploit that more often.

It's the "Exit sign effect". Directors hate to put sounds that direct your attention away from the screen. Most people will turn their head in the theater and all they have to look at is the Exit sign...

Quote:
I guess Audyssey's position is that the overall benefit is greater from a more expansive front soundstage that can be had most/all of the time vs. the occasional dramatic rear effect.

Yes.

Quote:
Back to the fronts, what output level capability relative to the L/R is required from the Wides and Heights?

The same as all the other channels in the system.
 
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