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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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#72,542 ·
Forgive me if this question has already been asked - I tried to search the thread but didn't see my key phrase come up, despite a number of hits in the search.

Question is this: I'm looking at getting a new AVR soon with dual subwoofer outputs, Audyssey XT32 and Sub EQ HT. But I want to run a four subwoofer configuration. Can I hook up two subs to one output using a y-splitter, two to another output with another y-splitter, and then have Audyssey do its subwoofer calibration?

Or will it screw it up because it thinks it is measuring one subwoofer at a time, when in reality it is measuring two at a time?

For what it is worth all four subs will be identical and will be placed around the room to smooth out bass response.
I have this exact configuration--the Denon 4520 and four identical Hsu ULS-15 subs. I have it configured exactly as you have suggested, a pair of subs on each channel.

I would like to add several more tips: Make sure each sub pair is gain-matched. To do this, play the AVR pink noise level-setting tone for the sub channel, turn off one sub, place an SPL meter a couple of inches in front of the dust cap of the other sub, and adjust the sub's gain to something close to 90dB. Repeat the process for the second sub, making sure its gain achieves the same 90dB reading. I use 90dB for the near-field measurement because this results in ~75dB at the MLP. You will be asked to set the sub levels at the beginning of the Audyssey calibration, so if the 90dB gain matching registers higher or lower than 75dB +/- 2dB in the calibration, go back to the gain-matching step and adjust both sub gains slightly higher/lower (preserving the gain-matching, of course).

And second, since Audyssey can only set one delay (distance) setting for each of the two sub channels, try and place each sub in a sub pair equidistant from the MLP. For example, one of my sub pairs is placed on the front wall at the 1/4 and 3/4 spots, both the same distance from the MLP.

And finally, if you have the measurement tools, you should follow the "sub distance tweak" procedure to ensure the subs are in phase with the main speakers. The procedure ids described here: https://dl.dropboxusercontent.com/u/9653266/Audyssey Sub Distance Tweak Procedure Oct 2013.pdf
 
#72,543 ·
Thanks so much guys!
 
#72,552 ·
Thank you very much for providing this link. I have just made it through majority of it. I learned some interesting things, but this is only the tip of the iceberg for me.

Just to recap:

1) I am already plugged into my LFE port

2) I should try turning up my gain and then run Audyssey again? Rythmik instructions
recommended the gain at 0db for setup. What should I set the gain to?

3) I read that you can bypass the Audyssey initial setting of 75db. Mark Seaton recommended this in your post. I could not find a way to bypass it. It was making me either turn down my volume on the sub or cancel that I was going to use a sub for testing. I could not even keep my sub at mid volume for testing purposes.

4) After running MultEq, I should then run Dynamic Eq?

5) Turn off Dynamic Volume and make sure Dynamic Eq is turned on?


Earlier in the day before I posted this, I tried listening the the Audyssey subwoofer "too loud" and turning down the volume until I reached 75db. I also set the extension filter to high. Other than those two adjustments, I left all the recommended setup instructions from Rythmik. I will include pictures of my results. I then went into the settings manually and set the large speakers to "small" and the bass level from -5db to +3db. I did notice a considerable difference in the bass output when I put some music on. However, this time I also turned the volume (on the sub) up over half way and had a ton of background noise.

Results below from the following settings:

LFE Delay/Phase: 0
PEQ:Off Crossover: Max
Gain:0db Volume:Under middle (Required to get lower than 75db)
Bandwidth: Middle LowPass Filter: AVR/12
Frequency: Middle (40hz) Rumble Filter: Off/1 for one port
Extension Filter: 14Hz high damping
The idea is to get the sub trim somewhere like -3.5dB. This then gives you the option of running the sub a little 'hot' if you prefer a bit more bass after the Audyssey calibration (most do) without going into positive sub trim territory (which can clip the sub amp input on some subs). When you get to the screen where Audyssey asks you to set the level to 75dB, you can just skip past that screen if you wish. Just aim for a final sub trim, after cal, of about -3.5dB or even lower.

After the cal, Dynamic EQ defaults to on. Leave it there. You only need Dynamic Volume on for late night listening if you wish to avoid distrubing others. Both Dynamic EQ and Dynamic Volume are explained fully in the FAQ.
 
#72,553 ·
The idea is to get the sub trim somewhere like -3.5dB. This then gives you the option of running the sub a little 'hot' if you prefer a bit more bass after the Audyssey calibration (most do) without going into positive sub trim territory (which can clip the sub amp input on some subs). When you get to the screen where Audyssey asks you to set the level to 75dB, you can just skip past that screen if you wish. Just aim for a final sub trim, after cal, of about -3.5dB or even lower.

After the cal, Dynamic EQ defaults to on. Leave it there. You only need Dynamic Volume on for late night listening if you wish to avoid distrubing others. Both Dynamic EQ and Dynamic Volume are explained fully in the FAQ.
Thank you for the update. I am sitting down about to calibrate as I type. I was waiting on the arrival of my ground loop isolator. Audyssey originally had me at -5.0db. I then went back in and manually set it to +3, but you are saying that is too much. I have to read more about the gain and how that will help my bass output.

Heading in to give it another shot now!! Come on bass!!
 
#72,554 · (Edited)
This is a great forum and I see the usual suspects throughout. Thank you in advance for your input. It has been and continues to be greatly appreciated.

I have calibrated my system several times over the past few weeks, updating for new equipment and treatments. Most recently using XT, Audysee suggests a crossover for ALL speakers of 40htz (except center at 70htz). This includes in-ceiling speakers (Paradigm 60R-30) as well as side surrounds (B&W 704s). The results are quite good but I feel I am missing some impact from my subs. I do not listen consistently at reference level, but I do like to hear the foundation shake at the appropriate time. I have compensated by 1) moving in-ceiling speakers to an 80htz crossover and 2) raised the sub level from the AVR about 4db. My question(s): is this the right approach to adjust Audysee? Should I just cross everything over at 80htz? Should I go with the Audysee calibration and then just increase the subs to my liking? Please note my equipment listing below. Thanks again for your thoughts.
 
#72,555 ·
This is a great forum and I see the usual suspects throughout. Thank you in advance for your input. It has been and continues to be greatly appreciated.

I have calibrated my system several times over the past few weeks, updating for new equipment and treatments. Most recently using XT, Audysee suggests a crossover for ALL speakers of 40htz (except center at 70htz). This includes in-ceiling speakers (Paradigm 60R-30) as well as side surrounds (B&W 704s). The results are quite good but I feel I am missing some impact from my subs. I do not listen consistently at reference level, but I do like to hear the foundation shake at the appropriate time. I have compensated by 1) moving in-ceiling speakers to an 80htz crossover and 2) raised the sub level from the AVR about 4db. My question(s): is this the right approach to adjust Audysee? Should I just cross everything over at 80htz? Should I go with the Audysee calibration and then just increase the subs to my liking? Please note my equipment listing below. Thanks again for your thoughts.
Most people seem to increase their bass levels by a few dB after running Audyssey. See this FAQ answer for background:

f)5. Since I ran Audyssey everything sounds great - but where has my bass gone?

WRT to the crossovers, you are certainly right to consider raising them and letting the sub do the job it was designed for. I would start by raising them to 80hz but also try 90Hz and 100Hz if your sub is happy to play at those frequencies (it should be).

Here is some background from the FAQ on the issue of crossover settings:

c)2. Why do I often see advice to raise the Crossovers to 80Hz?

c)4. Is it OK to change the Crossovers from Audyssey's recommendation?
 
#72,557 ·
Larry Graham and Graham Central Station confirms crossing of at 80 htz (or just abouts) works best for music and that bass line I wanted hear. Sounds great. Thanks
 
#72,559 · (Edited)
Larry Graham and Graham Central Station confirms crossing of at 80 htz (or just abouts) works best for music and that bass line I wanted hear. Sounds great. Thanks
Hi quinn,

Actually crossover has nothing to do with music or film, yet it has something to do with the way our ears work. As audio frequencies get lower and lower our ears start to fail to detect directionality. Experiments have shown that below 80 Hz this phenomenon happens. We can hear the intensity of an explosion, but we can't detect it's direction. This is what is made use of when contents below 80 Hz are re-directed to subwoofer(s).

For more in-sights please refer to the blog Small vs. Large where you will get an explanation on how low frequencies vs. distance of our two ears on our head relate. (Link in my sig) :)
 
#72,560 ·
You said "teamwork", and I totally agree with you. ...So I remembered Robert De Niro using that line (word) in some of his acting movies. ...Then I googled Teamwork Robert De Niro, and that was the first entry.

That's all, it's only a movie, nothing to make of it but only the positive aspect, like a baseball team.
 
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