"Official" Audyssey thread (FAQ in post #1) - Page 1836

Quote:

Originally Posted by htwaits 

Too true!
My thanks to you and jdsmoothie for the good advice. Now that I have the recommended extension cable, I think it will be quiet enough to run Audyssey later today.

Good luck. Be sure to let us know how you got on!

Quote:

Originally Posted by legierk 

Haven't posted in ages......re-ran Audyssey yesterday on my 4311 with 11.2 because I moved the subs a little and pulled the center out away from the wall a little. Had to level match the subs which I thought was odd seeing as how the original calibration was still valid (in use is a better term I suppose). At any rate, I ended up having to raise the levels of both all the way up to reach 75db. Then, after calibration, it had both at -12db. Weird. I will say I did the calibration with the PJ and HTPC running which caused some ambient fan noise. My logic was that those pieces are always running when I'm in the theater anyway, so why exclude them from the calibration? Put another way, shouldn't I calibrate using "real world" conditions?
In fact, all the levels were below 0db, the front height speakers with the least cut...about -3db. Weird again. I did measure in a tight area, BTW. Figured that since I only have guest over sitting in the back row once in a blue moon, why bother with placing the mic there? I just ran 8 positions centered on the two primary listening postions.
The sound is fine, but I thought the results were ....well, weird. Any suggestions?

How did you 'level match' the subs and what do you use to measure the 75dB?

A calibration where the subs are at -12dB is no good. You will need to lower the gain on the subs and recalibrate. You should be aiming for a trim between -3dB and +3dB for the subs.

The fans in your PJ and HTPC are irrelevant. If Audyssey detects that the ambient noise is too high for a successful calibration, it warns you. No warning means the calibration was good (in the respect of ambient noise anyway).

8 mic positions around the two MLPs are fine, so long as you followed proper practice, as detailed in the Setup Guide and the FAQ.

Quote:

Originally Posted by jmschnur 

Do the cal in as quiet a room as possible . More accurate due to increased signal to noise . I think this is in set up guide.
J

It's a good idea - but Audyssey will not allow a calibration if ambient noise is too high. It raises the level of the chirps up to three times and then gives up if that still does not overcome ambient noise. If th user gets no ambient noise warning, the calibration will be a good one.

Quote:

Originally Posted by htwaits 

The results from the first attempt seem to be good. It turns out that by shoving my head even further down behind the sub, I discovered that out sub does have three phase settings. 180, 90 and 0 degrees. It also turned out that due to the sub's replaced amp having crossed wiring, using 180 degrees was the correct phase setting.
The opening to "Fellowship of the Ring" where the ring finger gets lopped off of the dark lord still has the same satisfying low LFE that it had with our custom calibrated Denon 3806. The 3312CI also sounds good playing portions of two classical SACD recordings with some substantial low notes. Mission complete.
Thanks for all the help.

Great stuff. Glad you are happy with the result!

Quote:

Originally Posted by AustinJerry 


I tend to agree with JM and Feri on this one. While I know that Audyssey detects extreme ambient noise and gives an error, how can we say that ambient noises somewhere between dead quiet and "extreme" won't have some sort of an impact on the calibration? It really isn't all that much extra trouble to turn off the HVAC, refrigerator, ceiling fan, etc. during a calibration. If there is even the slightest chance ambient noise could affect a calibration, why not err on the safe side?

It does no harm to go around turning everything off and running the cal at 3am - but Audyssey already took care of the ambient noise problem in the design of the product - hence the warning if ambient noise is too high for a successful calibration. The implication is that if there is no warning then the calibration is not adversely affected by any ambient noise.

I think turning off the fridge and duct-taping the cat is just another manifestation of the OCD behaviour that characterises the long-term users of this thread (me included). It's in the same catagory as measuring the space between the mic positions to the millimeter - not in any way necessary but it appeals to our inner devils :)

But it's good to see Feri disagreeing with Chris and Audyssey's design - LOL!!

Quote:

Originally Posted by kbarnes701 

I think turning off the fridge and duct-taping the cat is just another manifestation of the OCD behaviour that characterises the long-term users of this thread (me included). It's in the same catagory as measuring the space between the mic positions to the millimeter - not in any way necessary but it appeals to our inner devils :)

 

But it's good to see Feri disagreeing with Chris and Audyssey's design - LOL!!

Regarding the OCD, guilty as charged.  However, there is some reasoning behind my position.  Kindly refer to the attached PDF, which I created a while back, which shows the Pro instructions (a cut-and-paste directly from the app).  I have highlighted a section in yellow, which seems to support Feri's position as well as my own.

I believe it was Chris who has mentioned that one need not strive for absolute quiet during a calibration.  It's strange that we now must choose between Chris' advice, and the Pro instructions.  Regardless, I don't think we need to go to extremes--simply make reasonable efforts to have a quiet environment during a calibration.

Edit: Note to SoundofMind--perhaps the Pro instructions should be placed in post #2 of the Pro thread?

Quote:

Originally Posted by holt7153 


Interesting...I assumed it was possible to get an inaccurate reading due to a car horn or barking dog without receiving the "ambient noise" warning. Good to know .

That is actually a very good point. I guess it depends on how the ambient noise detection in Audyssey works. If it 'listens' to the background noise then, if it finds it too high, it will give the warning. Your point addresses the situation where the background noise is low, but then there is a sudden loud transient noise during the measuring phase of the calibration. In those circumstances, does the ambient noise detection kick in?  I assume it does because a car horn or a dog barking will not sound, to Audyssey, like the test tone/chirp. If I remember, I will Ask Audyssey so we get a definitive answer.

Quote:

Originally Posted by AustinJerry 

 

Regarding the OCD, guilty as charged.  However, there is some reasoning behind my position.  Kindly refer to the attached PDF, which I created a while back, which shows the Pro instructions (a cut-and-paste directly from the app).  I have highlighted a section in yellow, which seems to support Feri's position as well as my own.

 

 

 

Pro Instructions.pdf 280k .pdf file

 

 

 

I believe it was Chris who has mentioned that one need not strive for absolute quiet during a calibration.  It's strange that we now must choose between Chris' advice, and the Pro instructions.  Regardless, I don't think we need to go to extremes--simply make reasonable efforts to have a quiet environment during a calibration.

 

 

Edit: Note to SoundofMind--perhaps the Pro instructions should be placed in post #2 of the Pro thread?

I agree that one should try to get the room quiet before starting the calibration. Where I diverge is to what degree of quiet is needed. The ambient noise detection in Audyssey is there for a reason and while I never go to the lengths of turning off fridges etc, I have never seen the warning. I live deep in the rural countryside of England so there is no ambient noise from traffic etc but the background noise here is about 45 dB during the day (tested with two meters on A weighting). It will be quieter at night but I invariably calibrate during the day when I have the house to myself (Mrs K, being 24 years younger than I am, still goes out to work).

The one time I aborted a calibration was when a huge combine harvester went past my house during one of the measurements and, although no ambient warning message came up, I aborted because I thought the large bass content of the machine's noise might have an adverse effect on the measurement. But I suspect that is the OCD kicking in :)

So I agree with you Jerry - no need to go to extremes but make a reasonable effort to have a quiet room.

Kbarnes, are you sure your ambiant noise level is around 45 dBA?

i've checked in my house a few times (before running Audyssey), including just now, and my noise levels hover around 28 dBA;

i live in a residential part of a small town where there are "commercial streets" about a quarter mile away.

Quote:

Originally Posted by Gellidius 

Kbarnes, are you sure your ambiant noise level is around 45 dBA?

 

i've checked in my house a few times (before running Audyssey), including just now, and my noise levels hover around 28 dBA;

i live in a residential part of a small town where there are "commercial streets" about a quarter mile away.

That is what my SPL meters both read at when the house is quiet. I can't ever recall seeing it anywhere near as low as 28dB. It's odd then because I live in a tiny village surrounded by countryside. There are no industrial type units for miles and the nearest road carrying normal traffic is at least 4 miles away. The small lanes in and around the village carry hardly any traffic at all at any time of the day or night. I'd say one car per hour is the most I'd expect. At certain times of the year - eg harvest - there is more farm traffic but even then it is fairly rare.

It seems unlikely that two different meters, of two different makes, would both give a false reading - but you have made me think. I will also try the SPL meter of my OmniMic s/w next time I get it out and see what that reads at. 28dB seems extraordinarily low to me.

EDIT: I just checked again, with both meters (one is analogue, one digital). 43/44dB. My house is double-glazed and well insulated (thermally). I closed all doors and windows for the test. Local time here is 14:09 and there is no passing traffic, children are at school, no animal noise etc.  We have no HVAC and there is nothing running in the background AFAIK that would generate any appreciable noise. There is no equipment in the listening room, so no fans etc.

I will check again at midnight and see if it is quieter then.

i just took some more readings after checking my meter's calibration: 26 dBA and 52 dBC

readings taken at the MLP.

Quote:

Originally Posted by Gellidius 

i just took some more readings after checking my meter's calibration: 26 dBA and 52 dBC

readings taken at the MLP.

Ah - silly me. I am getting 45dB with the C weighting. My meters are not sensitive enough to give any reading with the A weighting and read LO for the digital meter and hits the stop for the analogue. Seems like we are back on the same page. I'd expect your 52dBC reading corresponds well with my 45dBC reading, given the environmental differences between us. I'll try the OmniMic with the A weighting as it may have the extra sensitivity to give an A reading. 

Quote:

Originally Posted by ccotenj 

^^^
that would make more sense... i wouldn't be surprised to see the a-weighted measurement be significantly lower than the c-weighting, as most (if not all) "ambient noise" would be relatively low in frequency... i'd actually be very surprised if you measured otherwise...

Yes - we are back on the same page now. I may have mistakenly said earlier that my 45dB was with A weighting. If so, my bad.