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"Official" Audyssey thread (FAQ in post #51779) - Page 2060

post #61771 of 70911
Quote:
Originally Posted by beastaudio View Post

What AVR was swapped in btw?

 

I left that out on purpose as I was not addressing receivers (per se). I will say I have tried over a dozen receivers in the room with two afterwards.

 

Quote:
Originally Posted by batpig View Post

Charles -- what you describe sounds like it has nothing to do with XT32. MultEQ just calibrates EQ filters for the speakers, it has nothing to do with volume levels of each speaker. If you felt like "the surrounds were missing" that really doesn't sound like an EQ issue.

 

I think it does point to a EQ issue (or receiver itself?) as the level of the speakers were fine. The dynamics weren't there... could one say perhaps they don't belong there... I simply know I didn't prefer it. Among all of the receivers I have used in the room the biggest (obvious) difference was XT32.

post #61772 of 70911
Quote:
Originally Posted by Charles R View Post

Quote:
Originally Posted by beastaudio View Post

What AVR was swapped in btw?

I left that out on purpose as I was not addressing receivers (per se). I will say I have tried over a dozen receivers in the room with two afterwards.

Why would you leave that part out? This is a science forum after all, not a product specific forum where you might get flamed for such a thing eek.gifbiggrin.gif I think your direct opinion between the two while possibly not an Audyssey thing is still relevant.
post #61773 of 70911
I'll give feedback. I have an Integra 70.2 (Onkyo) and I have the exact impression posted here. The surrounds are dead and lifeless. I had to swap it out for a while with a Harmon Kardon 7200 and the surround envelopment was incredibly better. The HK does not have Audyssey but in sound quality it absolutely blows the Integra away . If I didn't need HDMI switching the HK would remain in my theater. Sounds like an Onkyo thing.
post #61774 of 70911
Quote:
Originally Posted by chambers1517 View Post

I'll give feedback. I have an Integra 70.2 (Onkyo) and I have the exact impression posted here. The surrounds are dead and lifeless. I had to swap it out for a while with a Harmon Kardon 7200 and the surround envelopment was incredibly better. The HK does not have Audyssey but in sound quality it absolutely blows the Integra away . If I didn't need HDMI switching the HK would remain in my theater. Sounds like an Onkyo thing.

Hello to the Guys who have problems with Onkyo/Integra AVRs. I think you will agree here that Audyssey is not made to make the surrounds dead and lifeless. Should this be the case you are facing then there is a need for a deeper troubleshooitng spree I suppose.

If you have come to this thread for help you have come to the right place, there are very knowledgable and at the same time very helpful members here who will be ready to assist you till you can scrap out the problem in your system. But in order to do that you will need to cooperate.

Simply saying surrounds with Audyssey in Onkyo/Integra gear are dead and lifeless will lead to nowhere. Can you be more specific and detailed so that others can understand your situation? So many questions come to mind, but if you can describe your setup, mic placement procedures, trims and distance settings after auto-setup, whether you are using DEQ or not, etc. it would make life much easier.

But if you only want to give reticent feedback, sorry to say, but it will be pretty much meaningless and no progress will be made. On the otherhand, if your problem is solved everyone gains, you will have a working system, others will learn something from your troubleshooting case.

Agree? smile.gif
post #61775 of 70911
Quote:
Originally Posted by jevansoh View Post

Quote:
Originally Posted by kbarnes701 View Post

Quote:
Originally Posted by mogorf View Post

[QUOTE name="Q

Has anyone ever done any measurements of Audyssey's alleged benefits in the time domain?  Not arguing - wondering.

The claim made (by Feri in a recent post but I don't know if Audyssey has made the same claim, specifically) that Audyssey (any flavor) will/can tame early reflections is not only false, it is absolutely impossible.

I have done many measurements and have seen absolutely no change in the time domain regarding early reflections and my knowledge and experience in the field of acoustics tells me this is impossible anyway.

I only recall reading that Audyssey directly claims "Time Domain" correction, however. This could mean a lot of things and I'm not disputing that in some ways the time domain is affected by the FIR filter Audyssey uses per channel. IE: By implementing a filter (whether FIR taps or biquad from PEQ) to tame a 40hz peak in my own listening room which before EQ (but after treatment - don't yet have tuned absorbers to this frequency) was at about 600ms the effect of the filter is not only a flattened FR but also, by nature of the process, the 40hz mode now decays in 400ms so this can be considered "Time Domain" EQ'ing, even though it's more the effect than the direct intent of the Audyssey filter by itself.

The basic point though is that it is absolutely impossible to electronically get rid of, "[early] reflections shortly after the direct sound."

I use Audyssey XT, but know its limitations and have a properly treated room and external devices (AS-EQ1 and DSP1124P) to set a house curve and by properly treating the room, setting up the listener/speaker positions, and measuring "Pre-EQ" Audyssey doesn't have much to do but definitely adds that last 10% that gets me a text book FR with applied house curve and I wouldn't want to be without it.

I'm definitely not interested in arguing whether or not Audyssey can tame reflections as a little education in the field of acoustics proves this point nor do I have much time these days, but hope this helps clear a few things up.

--J

 

 

Hey J!!  The last time someone was resurrected was a couple of thousand years ago and he caused quite a stir!!  :)

 

Thanks for the confirmation of what I have always thought - I've never understood how a RC system can change the sound after it has left the speakers. 

post #61776 of 70911
Quote:
Originally Posted by mogorf View Post

Quote:
Originally Posted by kbarnes701 View Post

Has anyone ever done any measurements of Audyssey's alleged benefits in the time domain?  Not arguing - wondering.

Wonder no more Keith, I think you are just a few clicks away from seeing your own system's performance in the time domain (I presume you have made some measurements in REW with Audyssey on/off and saved those files as .mdat).

Here's an animated gif image made up of two waterfall graphs with Audyssey on/off. Disclaimer: this is by no means a precise and valuable measurement, it has been taken with my Audyssey mic, the sole purpose is to roughly illustrate how Audyssey is supposed to perform in the time domain, taken in my living room at MLP as a single point measurement with my Denon 2310 which only has plain MultEQ.

Red: Audyssey off, Green: Audyssey on


(Click on image to see a larger version)

Whaddaya think Keith?

 

Can you remake the graph following conventional forum guidelines on waterfall graphs?  

 

Could you also do it with XT32 - I have no interest in the old (and possibly flawed) versions of MultEQ, and suspect that anyone interested in this depth of discussion shares that with me.

 

And could you please make the graph bigger - I can barely read the figures on the axes as it is - there's no need to fart about with animated gifs - two decently sized graphs are perfectly comparable.

post #61777 of 70911
Quote:
Originally Posted by asere View Post

Quote:
Originally Posted by mogorf View Post

Some can, some can not! Some swear they can even hear the difference in a controlled A/B blind test. smile.gif Some say (like me) there is no need to sweat on the issue too much. The recommendation of a trirpod/ mic stand (with boom arm to be precise) is to avoid people using pillows or shoe boxes or other creative methods to ensure the seated ear level for their test mics that can easily have a negative effect on the results by throwing off Audyssey due to reflections off those nearby and relatively large(er) surface "creativities". smile.gif

REW can give you peace of mind but in the end if you cannot tell the difference with ears alone I see no point whether its a tripod or mic stand with boom arm.

 

The main purpose of using a mic stand (or a tripod if there is no proper mic stand available) is to eliminate further variables in the measuring technique used. If you balance the mic on top of stepladder, you might get a reasonable calibration, but if you don't the first advice you get will be that you should not balance the mic on a stepladder. There are also several good reasons not to use anything other than a proper stand (see the FAQ answer linked to below). A boom mic stand is much easier to use than a tripod and, being purpose designed to hold a mic, has some advantages over a tripod, which is purpose designed (usually) to hold a camera.  

 

You may well hear the difference between a calibration done with a tripod and that done with a mic stand - for example, some tripod heads can cause spurious reflections to enter the mic, thus giving a bad calibration which can certainly be audible.

 

If you only have a tripod to hand, then you may still get a good result - but you are more likely to do so, and with more facility, if you use a boom stand. As they cost only 20 dollars or so, it is a trivial cost in the context of a HT system.

 

d)1.   Do I really need to put the Audyssey mic on a tripod or stand?

post #61778 of 70911
Quote:
Originally Posted by kbarnes701 View Post

Can you remake the graph following conventional forum guidelines on waterfall graphs?

Nope, this graph, as I said, is not for detailed analysis, but for illustration purposes only and I beleive it serves that purpose. smile.gif
Quote:
Could you also do it with XT32 - I have no interest in the old (and possibly flawed) versions of MultEQ, and suspect that anyone interested in this depth of discussion shares that with me.

Nope, coz I don't have XT 32. eek.gif
Quote:
And could you please make the graph bigger - I can barely read the figures on the axes as it is - there's no need to fart about with animated gifs - two decently sized graphs are perfectly comparable.

Did you click on the graph Keith? smile.gif
post #61779 of 70911
Quote:
Originally Posted by mogorf View Post

Quote:
Originally Posted by kbarnes701 View Post

Can you remake the graph following conventional forum guidelines on waterfall graphs?

Nope, this graph, as I said, is not for detailed analysis, but for illustration purposes only and I beleive it serves that purpose. smile.gif

 

 

OK. Sorry then but I think it's a bit useless. Even for illustration purposes, there are good reasons why there are forum conventions for posting waterfalls.  As it stands, I don't believe it shows what you believe it shows. Jason's answer explained why I think.

 

Quote:
Quote:
Could you also do it with XT32 - I have no interest in the old (and possibly flawed) versions of MultEQ, and suspect that anyone interested in this depth of discussion shares that with me.

Nope, coz I don't have XT 32. eek.gif

 

What??????  !!!!!!!!!!!!!!!!!  eek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gifeek.gif!  It cannot be, surely. You are the same Feri who has told me so many times that XT32 does this and XT32 does that and so on and on?  smile.gif   Are all those posts of yours just academic, text-book stuff with no 'hands on' at all?  My gast is flabbered! 

 

Quote:
Quote:
And could you please make the graph bigger - I can barely read the figures on the axes as it is - there's no need to fart about with animated gifs - two decently sized graphs are perfectly comparable.

Did you click on the graph Keith? smile.gif
 

 

Hehe - yes I did, but it didn’t help much.

post #61780 of 70911
Quote:
Originally Posted by kbarnes701 View Post

Quote:
Originally Posted by jevansoh View Post

Quote:
Originally Posted by kbarnes701 View Post

Quote:
Originally Posted by mogorf View Post

[QUOTE name="Q


Has anyone ever done any measurements of Audyssey's alleged benefits in the time domain?  Not arguing - wondering.


The claim made (by Feri in a recent post but I don't know if Audyssey has made the same claim, specifically) that Audyssey (any flavor) will/can tame early reflections is not only false, it is absolutely impossible.


I have done many measurements and have seen absolutely no change in the time domain regarding early reflections and my knowledge and experience in the field of acoustics tells me this is impossible anyway.


I only recall reading that Audyssey directly claims "Time Domain" correction, however. This could mean a lot of things and I'm not disputing that in some ways the time domain is affected by the FIR filter Audyssey uses per channel. IE: By implementing a filter (whether FIR taps or biquad from PEQ) to tame a 40hz peak in my own listening room which before EQ (but after treatment - don't yet have tuned absorbers to this frequency) was at about 600ms the effect of the filter is not only a flattened FR but also, by nature of the process, the 40hz mode now decays in 400ms so this can be considered "Time Domain" EQ'ing, even though it's more the effect than the direct intent of the Audyssey filter by itself.


The basic point though is that it is absolutely impossible to electronically get rid of, "[early] reflections shortly after the direct sound."


I use Audyssey XT, but know its limitations and have a properly treated room and external devices (AS-EQ1 and DSP1124P) to set a house curve and by properly treating the room, setting up the listener/speaker positions, and measuring "Pre-EQ" Audyssey doesn't have much to do but definitely adds that last 10% that gets me a text book FR with applied house curve and I wouldn't want to be without it.


I'm definitely not interested in arguing whether or not Audyssey can tame reflections as a little education in the field of acoustics proves this point nor do I have much time these days, but hope this helps clear a few things up.


--J


Hey J!!  The last time someone was resurrected was a couple of thousand years ago and he caused quite a stir!!  smile.gif

Thanks for the confirmation of what I have always thought - I've never understood how a RC system can change the sound after it has left the speakers. 
I've pondered the possibility of RC taming reflection spikes as Audyssey claims to and reasoned that it would be a VERY difficult thing to implement in real time, not to mention that since the distances and therefore, timing delays would differ at different seating positions, this apparently would not be a possibility for ROOM correction, although theoretically possible for one position.

When coupled with the more than numerous ETC measurements showing absolutely no difference in the reflection spikes pre and post Audyssey, this would appear to indicate that it doesn't affect the early reflections the way their site (with the pretty but SIMULATED graphs show) would have us believe (cue Feri to claim something along the lines of, "but you can't confirm the accuracy of the measurements, and maybe you're measuring the wrong thing, the wrong way" or some such).

That said though, apparently there ARE RC systems that might potentially have the power to tame early reflections. Someone posted measurement graphs pre and post Trinnov (or was it ARC?) showing a significant reduction in the first reflection spike.


Max
post #61781 of 70911
Hi, Guys

Need your expert advice for the following.

I currently have a 9.2 set-up with Audyssey calibrated for Front Heights & Rear Surrounds. I have attached a hand-drawing of the respective speaker positions, with the distances drawn to scale. The Front Heights are not shown in the drawing as they're directly above the FL & FR.

Now I'm thinking to add Wide Left (WL) & Wide Right (WR) at the positions indicated, based on the "60-degrees" guideline. They'll be at ear height. However, at the positions indicated, they'll be just behind the 2 subs. My query is: At the positions, will the Wide Surround effects be "compromised"/"overwhelmed" by the subwoofers' bass?

PS: The 2 subs are at their best positions after having tried various locations. Hence, I won't move them or any of the existing speakers.

Thanks.

post #61782 of 70911
Quote:
Originally Posted by Ethan Ong View Post

Hi, Guys

Need your expert advice for the following.

I currently have a 9.2 set-up with Audyssey calibrated for Front Heights & Rear Surrounds. I have attached a hand-drawing of the respective speaker positions, with the distances drawn to scale. The Front Heights are not shown in the drawing as they're directly above the FL & FR.

Now I'm thinking to add Wide Left (WL) & Wide Right (WR) at the positions indicated, based on the "60-degrees" guideline. They'll be at ear height. However, at the positions indicated, they'll be just behind the 2 subs. My query is: At the positions, will the Wide Surround effects be "compromised"/"overwhelmed" by the subwoofers' bass?

PS: The 2 subs are at their best positions after having tried various locations. Hence, I won't move them or any of the existing speakers.

Thanks.

 

IMO, if the subs are on the floor and the Wides are on the wall at ear height, there should be no adverse interaction between the two.

post #61783 of 70911
^+1 Assuming these are not extremely tall subs. biggrin.gif
I considered a very similar arrangement but ended up with subs mid front and back walls.
Edited by SoundofMind - 5/2/13 at 8:47am
post #61784 of 70911
+2 -- don't think it will be an issue at all. In fact, I helped set up a DSX setup for a friend and it just so happened that their two subs ended up in the front corners in a wide room, putting them pretty perfectly at the DSX "wide" angles. They are both tall M&K subs, and we ended up putting the wide speakers (M&K SB-1000) on TOP of the subs, elevated slightly with some Auralex "Speakerdudes" which put them at a nice ear height and also provided some acoustic isolation from the beasts beneath. Worked like a charm. I don't think you should fear any adverse interaction from having the speakers in close proximity to the subwoofers.
post #61785 of 70911
Quote:
Originally Posted by djbluemax1 View Post

I've pondered the possibility of RC taming reflection spikes as Audyssey claims to and reasoned that it would be a VERY difficult thing to implement in real time, not to mention that since the distances and therefore, timing delays would differ at different seating positions, this apparently would not be a possibility for ROOM correction, although theoretically possible for one position.

When coupled with the more than numerous ETC measurements showing absolutely no difference in the reflection spikes pre and post Audyssey, this would appear to indicate that it doesn't affect the early reflections the way their site (with the pretty but SIMULATED graphs show) would have us believe (cue Feri to claim something along the lines of, "but you can't confirm the accuracy of the measurements, and maybe you're measuring the wrong thing, the wrong way" or some such).

That said though, apparently there ARE RC systems that might potentially have the power to tame early reflections. Someone posted measurement graphs pre and post Trinnov (or was it ARC?) showing a significant reduction in the first reflection spike.


Max

 

Hey Max - long time no type. Interesting topic. I know in my room that Audyssey did very little for reflections, but my treatments did a huge amount. Always seemed, instinctively, that Audyssey couldn’t do very much for time domain issues, except when there is a knock-on benefit as a result of frequency domain corrections, as Jason postulated.

post #61786 of 70911
From Trinnov:

quote:

"... deconvolution provides spectacular results when applied to the compensation of early reflections.

When a loudspeaker produces a wave front in a room, the walls produce secondary wave front. At the begining is is easy to identify each elementary reflections but after some time, the reflections are so numerous that it becomes impossible to separate them, it is the reverberation.

The Optimizer compensates separately and with different methods the early reflections and the reverberation. Deconvolution provides best results when only applied to early reflections, while minimal phase (or linear phase) equalization provides best results when applied to the reverberation.
When a loudspeaker is placed in free air or in anechoic chamber, only one wave front is produced at the listening spot.

Let’s consider the first reflection produced by a wall placed immediately behind the loudspeaker. The reflection against the wall creates a secondary wave front.

When the loudspeaker is producing a single pulse, 2 wave fronts are produced at the listening spot. When this condition is compensated with deconvolution techniques, the second wave front is strongly cancelled at the listening position, where any other equalization method would fail.

The result of deconvolution leads the loudspeaker to fire a second time after producing the primary pulse and to produce a second pulse whose wave front is the identical inverse to the wave front of the reflection. The inversed wave front produced by the loudspeaker cancels the reflection and the original single wave front is retrieved."

Unquote

For the full material with 3D presentations click here, please.
post #61787 of 70911
I am trying to re-run Pro but am getting a message that says firmware is not supported by multieq and to contact Integra. My firmware is up to date and I ran Pro a few weeks ago, has anyone else had this issue and what was the solution?

Thanks.
post #61788 of 70911
Quote:
Originally Posted by mogorf View Post

From Trinnov:

quote:

"... deconvolution provides spectacular results when applied to the compensation of early reflections.

When a loudspeaker produces a wave front in a room, the walls produce secondary wave front. At the begining is is easy to identify each elementary reflections but after some time, the reflections are so numerous that it becomes impossible to separate them, it is the reverberation.

The Optimizer compensates separately and with different methods the early reflections and the reverberation. Deconvolution provides best results when only applied to early reflections, while minimal phase (or linear phase) equalization provides best results when applied to the reverberation.
When a loudspeaker is placed in free air or in anechoic chamber, only one wave front is produced at the listening spot.

Let’s consider the first reflection produced by a wall placed immediately behind the loudspeaker. The reflection against the wall creates a secondary wave front.

When the loudspeaker is producing a single pulse, 2 wave fronts are produced at the listening spot. When this condition is compensated with deconvolution techniques, the second wave front is strongly cancelled at the listening position, where any other equalization method would fail.

The result of deconvolution leads the loudspeaker to fire a second time after producing the primary pulse and to produce a second pulse whose wave front is the identical inverse to the wave front of the reflection. The inversed wave front produced by the loudspeaker cancels the reflection and the original single wave front is retrieved."

Unquote

For the full material with 3D presentations click here, please.

Seems Legit.... I'm not very versed on trinnov but I have one question.

Wouldnt the "out of phase" inverse pulse also have a front wall reflection? What happens to that reflection? Seems like each time you destruct a wave you create another problem.....

However you would be pushing it further out in the time domain and if the destruction pulses were consecutive cancelling themselves each lower in gain you could push it out far enough in the time domain and low enough in gain to make it work....

Sounds cool.
post #61789 of 70911
Have some bad news to report about Audyssey's sub management.

Background: have a HRS 12 Sunfire 1000watt sub thats rated 18hz-100hz. I noticed some 'rattle' like sub distortion during 'the impossible' tsunami sequence. My sub is set to 3 out of 10 on the gain and the audyssey trim applied is -0.5db.

I contacted the sub company and we've been troubleshooting for the past few days. What we found was startling. The 'distortion' only happened in the 10-15hz sound spectrum. With audyssey off, there was no distortion at all during the bass sweeps. With it on, the rattling/gurgle was back. The technician re did the audyssey setup and the 'distortion' came back in the same range. Turns out Audyssey is boosting the subsonic 20hz region significantly.

The 'distortion' wasn't distortion at all either, it was the spider coil slamming into the cone and even just seconds of this type of abuse can damage my expensive subwoofer.


I've written to Audyssey and am waiting on a response on how I can enjoy Audyssey room correction in a way that doesn't damage or distort my subwoofer.
post #61790 of 70911
quite simple really, just get something that will Highpass your sub around its 18hz f3 point and the problem is fixed.

Feri, why in the world would you post a quote from a room correction system that shares virtually nothing with Audyssey's approach?
post #61791 of 70911
Quote:
Originally Posted by beastaudio View Post

quite simple really, just get something that will Highpass your sub around its 18hz f3 point and the problem is fixed.

Feri, why in the world would you post a quote from a room correction system that shares virtually nothing with Audyssey's approach?

simple is to try and build/buy a highpass at 18hz? Do you have a link to an 18hz high pass I can buy? thankfully I don't need to buy a new sub too....
post #61792 of 70911
Quote:
Originally Posted by beastaudio View Post


Feri, why in the world would you post a quote from a room correction system that shares virtually nothing with Audyssey's approach?

Good question beastaudio, because some people here say it's impossible. But if Trinnov can solve it with convolution (inverse filtering), then why couldn't Audyssey solve it? Big question! smile.gif
post #61793 of 70911
Quote:
Originally Posted by mo949 View Post

simple is to try and build/buy a highpass at 18hz? Do you have a link to an 18hz high pass I can buy?

Could be a good approach, on a second note I would try to put the sub at a different location and run Audyssey again to see whether the same problem persists or not. Could be a tough room boundary gain issue there (too close to corner or wall) that throws Audyssey off. You know what, just pull the sub into the middle of the room, we're not setting up the sub, but just trying to see whether the problem follows the sub at another location or not.
post #61794 of 70911
Quote:
Originally Posted by mal01 View Post

I am trying to re-run Pro but am getting a message that says firmware is not supported by multieq and to contact Integra. My firmware is up to date and I ran Pro a few weeks ago, has anyone else had this issue and what was the solution?

Thanks.

Good place to post this is the Pro thread.
post #61795 of 70911
Quote:
Originally Posted by mogorf View Post

From Trinnov:

quote:

"... deconvolution provides spectacular results when applied to the compensation of early reflections.

When a loudspeaker produces a wave front in a room, the walls produce secondary wave front. At the begining is is easy to identify each elementary reflections but after some time, the reflections are so numerous that it becomes impossible to separate them, it is the reverberation.

The Optimizer compensates separately and with different methods the early reflections and the reverberation. Deconvolution provides best results when only applied to early reflections, while minimal phase (or linear phase) equalization provides best results when applied to the reverberation.
When a loudspeaker is placed in free air or in anechoic chamber, only one wave front is produced at the listening spot.

Let’s consider the first reflection produced by a wall placed immediately behind the loudspeaker. The reflection against the wall creates a secondary wave front.

When the loudspeaker is producing a single pulse, 2 wave fronts are produced at the listening spot. When this condition is compensated with deconvolution techniques, the second wave front is strongly cancelled at the listening position, where any other equalization method would fail.

The result of deconvolution leads the loudspeaker to fire a second time after producing the primary pulse and to produce a second pulse whose wave front is the identical inverse to the wave front of the reflection. The inversed wave front produced by the loudspeaker cancels the reflection and the original single wave front is retrieved."

Unquote

For the full material with 3D presentations click here, please.

 

So will you next AVR have Trinnov then, Feri? wink.gif

post #61796 of 70911
Quote:
Originally Posted by kbarnes701 View Post

So will you next AVR have Trinnov then, Feri? wink.gif

I though it was you first Keith!smile.gif Have you seen the 3D slides? Fascinating, isn't it! smile.gif
post #61797 of 70911
Quote:
Originally Posted by mogorf View Post

Quote:
Originally Posted by beastaudio View Post


Feri, why in the world would you post a quote from a room correction system that shares virtually nothing with Audyssey's approach?

Good question beastaudio, because some people here say it's impossible. But if Trinnov can solve it with convolution (inverse filtering), then why couldn't Audyssey solve it? Big question! smile.gif

 

The question is not 'why couldn't they?' but 'why didn't they?'  Trinnov can do a lot of things Audyssey can't - from what I have read about it. I'd really like to give it a try. The main problem is that it isn’t implemented in any AVR/AVP that I want to own.

post #61798 of 70911
Quote:
Originally Posted by mogorf View Post

Quote:
Originally Posted by kbarnes701 View Post

So will you next AVR have Trinnov then, Feri? wink.gif

I though it was you first Keith!smile.gif Have you seen the 3D slides? Fascinating, isn't it! smile.gif

 

I've read a lot about Trinnov in the past. I am very impressed with a lot of the things it can do, especially the ability it has to 'relocate' the speakers to more ideal positions, which would be very beneficial for me. If it was available in a fully implemented form in a Denon, Onkyo or Marantz unit, that would be enough reason for me to swap. Sadly, it isn't. 

post #61799 of 70911
Quote:
Originally Posted by mo949 View Post

Have some bad news to report about Audyssey's sub management.

Background: have a HRS 12 Sunfire 1000watt sub thats rated 18hz-100hz. I noticed some 'rattle' like sub distortion during 'the impossible' tsunami sequence. My sub is set to 3 out of 10 on the gain and the audyssey trim applied is -0.5db.

I contacted the sub company and we've been troubleshooting for the past few days. What we found was startling. The 'distortion' only happened in the 10-15hz sound spectrum. With audyssey off, there was no distortion at all during the bass sweeps. With it on, the rattling/gurgle was back. The technician re did the audyssey setup and the 'distortion' came back in the same range. Turns out Audyssey is boosting the subsonic 20hz region significantly.

The 'distortion' wasn't distortion at all either, it was the spider coil slamming into the cone and even just seconds of this type of abuse can damage my expensive subwoofer.


I've written to Audyssey and am waiting on a response on how I can enjoy Audyssey room correction in a way that doesn't damage or distort my subwoofer.


Audyssey will almost certainly give you the runaround and deny that their technology could damage the sub by boosting it below its capabilities. During the measurement they calculate the lower limit (F3) of the sub and the filters taper off below that point to avoid boosting the sub below its lower limit. However, the subwoofer can still be boosted below this frequency due to the "normalization" problem that has been amply discussed in this thread (also something else which Feri will deny exists despite the large body of evidence). One thing you didn't mention is what receiver you are using? There seems to be some evidence that Audyssey corrected the normalization problem in more recent models.

I do think the suggestion of moving the sub and re-running Audyssey could be effective. As some background, the "normalization" issue is caused by Audyssey re-leveling the sub channel to match the levels of the other speakers after its EQ correction is applied. After EQ correction, Audyssey looks at a narrow frequency band in the subwoofer's response (centered around 60Hz according to Chris K) and then raises/lowers the sub level to compensate for any major cuts/boosts in the frequency response. For example, if the sub level is set to 75dB to match the other speakers, but there are some giant peaks in the sub response in the 40-80Hz range that need to be tamed, after EQ the perceived level of the sub will now be well below 75dB because of the removal of those peaks. To maintain perceptual balance with the EQ filters enabled, Audyssey will "normalize" the subwoofer channel to the other speakers by globally boosting the subwoofer level to keep the perceived level the same with Audyssey on vs. off. Unfortunately, the global level boost when normalizing does NOT get filtered below the F3 of the sub, so if there is a large boost needed it will end up providing a lot of extra energy below the sub's F3. Relocating the sub to a different spot in the room may mean that Audyssey's EQ filters don't have to do as much cutting and lead to a more moderate normalization which won't overtax the sub.


See this post for some more info and links to other posts discussing the issue: http://www.avsforum.com/t/795421/official-audyssey-thread-faq-in-post-1/50430#post_21653246

And here is a graph from this post which shows a worst-case-scenario situation for this problem.




You can see some huge cuts in the 45-70Hz range in the equalized pre-out measurement (blue line) and then Audyssey raises the global level to match the un-EQ'd pre-out measurement (purple line).... but unfortunately this in a giant boost below 15Hz.
post #61800 of 70911
Batpig, thank you. After reading it the from that perspective I think you may be right about my chances of a reply, but the tests we did confirm that with audyssey OFF the sub can 'roll things off' properly. The audyssey seems to try and 'defeat' this roll off and boost the subsonic levels. We were literally shocked at what audyssey was doing.

. I really am just coming up to speed ont he technicial specifics in a big way....i know more now about subs than I ever really wanted to biggrin.gif but I am still very much a laymen and don't have any software or readings of that nature.

The receiver I am using is a run of the mill 1612 Dennon with the MultiEQ product. My sub is 2 ft away from the corner of my living room and about 3 inches from the wall. Its a forward firing Sunfire HRS 12.
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