AVS Forum banner

Status
Not open for further replies.
13741 - 13760 of 79637 Posts

·
Registered
Joined
·
30,632 Posts

Quote:
Originally Posted by audyssey /forum/post/16222821


And don't forget: the camera adds 10 lbs

That's because it lacks Audyssey correction!!!


Kal (who has since changed his optometrist)
 

·
Registered
Joined
·
4,128 Posts

Quote:
Originally Posted by dewd /forum/post/16194281


What would cause my right speaker's distance to be reported as 1.0 FT?


I re-ran Audyssey MultEQ XT last night on my Onkyo 705 after I added 2 GRAMMA pads under my sub. For the past 8 months the distance has been reported correctly (8 to 8.5 feet). All the other speakers are reporting correct distances and the trims are reasonable (-1 to +1 on all but the sub, which is -9).

Did that only happen once or is it happening consistently? Noise or vibration at the mic can cause this. You can always manually set the distance since you already know it.
 

·
Registered
Joined
·
18,535 Posts

Quote:
Originally Posted by audyssey /forum/post/16222850


The "no bass" complaints are almost always due to two things:


1) Speakers are set to Large (Full Range) and no bass is sent to the sub

2) Person has a preference for bass levels higher than reference

FWIW, Audyssey set my mains from "small" to "large" changing the crossover from 60Hz to 40Hz. Will that affect where Audyssey places my sub distance?
 

·
Registered
Joined
·
1,678 Posts

Quote:
Originally Posted by heatwave3 /forum/post/16222129


My sub measurements with Audyssey were spot-on and I used a camera tripod with the legs retracted. I then place the tripod with the Denon microphone in 8 various locations on the main large couch directly in front of the HT. The couch has a high back and the microphone was below the highest point of the couch back and at speaker level (eyeballed) which is also about the same height as the average adult's ears when seated.

Your data-point supports the fact that not all furniture has mechanical resonance issues.


But for anyone who repeatedly gets a sub or speaker measurement that is within 6" of the height of the measuring mic + tripod while sitting on the couch/chair, then they should definitely consider switching to a boom based stand.
 

·
Registered
Joined
·
1,107 Posts

Quote:
Originally Posted by JonFo /forum/post/16223081


Your data-point supports the fact that not all furniture has mechanical resonance issues.


But for anyone who repeatedly gets a sub or speaker measurement that is within 6" of the height of the measuring mic + tripod while sitting on the couch/chair, then they should definitely consider switching to a boom based stand.

One other interesting note during my Audyssey setup was the fact that the very accurate settings I got for all 3 speakers and the Sub were taken in a somewhat messy family room. Large (4'x4'), low coffee table covered with my son's books and magazines spread out, newspapers on the couch, my wife's couch-blanket in a pile on the seating, etc. I didn't bother cleaning up since the room unfortunately is more often in this state than clean, other than the day after cleaning lady



There were alot of "things" to interfere with the signal such as the 2-story height of the room, large wall opening to kitchen, large wall opening to the living room etc. All the more reason I was impressed that Audyssey stood even a remote chance of getting the measurements accurately and did so "on the money". Its probably worth noting that the 2 large couches in the room are fabric and that the large recliner is leather.
 

·
Registered
Joined
·
1,678 Posts

Quote:
Originally Posted by audyssey /forum/post/16222866


Did that only happen once or is it happening consistently? Noise or vibration at the mic can cause this. You can always manually set the distance since you already know it.

Chris, Isn’t a correct distance calculation required by the algorithm if it’s going to set phase relationships correctly as it computes the filters?


The processor might apply the correct delay if the user overrides it to the actual distance, but might not the inter-speaker phase relationships of the computed taps be off?


As a corollary, I gather the measured impulses are only used to derive data and not used directly in any convolution, correct?


One of the purported benefits of Audyssey is that it’s temporally correct, so I’d think nailing the distances during measurement is a must.
 

·
Registered
Joined
·
1,678 Posts

Quote:
Originally Posted by Waboman /forum/post/16222898


FWIW, Audyssey set my mains from "small" to "large" changing the crossover from 60Hz to 40Hz. Will that affect where Audyssey places my sub distance?

I would not think it would have any effect on the distance.


Your Prodigies might easily measure as full-range.


The sub distance is computed by the impulse response from that speaker alone. And as we've been covering, it can be affected by mechanically induced noise.


Is your mic + tripod height at position #1 roughly the 'distance' reported by Audyssey?
 

·
Registered
Joined
·
4,128 Posts

Quote:
Originally Posted by JonFo /forum/post/16223342


Chris, Isn't a correct distance calculation required by the algorithm if it's going to set phase relationships correctly as it computes the filters?

No, the filters do not depend on the distance calculation.


There are two kinds of "time" corrections. One is to compensate for the difference in distance between speakers (actually the difference in delay experienced by the signal in each speaker and subwoofer). The second is to identify the time-domain response of the system. This is a signature of how the speaker-room system behaves as time passes. By "time" we mean a number of milliseconds after the direct sound has left the speaker and starts to reflect and interact with the room.


Getting the delays right is critical for imaging as we are very sensitive to variations in time of arrival of sound to each of our ears.


Getting the time domain response right is critical in mitigating the effects of reflections and other room interactions.


But the two are completely independent.
 

·
Registered
Joined
·
18,535 Posts

Quote:
Originally Posted by JonFo /forum/post/16223395


I would not think it would have any effect on the distance.


Your Prodigies might easily measure as full-range.


The sub distance is computed by the impulse response from that speaker alone. And as we've been covering, it can be affected by mechanically induced noise.


Is your mic + tripod height at position #1 roughly the 'distance' reported by Audyssey?

Audyssey is pretty much spot on for the distance on all 7 speakers. It's the .1 that is nowhere near what it should be.


To you recommend changing my mains to "small" and the crossover to 60 or 80Hz?
 

·
Registered
Joined
·
30,086 Posts

Quote:
Originally Posted by Waboman /forum/post/16222898


FWIW, Audyssey set my mains from "small" to "large" changing the crossover from 60Hz to 40Hz. Will that affect where Audyssey places my sub distance?
Quote:
Originally Posted by Waboman /forum/post/16223771


To you recommend changing my mains to "small" and the crossover to 60 or 80Hz?

Have you read/followed the Audyssey setup guide? And have you read the Audyssey FAQ, specifically this question ?


It is always recommended to switch them to small manually post-Audyssey.
 

·
Registered
Joined
·
18,535 Posts

Quote:
Originally Posted by batpig /forum/post/16223819


Have you read/followed the Audyssey setup guide?

Yes.


Quote:
Originally Posted by batpig /forum/post/0


It is always recommended to switch them to small manually post-Audyssey.

Got it, thanks.
 

·
Registered
Joined
·
1,668 Posts

Quote:
Originally Posted by PerfKnee /forum/post/16221365


It's reassuring to see that I'm not the only one having audyssey mysteriously report sub distance significantly less than physical. A half dozen people have reported such in this thread, and it seems to be about as common as the well understood case where audyssey reports greater than physical distance due to crossover induced delays.


Chris has acknowledged that he has seen this effect, sometimes with push pull subs, but he has not tracked down the actual cause of this phenomenom, and has not given any recommendations as to whether to manually tweak such cases.


The big question in my mind is whether this is messing with impulse response. In other words if you send a square wave through a system whose audyssey calibration placed the sub closer than physical, does the listener hear the sub portion of the square wave at the same time, or delayed relative to the main speakers?


One would surmise that if audyssey thinks the sub is 2 feet away when it is actually 12 feet away like the mains, then audyssey would delay the sub by 10 feet, causing it to arrive 10 feet too late. Unless the rules of physics are being violated somewhere, it seems like manually correcting the sub distance to 12 feet would give better impulse response.


Has anyone used measurement gear to see how impulse response is affected by less-than-physical sub distances? This should be a fairly straightforward measurement; either the sub distance needs adjustment or it doesn't.

I am one of those people. Just wondering what adjustments, if any, you made to your system to account for the anomaly.


What I eventually did was set my sub phase to ~90 degrees. This made the Audyssey measured distance and the physical distance about the same. It sounds just fine to me, much better than it did before. I don't know if this was a dumb thing to do with the way Audyssey works, but it seemed somewhat "reasonable" as phase delay is basically time delay, and it was the only way I could think of to adjust LFE time delay (= distance) without affecting the frequency component...
 

·
Registered
Joined
·
1,678 Posts

Quote:
Originally Posted by audyssey /forum/post/16223548


No, the filters do not depend on the distance calculation.


There are two kinds of "time" corrections. One is to compensate for the difference in distance between speakers (actually the difference in delay experienced by the signal in each speaker and subwoofer). The second is to identify the time-domain response of the system. This is a signature of how the speaker-room system behaves as time passes. By "time" we mean a number of milliseconds after the direct sound has left the speaker and starts to reflect and interact with the room.


Getting the delays right is critical for imaging as we are very sensitive to variations in time of arrival of sound to each of our ears.


Getting the time domain response right is critical in mitigating the effects of reflections and other room interactions.


But the two are completely independent.


Thanks Chris.


Thinking about it a bit more, of course you're right.


The time of arrival of the impulse is one thing, its contents another.


Analysis of the impulse is timed to its own initial rise and not the delay in arriving


Arrival time can be overridden, as it's independent.


But if arrival time detection is skewed enough by mechanical (or other) distortions enough to be off by the orders of magnitude being discussed (+10'), wouldn't that also infer that the corrections might also be way off due to the unwanted distortions induced?


Would a reasonable guideline be that if a distance is off (especially to short) by a significant margin, that one should re-run the measurement and change some physical aspect of the measurement setup?
 

·
Registered
Joined
·
1,678 Posts
BTW- related to all this discussion of mechanically induced measurement challenges, another AVP and Audyssey Pro user just confirmed that he validated the conjecture.


He had just re-measured his system, and got a 2' sub distance.

Interesting thing is, he was using a mic stand with a boom holding the rubber isolated Audyssey pro mic.

But, he confirms that the stand was touching his couch for the first five positions.


Based on the theory I put out on the mechanical coupling, he re-did his measurements.


After he re-did the measurements ensuring the stand was not touching the furniture, he got a perfect distance reading on all channels and a good EQ result.


Hopefully he'll post is own view on this later. But here's his comment on the AVP thread .


Bottom line, even mic stand and pro users need to be vigilant about minimizing mechanical vibration on the mic.
 

·
Registered
Joined
·
5,153 Posts

Quote:
Originally Posted by pepar /forum/post/16219714


I could not find any comments from you on what you thought of the overall sound - except for the bass - before. What did you think?

- I originally had a Marantz SR-7400 before I upgraded to the Denon 3808ci for HDMI. When I originally switched about 2 years ago, the Denon didn't sound as good with music as the Marantz did. The first time I ran Audyssey, it immediately improved. Everything just sounded cleaner with Audyssey on.


When I ran it again the other day, I didn't notice anything really improving over my original Audyssey calibration other than the bass. I like the sound of Audyssey with music a lot. I don't notice it as much with movies. I'm still undecided on whether I like the standard Audyssey or Audyssey flat better for music.
 

·
Registered
Joined
·
83 Posts

Quote:
Originally Posted by JonFo /forum/post/16221900


For those that want (need?) to try a mic stand with adjustable boom to hold their Audyssey mics over the seating locations to eliminate mechanical coupling issues, here is an example of the components you might need in addition to a basic mic boom.

This topic was covered a bit a year ago, but was spread out, this hopefully condenses it to one post.


The adapter required to take a standard mic boom and support the typical receiver supplied Audyssey mic is as follows:


You need two things, something that attaches to the standard 5/8" fine mic stand/boom arm connection, then enables a 90 degree (adjustable) angle to a "1/4-20" screw. (1/4" and 20 threads per inch).


This can usually be done in two parts, one is the adjustable 90 degree elbow' and the second is the ¼ screw mount.


The adjustable angle component, such as this OSS MSA-9501 POSILOK 4-inch :




The screw mount component is something like this Manfrotto 195 5/8" Stud to 1/4"-20 Screw Adapter, Aluminum - Black :




Under $15 for both + shipping, or find them at your local pro-audio / musicians shop.




Hi JonFo,


What an excellent idea. I know my mic was being affected by vibrations during Audyssey test tones. Using a camera tripod was very awkward as well. The tripod would lean against an end table and that table surely vibrated.


Because of shipping costs to Canada... ($20 for a $3.50 1/4" adapter and $18 for the $12 elbow adapter), I looked around to see if there was another device similar to the one you found. I lucked out. the item below is $14. It cost me about $30 with shipping costs. Free in the US. Here's the link and pic.



http://www.frontendaudio.com/On_Stag...9999-04642.htm


Thanks again for your great idea.


Brock
 

·
Banned
Joined
·
2,323 Posts
Because of shipping costs to Canada... ($20 for a $3.50 1/4" adapter and $18 for the $12 elbow adapter), I looked around to see if there was another device similar to the one you found. I lucked out. the item below is $14. It cost me about $30 with shipping costs. Free in the US. Here's the link and pic.



http://www.frontendaudio.com/On_Stag...9999-04642.htm


Thanks again for your great idea.


Brock[/quote]


Hey Brock,


This is a very nice adaptor (made of gold). It is indeed perfect for the boom attachement. Gorgeous and practical mic holder.


Thanks a lot, great find.


Bob
 
13741 - 13760 of 79637 Posts
Status
Not open for further replies.
Top