Microphone placement?

When calibrating my system with MultEQ, where should the microphone be placed?

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    Audyssey Labs

    Polarity warnings are just warnings.  No need to worry about them if you have checked the wiring. They have no effect on the calculations.  

    Large or Small is not an Audyssey determination.  It comes from NAD.  Audyssey follows their rules.  The roll off is calculated from all measurements combined. So, if you are not placing the mic in the same exact positions every time it is expected to see differences.  In any case, I recommend setting to 70 Hz so that more content is sent to the sub where the Audyssey filters have higher resolution.  The measurements are quite accurate.

    Not sure about Dynamic EQ sounding bass heavy. If the speaker levels are left as calculated it will be calibrated to film levels.

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    Joe

    Microphone Extension:  I have to get a cord longer than 25 feet.  (50ft) - Is it better for me not to calibrate at all with Audyssey than to try to do auto calibration at this distance?  I've read beyond 25 feet causes distortion in high frequencies.  

    Also - can I use a STEREO 3.5mm extender or does it 'have' to be a MONO extender?  

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    Luke

    Hi Joe,

    You could get an extension cord for the mic, but we do not recommend an extension cord over 25 feet, as the mic signal will deminish over long runs, we  recommend this cord; http://www.mcmelectronics.com/product/24-6265

    We recommend the "Mono' cord.

     

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    Joe

    Hi Luke - I understand you don't "recommend" it but does that mean I'm better off with zero audyssey calibration?  It's a weird situation.   Would it be plausible for me to do the calibration with a non recommended solution and then adjust the high frequencies after the fact? 

     

    I guess I'm trying to decide what's worse.  A calibration with a 50ft extension or no calibration at all??

     

    thanks!

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    Luke

    Hi Joe,

    I would recommend moving the AVR into the room, calibrate and move the AVR back.

     

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    Joe

    Luke,

    That's impossible. My speakers are all wired through the walls to my media closet.  I'm simply asking.  What's better - NO Calibration or a non recommended solution such as the extension? Would it be plausible for me to do the calibration with a non recommended solution and then adjust the high frequencies after the fact? 

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    Luke

    Hi Joe,

    We do not have a solution for this, the mic signal will be significantly lower at high frequencies and so the filters will boost more than necessary. So Audyssey will think that your system is seriously lacking in the hi end and boost the Hi end. You will have a very bright sounding system.

    Again, which AVR do you have?

     

    Regards,

    Luke

    Audyssey Laboratories

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    Joe

    I have the Onkyo NR609 -   Knowing that it will tune on the higher end at least gives me a starting point to work from.  Compared to ground zero.  I understand DBs and using my SPL meter but I have no idea how to calibrate EQ.  

     

    Lastly - do I HAVE to use a Mono extension?? I know you have a recommended cord but would a Stereo extension work?? thank so much for your time! 

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    Luke

    I was hoping that you have a AVR with Audyssey MultEQ Pro, you could calibrate with the Audyssey Installer kit with those AVRs, the Audyssey Installer kit comes with 75 foot of mini XLR cables that you could calibrate the system to more 100 feet away with no signal degradation. Audyssey Installer Program: http://www.audyssey.com/installers/installer-program

    The calibration is for the whole audio spectrum, but because the mic signal degrades over long runs and the hi frequency is what dimishes, you will have a overly bright calibration.

    We recommend the mono 3.5MM extension cable.

     

    Regards,

    Luke

    Audyssey Laboratories

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    Joe

    Unfortunately I do not have MultEQ Pro.  I think it's safe for me to calibrate with "bright" results and then tone it down from there.  It  can't hurt. At least I know they will be bright. 

     

    thanks for your help

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    Kingyu

    Dears,

    I setup my home theater in the living room, wide 5.6m between the left and right surround speaker, deep 4.3m between back wall and front wall (screen). Please see the photos attached.

    The sofa (2 seat + 3 seat + 1 seat) is placed about 10cm to the back wall. The back of sofa is about 45cm, the seat is about 55cm. The left seat of 3 seat sofa is the middle (RED LINE). The approximate size is show in the Excel file attached.

    Q1: The 1st position should be middle of the seat (RED 1), or the actual listening place (GREEN 1)?

    Q2: The 2nd and 3rd position should be in the actaul seat (RED 2 & 3, not symmetrical), or between 2-3 ft (1 m) what your recommend (GREEN 2 & 3, both 90cm to RED 1)?

    Q3: The 4,5,6 position should be 50cm before the 1,2,3 symmetry with the seat edge (RED 4,5,6), or 90cm exactly as the distance between 1,2,3 (GREEN 4,5,6)?

    Q4: The 7,8 position should be in the middle of 1,2,3 (RED 7,8), or a little back and >50cm between the back wall (GREEN 7,8)?

    Thanks!

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    Audyssey Labs

    I recommend a tighter measurement pattern to avoid going to far to the sides as shown in the attachment.

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    Kingyu

    Hi Chris,

    I got your point, tighter is better. After reading all comments on this topic, I understand too much than the little information given in the Onkyo and Denon manuals. Audyssey have done a very good job on this, but I am afraid too few users know how to use it better.

    The (3) seat cannot open for foot (photo attached), so it is seldom sit. And most time (about 80%) only one person watch movie and sit on the middle (1). Shall I put the (2), (6) & (7) more closer as shown in the attachment to enhance the effect of (1)?

    And I am trying to buy a Pro Kit to calibrate on 32 positions (still hunger for Luke's help on  http://audyssey.zendesk.com/tickets/5614). Will you please recommend the 32 positions pattern too? 

    Thanks!

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    Audyssey Labs

    Hi,

    The Audyssey algorithm needs to take spaced measurements to collect information from the room.  It doesn't matter how many people will be watching.  Even with one listener, you must follow the same pattern.  

    32 positions are rarely needed.  I would recommend 16 if you get the Pro Kit.  They don't have to be exactly placed, but should be distributed within the area of the 8 measurements we just talked about.  The idea is to sample the listening area at multiple points to give the software more information about the room problems.

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    Kingyu

    Understand. One more question, which one will be better: symmetrical between (1) or just let it be in the listening seat?

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    Audyssey Labs

    In the listening seat

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    Kingyu

    Fully understand! Thank you very much!

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    Tim Catley

    I have a rather smallist home theater. So my primary listening postion, is the sofa, that's up against the back wall. I know that you should avoid putting the microphone near the wall, but that's where I sit. So where should I place the microphone?

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    Audyssey Labs

    Hi Tim, all you have to do is keep the mic about 12-18" away from the wall.  The general pattern shown in the diagram can still be followed with a slight shift forward of all the positions.

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    Joel Locsin

    Hi again Chris.  Been listening to calibrated settings for about a month, but I find BD video concerts somewhat bright, even with the Movie mode (w/c I understand already has roll-off at higher frequencies).  

    As a background, I did calibration with the mic on top of a firm pillow (as I don't have a tripod) on the couch, at ear level w/c is around 5" below the height of the backrest.  I reviewed this thread and read that you recommend I should put the mic slightly above the height of the backrest.  Perhaps I should do this, as the reflection from the backrest might be contributing to the brightness of high frequencies, is this correct?  As a consequence, I have to reduce Tone by -2db or -4db when I watch most concerts.  My room has some treatment, including the rear wall.  Should I perhaps remove the rear wall absorber during calibration so audyssey will adjust for lesser brightness caused by reflections from this rear wall?

    Any other tips on how to reduce this brightness?  Thanks.

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    Joel Locsin

    BTW, how do I see the frequency curves after calibration (using an Onkyo TX-NR809)  I read some posts here mentioning certain 'dB' values at certain frequencies.  Where do I find these?  Perhaps I can see what settings are made to my higher frequencies.  Thanks.

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    Audyssey Labs

    Hi Joel,

    1. It's a very bad idea to use a pillow as a stand.  It absorbs high frequencies near the mic and so the measurements are biased into boosting more than they should

    2. It's also a bad idea to judge the calibration using music content.  There are widely varying standards in music mixing unlike film that follows very strict standards.

    The first thing to do is to use a proper mic stand (cheap camera tripod is fine).  After that, if you feel that some music needs high frequency reduction you will have to do it manually as it is impossible to know the conditions in the music studio.

    Unfortunately Onkyo does not show the Audyssey filters in their display...

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    Joel Locsin

    I understand.  But if I use a relatively cheap, light tripod, wouldn't it have a similar effect as the firm pillow, since the tripod will placed on top of the couch (w/c would have similar firmness as the firm pillow)?  But if I placed the tripod on the floor, that would require moving the couch, w/c is also not recommended.

    Also, I read someone who tried lowering the mic a bit lower than ear level to reduce brightness.  I'm not sure if this is desirable.  Thanks Chris.

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    Audyssey Labs

    The lighter/cheaper the better.  The idea is to not have any large surfaces right next to the mic. The couch is OK, it's not close enough to the mic tip to cause a problem.

    The other thing to make sure is that you are not taking measurements too far off to the sides.  The same thing will happen.  The pattern shown here should be followed.  If the back wall is very close to the back of the couch then measurements 7 and 8 should move forward.

    Lowering the mic typically takes it off the center axis of the speaker and there it will see a high frequency roll off.  That will result in a high frequency boost. 

    Finally, try using the Movie target curve.  We have found that it is the most applicable for most rooms because of the high frequency roll off that better translates the content made in a low reverberation studio.

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    Neilson

    Chris. When you say movie setting, are you referring to the thx movie setting?

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    Audyssey Labs

    No, I am referring to the Audyssey Reference curve that Onkyo now calls Movie.  The Audyssey Flat curve is what Onkyo calls Music.

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    Kingyu

    Dear Chris,

    Continue with the questions above on May 13, I am prepareing for the Pro Kit calibration.

    As you said: 32 positions are rarely needed, I would recommend 16 if you get the Pro Kit.

    Bythe User Guide: This improvement comes with diminishing returns. Measuring more than 8 or 10 positions in a small room rarely improves the quality of the calibration.

    I am a perfectionist. If I am crazy to pursue the perfection, can I measure 32 positions as attached @32.xls file shows:

    1~8  -  as your suggestion on May 15;

    9~12  -  as user guide;

    13~20  -  as your suggestion on May 15, be distributed within the area of the 8 measurements we just talked about;

    21~32  -  as user guide, vary the height of the microphone by a few inches between measurement positions to account for standing waves between the floor and ceiling. So I choose 1/10/3/4/5/13 to measure up and down 3 inches between ear height.

    Am I right to do this, or are there any other method will be more perfect?

    And if only 16 position, will you please show me the 9~16 on @16.xls file?

    Thank you!

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    Audyssey Labs

    Hi Kingyu,

    If you are OK with taking so many measurements, then the 32 pattern you have will work well.  Some small variation in microphone height (as you show) will be good.

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    Pjmurphy2

    Hi Chris,

    In regards to the "mic placement" topic about distances after taking the first measurement you said on Dec. 12,  2009; "The exact distance is not critical. Somewhere between 2-3 ft (1 m) is what we recommend.".  1m=39 inches(roughly), but in almost all subsequent posts you seem to advise a 2 foot distance.

    Have you changed your thinking on this or has MultEQ evolved so much since 2009 that the tighter parameter is now better.  After all, 24 inches is a LOT different than 39 inches.

    I also understand that you always mention that distances (after the 1st placement) are not critical but I would assume when you say that Audyssey recommends 1m, that would be how the product was designed and should give us the most accurate calibration.  Or not?  

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    Pjmurphy2

    Nevermind.

    After rereading, you put the (1m) as a translation for 3ft.  I read it as "...1m is what we suggest." 

    Sorry for wasting your time.

     

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