Microphone placement?

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

Have more questions? Submit a request

208 Comments

  • 0
    Avatar
    Audyssey Labs

    Your explanation was good.  It's a bad idea to have a person near the mic.  The reflections from our body will interfere with proper measurements especially at higher frequencies.

  • 0
    Avatar
    Audyssey Labs

    ajsuperman: you should start the measurements in the row where you sit most often.  Start in the middle of that row and then move to the left and right of middle. Then move to the second row and take 3 measurements making sure you are not too close to the back wall (18" or more distance).  The final 2 measurements should be in the area between the two rows.  All measurements should be at ear height.

  • 0
    Avatar
    Sonny O'Hara

    Hello Chris:

    This is in regards to 8 position calibration of 3808. My room size is 24 by 18 ft and I sit at about 10.5 ft from the centre speaker and 7 feet from the rear wall. For measurements 8 and 9, whish of these would you recommend?

    • 1 foot forward to the front and side *of the main sitting position *

                                             versus

    • 1 foot backward and to the side of the main sitting position.

    Could you please explain why you would recommend one over the other.

    Thanks again.

    Sonny.

     

  • 0
    Avatar
    Audyssey Labs

    Hi Stephan,

    There are varying opinions about this.  Dolby recommends wide spacing and THX recommends very close spacing.  Both make their own arguments.  In my opinion, the importance of the Back Surrounds is highly overstated.  It really won't make much difference how you space them so I recommend doing it based on whatever is easier for your room.

    What really makes the biggest improvement to 5.1 surrounds sound is adding Wide speakers to the front.  Research in psychoacoustics has shown that this is the most important direction for expanding the soundstage.  The second most important is Height speakers up front.  Back Surrounds are a distant third.

    More info here: http://www.audyssey.com/audio-technology/audyssey-dsx

  • 0
    Avatar
    Audyssey Labs

    Hi John: yes it's possible.  Wireless systems add a significant delay to the signal and Audyssey sees that and compensates for it so that all speakers are at the same "distance".

  • 0
    Avatar
    Audyssey Labs

    Hi Roman,

    It's generally better to have matched speakers across the front, wide and/or Height.  Adding two different speakers in the surrounds is no problem.

    The Wides should be at ±60°.  That puts them along the side walls about half way down the room in most cases.  They must be at the same height as the front L, C, R speakers.

  • 0
    Avatar
    Juan Javier Esquivel

    My seat or furniture where I seat are leather.

  • 0
    Avatar
    Alex0925

    Hi Samuel,

    I just wanted to share my experience with you as I am in a very similar situation to yours - also a small bedroom with a listening position on a couch which is practically against the back wall. It's perfectly OK that the mic will be placed ahead of your main listening position even though you wouldn't sit there because the main point is to make sure that you observe the minimum distance of 18' or 50 cm from all the boundaries in your listening area such as back wall, side walls and the back of the couch (if your listening position is on it, as in my case), and since most couches' backs are tilted the minimum distance should apply to the bottom of couch back, not the top, as it is further ahead - so you should measure 18' ahead from that line, and you better use a tripod for the mic as it is very convenient and it prevents mic signal distortion. As long as you observe these minimum distances there won't be any bass dips or peaks - the bass will sound precise as it should. And, yes, it's OK that your surround left and right are pointed to your ears, given the space limitations.

    If you should have any further questions feel free to ask.

     

    Cheers,

    Alex

  • 0
    Avatar
    Chris Joenck

    Chris,

    I have been struggling with a NAD T775 setup all day today. I get polarity warnings and when I re-run the setup, the warning disappears. It seems very random. I also get 0 feet distance detected in the auto setup. Sometimes the center speaker is detected as large, sometimes small - again random. The detected cross-over frequency hovers between 40hs and 70hz. In your experience, how accurate are these measurements.

    Dynamic EQ sounds too bass heavy and dialog is washed out to the point where it is hard to follow dialog.

    Any suggestion is very much appreciated.

  • 0
    Avatar
    Audyssey Labs

    Hi Ram,

    In that case, you should use the recommendations in the diagram.  You should not remove the couch during the measurement.  

  • 0
    Avatar
    Audyssey Labs

    The reason not to measure so close to the wall is that the info reaching the mic in these conditions is different from the info reaching your ears.  The crossover differences reported are very small so I don't think it would be an audible change.  

    No need to warm up the speakers or wait for break in.  There are no measurable effects that would influence the results.

  • 0
    Avatar
    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!

  • 0
    Avatar
    Bhanu

    Wim - Just went through this with my 3311.  After being dissatisfied with the sound for quite some time (but used DynEq), I tried the measurements to be almost in the sweet spot but still little back since my couch was to the wall.    So, in the above case what worked for me was 1 position right in the tip of triangle but a long triangle and then the rest with tripod on the floor in front the couch but mic coming up to the ear level.   I took 6 measurements.   So in summary...if your wall is right behind the couch...do not take any measurements on the couch.

  • 0
    Avatar
    Alex0925

    Hey Chris,

    It's nice to be back, well, one thing just crossed my mind recently: it was my understanding that for equalizer setup Audyssey MultEQ measures the volume of the room, not the space, so, would it be correct to assume that any objects not interfering with setup mic signal flow towards speakers, but still located in the room (e.g. wall mounted shelves and other small sized built-in furniture will still cause errors in equalizer frequency response setup calculations? In other words, for the one and only correct AVR EQ frequency response setup calculation should MultEQ room correction setup be done in absolutely empty room?

     

    Sorry if I didn't make myself quite clear, happy to elaborate on that

    Many thanx in advance,

    Regards,

    Alex

  • 0
    Avatar
    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.

  • 0
    Avatar
    Audyssey Labs

    Hi Rob, it's not a good idea to have the gain all the way up.  The AVR will run out level compensation range.  It shows -12 dB now, but that's all it can do.  Most likely it needs to cut more to bring the sub to reference level.  So, the midway point is more typical and sometimes you have to go even lower than that depending on sub placement.  Any trim value other than ±12 dB is fine.

  • 0
    Avatar
    Owen Heuston

    Hi Chris,

    Why would Audyssey set my Acoustic Research AR2C Center at -6 on my Onkyo SR-608?  It is not too close to any wall or corner. 

  • 0
    Avatar
    Audyssey Labs

    Roddis: yes it's ok to measure with tape for the speakers.  The subwoofer usually has filters in it that add more delay so a tape measurement is not accurate.

  • 0
    Avatar
    Audyssey Labs

    Hi Sonny,

    I would recommend taking the last two measurements (7 and 8) as shown in the diagram above.  This will give MultEQ more information about the area around the main listening position.  

  • 0
    Avatar
    Stephan Leroy Folkes

    Hi,

    this is not really the exact thread to ask this question but here goes. I have a Samsung HT-C6930W home theater system and was wanting to mount the back rear speakers. According to the booklet, it states that the speakers should be 70cm to 1m away from the listening position. I want to mount from (they're currently on stands) on the back wall but it would be about 1.2m to 1.5m distance away. To compensate the distance would it be best to set the delays and/or increase the db to make up for the longer distance? Or should I do what was recommended in the booklet? Thanks

  • 0
    Avatar
    Audyssey Labs

    Hi Bhanu,

    I don't fully understand the comments.  "Too bright" and "cut off" seem opposite to each other.  In any case, the best setups have the tweeters at the same level as the ears.  If the tweeters are not at ear level then the mic height should most likely be at ear level.  With some troublesome (e.g. ribbon) tweeters some experimentation is needed to make sure the mic is not in a null of their directivity pattern.

    Tweeters are very directional.  As you move off their center axis their energy starts to diminish.  If you measure there the software will think there is not enough high frequency content and overcompensate.  That's why it's generally best to point the speakers to the listener.  This is true even if you don't have room correction.  The speakers are designed to give their best performance on-axis.

  • 0
    Avatar
    Roman Smolkin

    Hi, I just got a new receiver with Audyssey XT and I'm really excited to set it up tonight.  My living room is not big and my couch is somewhat oddly shaped.  Basically where I sit over 90% of the time is not the center, but to the right of the TV.  The right rear speaker is actually like 1 foot from my ear.  So to make the system sound the best where I usually sit, do I start with the mic there and then go in like a clockwise order with the other positions?  The wall with windows is actually right behind the couch so can't really go back there.  Or should I start more like in the center of the room, or still in the center of the couch?  I never really sit in the center though, sometimes if I have a guest they might sit there, but still closer to the right.  Thanks!

  • 0
    Avatar
    Audyssey Labs

    Hello Juan,

    The mic should be placed as close as possible to ear height.  If the back of the couch is high then reflections could affect the measurements if the mic is placed too close to it.  You can raise the mic a few cm to make sure it is just above the seat back or just keep the mic at ear height and move it forward so that it is not too close to the seat back.

    The measurements are designed to collect information about the response of your speakers in the room.  It's best to avoid placing the mic in extreme off axis positions because that can give it misleading information about the off axis response of your speakers.

    The first position should be in the center of the listening area.  Usually, that is where the main seat is.  If the seat is off to the side, we still recommend taking the first measurement in the center.

  • 0
    Avatar
    Alex0925

    You're welcome, Samuel, and one more thing: please, also make sure that there is at least 2 feet distance between your measurement positions, no matter if you take 3 or 6 measurements, otherwise Audyssey will take incorrect space measurements, and also, as already mentioned above, please, make sure that the mic is placed exactly at ear height.

    Regards,

    Alex

  • 0
    Avatar
    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.

     

  • 0
    Avatar
    Matt Butler

    Chris,

    I ran the setup multiple times and find that although the settings seem fine, fronts are about -2 each and the rears are about -5 each, my blu ray films have most of the main sound coming from the rears. This seems strange since i am used to them being in the front with the rears shadowing them instead of vice versa. I am on a Denon receiver.

  • 0
    Avatar
    Dag Johnsen

    Hi Chris,

     

    when measuring the stereo (2 channel) before and after XT32 PRO calibration with REW,

    should we place the microphone in sweetspot and run a sweep, or measure left and right separately and average them after? Do you reccomend 1/6 smoothing or 1/24 to judge the results properly.

     

    Very happy with my Denon A100 / Audyssey XT32 !!

  • 0
    Avatar
    Audyssey Labs

    In the listening seat

  • 0
    Avatar
    Dag Johnsen

    I am using a Denon A100 with XT32 in a stereo setup including subwoofers. Pro Kit.

    I was wondering, would it be better to point the microphone towards the speakers instead of pointing straight up, since I only want to measure those two front speakers and do not need to consider sound from rear speakers?

    I measure a difference in the treble of approxemately 3 dB when pointing the microphone in an angle of 15 degrees towards the center between the front speakers compared to straight up in sweetspot.

     

    Dag Johnsen :-)

     

  • 0
    Avatar
    Audyssey Labs

    Hi Alex,

    The purpose of measuring is to find out what the room is doing when you are listening.  So, it should definitely not be empty!  If there is a problem from shelves or other things in the room the measurement needs to know about it.  Otherwise it will correct for conditions different than what will be there during listening and that would not be very useful...

Article is closed for comments.