"Official" Audyssey thread (FAQ in post #1) - Page 107

Originally Posted by gurkey

Because the Audyssey system seems to be very sensitive to mike positioning, I face the problem of having - due to rooms constraints - the front speakers at different heights:
- Left front is at ears height
- Center is below TV and considerably below ears height
- Right front is quite a bit above ear height
- Surrounds are somewhat below ears height

Because of the relatively short switching delays between individual speakers during measurement, I am not able of swiveling the mike perpendicular to the axis of the individual tweeter.

What to do ?

Originally Posted by audyssey

You can "transfer" the MultEQ filter to the Manual Parametric EQ. However, that is a very non-optimal approximation. Not only do you go from several hundred filter coefficients to 13 bands, you also lose the ability to correct in the time domain. "Manual" is not an Audyssey mode. It is a simple parametric equalizer.

Chris

Originally Posted by craig john

Chris has answered this so many times that I'm sure he's tired of repeating himself. Therefore, I'll take a stab at it.

Onkyo doesn't label speakers as "Large" or "Small", (and this is a good and appropriate thing!) They label them as "full-range" or they label them with a crossover point. Although unconventional, this is actually much more appropriate nomenclature. A speaker designated as "full range" is sent a full range signal, just like the "Large" speakers are in a conventionally labeled system. Any other situation than "full range" has a crossover applied to it and the bass is filtered off and sent to the sub. This is the same as the "Small" setting in conventional nomenclature.

You can "raise" any crossover point and still have the Audyssey filters in place. However, if you lower the crossover point, Audyssey will only filter down to the crossover point it found for that speaker.

In your case, you could reset your fronts and surrounds to have a crossover, (i,e., set them to "Small"), and then try different crossover points. I would start with 80 Hz and see how it sounds. Then use trial and error from there. (By the way, while we're on the subject of nomenclature, the "surrounds" in a 5.1 system should be placed at your sides. The "rears" are the 6th and 7th speakers in a 7.1 system and should be placed in the "rear": http://www.dolby.com/consumer/home_e...omlayout2.html)

I would not lower the CC crossover as you lose any Audyssey filtering below 150 Hz.

The sub crossover in the receiver is applied *only* to the LFE channel, not the entire subwoofer output. Audyssey recommends setting this to 120 Hz, which is the "brickwall" filter used in the recording of the LFE channel.

The crossover located on the back of your subwoofer should be disabled, (or, if it can't be disabled, set to it's highest point.) The Bass Management in the receiver is handling all the necessary crossovers, and doesn't need (or like) the assistance of the crossover in the sub.

Also, here is a link to the Audyssey FAQ:
http://www.audyssey.com/faq/index.html#parameters

Craig

Originally Posted by enzo-ita

Hi Chris,
this post drives me to a question.
Can you explain in simple words which is the difference, and therefore the advantage of correcting in the time domain versus correcting in the frequency domain?

Thanks

Originally Posted by dlcockrum

Hey Chris,

I just visited a AVS Forum thread called "High End 7.1 Processor" (please be warned before you visit that there are some bigtime ego's taking personal shots at each other) that talks about the NAD version of Audyssey. While I am not sure about the claims of it being superior to "regular" Audyssey, it does further an idea that I have pondered about expanding the sound options that Audyssey, and specifically Audyssey Pro, could offer. It seems like it would be great if you could start with the "stock" Audyssey curve and tailor the bass and treble curves to your taste to some degree. Is this feasible?

Originally Posted by dlcockrum

jsmiddleton4,

Thanks for the feedback. I have a Onkyo Pro 885 - I think the capability you mention is only available in Denon's implementation. I really wish that Onkyo chose to allow this and also the selection of the Audyssey roll-off curve like Denon did. Additionally, adding a few "custom" curve options like the NAD curve and others would be cool.

Originally Posted by audyssey

Enzo,

The main advantage comes from capturing the data in the time domain, even before you create the correction filters. A method that uses pink noise relies on what is called steady-state. That means that you don't have any information about what part of the signal you are measuring came directly from the speaker or from later reflections. A parametric or a graphic equalizer is then used to manipulate the frequency response by cutting or boosting. Because of the types of filters used to implement these types of equalizers, you can't correct with a very fine resolution because as your bands get narrower they start to cause serious phase problems that are audible.

But if you capture in the time domain, you have a different picture of the signals from the speakers. You can see the direct sound and the later reflections. This information can be used to create a filter that weighs the problems in the room more selectively and thus produce better results. The types of filters used here are such that they optimize the time domain response and the frequency domain response simultaneously. Instead of relying on a few bands they use hundreds (or thousands) of points (called taps) to model the measured response and then invert it. A graphical representation of the process is shown on the Audyssey website in a series of pictures that start here:

http://www.audyssey.com/technology/graphs/graph1.html

Chris

Originally Posted by automatic9362

Hi Chris,

I have a question about mic placement. Does placing the mic on the backrest of the couch cause any negative effect on the measurement? Is it alwas better to use a tripod instead?

Originally Posted by David Barteaux

Thanks Craig.
All my speakers are Klipsch THX. I am curious to know if I should run Audyssey again on my Onkyo 805 as is sets crossover correctly (80 Hz) for every speaker except the front left/right channels. It sets those speakers to Full Range.
From what I understand I can just raise the crossover to 80Hz on my left/right speakers and this will be ok?

Originally Posted by enzo-ita

Thanks,
I do not know if this question can be answered because it may fall into the secrete sauce domain , but I would like to know how the filters works on the signal.
I mean, when we use a parametric equalizer, we are changing (as far as I understand) the loudness of a range of frequency (the band) increasing or decreasing it by some dB and this is simple to understand.

Watching at the graphs of the time domain correction, I see that not only the loudness is changed for the first spike but also that it is shifted timewise, I also can notice that further echos are flattened down.

How can you cancel the echoes ? Do you generate a opposite signal for the echoes or simply shifting the spike you obtain a self cancelling of the echoes?

Thanks

ciao

Originally Posted by Eric Carroll

I have a very serious mode at 31 Hz I want to correct. I hesitate to call this a room mode, because it is actually a mode that excites a specific corner of the house, outside the room. This mode is considerably more audible in this house corner than other sub frequencies. The room itself is heavily soundproofed and acoustically treated, with a under-riser bass trap, acoustically eliminated rear wall, and side wall absorption. Also, if it matters, I have two rows of surround speakers (direct, not dipole) and a single rear speaker.

I want to tame this mode so that I can increase volume without exciting the house mode.

Right now I have a Krell Showcase which has a GEQ capability that can very grossly correct the mode.

I am trying to understand if Audyssey will help me with this problem. Will it sense this outside-the-room mode and correct for it? If not, can I tweak the room correction at 31 Hz to put some increased attenuation in?

If this is something that a specific version will do (i.e. Onkyo vs. Denon vs NAD) or if a Pro version is required, I would like to understand that so I can include the consideration in my next purchase of an HBR capable SSP.

Thanks for any assistance.

Originally Posted by audyssey

Enzo,

With a parametric equalizer ...........Chris

Originally Posted by audyssey

Eric,

Corners are the perfect place for modes to be the most severe. The energy from standing waves is highest near walls and when you have three of them in a corner you get the maximum effect. That's also the reason that bass absorbers are the most effective when placed in corners. It seems odd that this mode is only audible outside the room. Is the room fully enclosed with a door or is this an open plan? 31 Hz corresponds to a room dimension of about 17 ft so there must be some dimension of that order involved in causing this.
Chris

Originally Posted by jsmiddleton4

Nordo,

Or with networked enabled receivers that all of the data Audyssey captures could be sent out so we could graph it ourselves like with Adobe's SVG, etc. Similiar to what is being done with many internet routers to map bandwidth, etc.

Originally Posted by jsmiddleton4

dl...

You can do this somewhat. You can copy the Audyssey curves to the manual eq settings and then use the manual eq for your adjustments. Then you can tweak those using Audyssey as a starting point. As Chris has noted though its not a perfect solution as you are talking multiple pieces of information and putting them into the eq freq bands of the manual eq capability.

But you would be taking the Audyssey curves as a base line and then tweaking them as you see fit.

Originally Posted by chuck.fowler

Hi folks,

I am currently considering the purchase of a new A/V receiver and I am trying to understand the differences between the versions of Audyssey in them and how important they would be in my environment. I am looking at 2 different Onkyo receivers, the 605 and the 705. The 605 has Audyssey 2EQ while the 705 has MultEQ. Based on my limited understanding of the differences between them, MultEQ essentially includes more measurement positions and includes filters for the subwoofer and an additional filter for satellites. Is this a fair assessment?

In my home, I have a 5.1 system that includes a sub that is inline between the amplifier and main speakers, (i.e. the speaker out of the sub goes to the main speakers). My main speakers are relatively small bookshelf speakers high off the ground. I have done everything I can to optimize speaker location but my degrees of flexibility are very limited (which is why the subwoofer speaker out is connected to the main speakers, for example).

What I am trying to understand is how much incremental value Audyssey MultEQ would provide me? Since my subwoofer is inline with the main speakers, it is not going to be seen as a sub by Audyssey, I presume. Thus, I believe the Audyssey filters targeted at the sub will not have any effect. Will the additional measurement positions help significantly? I am not looking for anything absolute, of course, just a sense of where MultEQ provides the most value. I can then factor it in with other considerations as I trade off the Onkyo 605 vs 705.

Thanks for any help you can provide.

Chuck

Originally Posted by jsmiddleton4

kal,

And your point is what? Is there a different way to manually edit the eq curves Audyssey creates?

Originally Posted by jsmiddleton4

kal,

And your point is what? Is there a different way to manually edit the eq curves Audyssey creates?