Subwoofer setup and MultEQ

Many powered subwoofers have controls that are set manually.  It's important to follow some simple guidelines to avoid having these controls interfere with proper subwoofer calibration and integration with the satellite speakers.

  1. If the subwoofer provides a direct input (sometimes called LFE input) then it should always be used.  That input bypasses the filters in the subwoofer and allows the bass management system in the AV Receiver to operate properly
  2. If there is no direct input, then the lowpass filter knob on the subwoofer should be permanently set to the highest frequency it allows.  That way it will not interfere with the MultEQ measurements and bass management
  3. The level control on the subwoofer is often set too high.  This can cause the AV Receiver to run out of level correction range when MultEQ tries to set the subwoofer to reference level.  Set the subwoofer level control to the midpoint.  If MultEQ reports high negative trims (e.g., –12 dB) for the subwoofer, then you should turn the level control further down and run MultEQ again
  4. If there is a Phase control on the sub it should be set to 0°

If you have a subwoofer with room EQ, then you should run that first in the subwoofer and then run MultEQ in the AVR

If you have an external subwoofer processor (such as the SVS AS-EQ1 or the Audyssey Sub Equalizer) you should run the calibration in that processor first and then run MultEQ in your AVR

If you have two subwoofers, there are some additional steps to take:
  1. Place them at equal distances from the main listening position
  2. Set the level controls on the back so they both play at the same level
  3. Connect a y-cord to the sub out of the AVR and then connect to both subs
  4. Turn off processing in the subs as it will not be able to give you the same resolution that you will get from MultEQ (thousands of points vs. a few parametric bands)
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399 Comments

  • 0
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    Audyssey Labs

    Hi William,

    The LFE signal and the bass management crossover are two different things.

    The crossover is responsible for taking the bass from the speakers and sending it to the subwoofer.  That should be set at around the frequency where your speakers are no longer able to reproduce bass.  This is called the crossover frequency.

    In 5.1 content, there is an additional bass-only track called the LFE track.  This is not played from the main speakers, but only from the subwoofer.  This track is authored to have content up to 120 Hz and so the filter in the AVR called LFE Lowpass should be set to 120 Hz. Always.  It is a mistake for AVR makers to even make this an option as it has nothing to do with bass management.

    The fact that Audyssey is setting your sub to –15 dB means that you have the volume on it turned up WAY too high.  Audyssey is trying to set your speaker to studio reference and the AVR is running out of range.  You need to turn down the sub volume and run Audyssey again until the number is higher than –15 dB.  Any other value is fine.

    After that, if you are not interested in Reference and have your own preference then you can turn up the sub level in the AVR.

  • 0
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    William Merritt

    Thanks for the response, Chris.

    So, to make sure that I understand... the LFE track will be sent to the subwoofer ONLY, so I don't have to worry about losing any of it by setting the Crossover setting in my AVR down to 80.  This Crossover is just for the redirection of the bass below that level from my other 5 speakers.... All correct?

    So, my Sub's volume setting is still TOO high for the correct reference level, even though I have it turned down to 30%... I need to turn the volume down further on the sub until I get a setting of say -10 dB or higher.  Correct?

    Do I lose anything from the sub by running it with the sub's volume setting down so low all the time?  

    Thanks again. 

  • 0
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    Kingyu

    Hi William, maybe you need to change the Sub's position. The AVR "hear" your Sub's volume too high, maybe because the volume include too much standing wave that Audyssey cannot correct.

    About the Sub's placement, please see:

    http://www.audioholics.com/tweaks/speaker-setup-guidelines/subwoofer-placement-guidelines

    http://velodyne.com/blog/5-tips-for-optimal-subwoofer-placement/

  • 0
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    Kingyu

    Dear Chris,

    There are no electrical hum at 60 Hz. I think the problem is Sub's placement.

    I changed the Sub's position and ran the MultEQ simply (only 3 position), and got the different results (see the attached graph and Excel file).

    1st position on 2012-8-11, close to wall (10cm), a little close to Left speaker (40cm). The correction graph is perfect flat from 20~120Hz. By hearing, the bass is boomy or muddy, and you can tell the bass direction (bass come from Sub).

    2st position on 2012-9-15, away from wall (60cm), away from Left speaker (50cm). As you told, there is a big mode at 60 Hz. Beside this, still flat to 120Hz. By hearing, the bass is lightly and weakly. And still can tell the bass direction.

    3rd position on 2012-9-20, move to the corner. The correction drop from 80Hz. By hearing, the bass is too strong with boomy or muddy. The bass direction is less, but still can tell maybe because it is too far away :)

    4th position on 2012-9-21, take the middle of 1st and 2nd, 35cm from wall, 55cm from Left speaker. The graph show down at 100Hz, and up at 110Hz, and drop down. By hearing, I think that is more accurate bass. And cannot tell the bass direction, the Sub seams disappear. Is that HIFI enthusiasts said the best bass?

    Q1: Best cruve is 1st position, but best hearing is 4th. What can I do? Are there any perfect position with best cruve and hearing?

    Q2: If choose the 4th position, will Audyssey and AVR transfer some 100~120Hz to other speakers to "help" LFE flat to 120Hz?

    Thank you very much!

  • 0
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    Audyssey Labs

    Hi Kingyu,

    You should go with "best hearing".  The curve difference between position 1 and 4 is not very significant except for a small dip at 100 Hz.  Remember, the graphs are smoothed and are for illustration only so I would not worry about that small dip if it sounds best in that position.  

  • 0
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    Kingyu

    Dear Chris, thank you very much for the fast reply. I got your point, no need to confuse about that small dip :-)

    To confirm mic placement: I remember seen "The order of the measurements after the first one does not matter" before. Does it means I can test from 1~12 mic position show in "How to MultEQ", also can test by 1, 3, 9, 10, 2, 4, 5, 6, 11, 7, 8, 12 so need not to change the mic tripple too much.

  • 0
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    Audyssey Labs

    Yes, that's right. As long as mic position 1 is in the main listening seat, the order after that makes no difference.

  • 0
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    William Merritt

    Thanks, Kingyu, for the links...   I have adjusted the position a bit further from the corner and have decreased the sub's volume down to about 25%.  I ran the Audyssey 2EQ again and got a -11 dB result, so I'm gonna stick with it.  Does sound cleaner now, so it's working.  Thanks to you both.

  • 0
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    Audyssey Labs

    @William: That's right.  The crossover setting has nothing to do with the LFE track and its own separate LFE Lowpass filter.  The crossover's only job is to send low frequency content from the satellite speakers to the sub.  That content is then added to the separate LFE track (if it exists).

    As long as the sub reported level setting is not –12 dB you are fine and within range of the AVR.  You don't lose anything.  The point of level calibration is to set the levels to match the other speakers and to be at reference when you turn the volume on the AVR to 0 dB.

  • 0
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    William Merritt

    Excellent - much appreciated, Chris.  My system is sounding great!

  • 0
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    michalis

    hi Chris,

    is the xt32 capable of correcting the frequencies below 20 hz and which is the limit?

  • 0
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    Audyssey Labs

    It corrects down to 10 Hz if it finds the response to extend that low.

  • 0
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    michalis

    ευχαριστω chris,

    and something else...

    my system has 2 subwoofers , one at the front and one at the left side.

    the subwoofer that  is located at the left from my seat, i can locate some sounds above 70hz and i don't like this.

    i am thinking of using an LPF at 70hz. do you think that will mess the audyssey calibration?

    my receiver is the denon 4311.

    i must first use the LPF and after the audyssey calibration or the opposite?

    thank you,

    Michalis

     

  • 0
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    Audyssey Labs

    Hi Michali,

    The Denon bass management is already applying an LPF at whatever frequency the crossovers are for each speaker.  Adding another LPF will have unknown (probably bad) effects on the phase of the blended speaker-satellite response. 

  • 0
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    seb

    Hi,

    I own an Onkyo 5509 with two subs. Each time I run a calibration, I got the message "Error" for the two subs.

    I've read somewhere that Audyssey cannot calibrate subs which have two loudspeakers ? My subs are Cabasse Etna 2 which have 2 loudspeakers.

    Can you confirm and provide me with an alternate solution ?

    Thank You

    Best Regards

     

    Seb

  • 0
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    Audyssey Labs

    Hi Seb,

    Not sure I understand the problem.  Audyssey can calibrate any sub. It doesn't matter how many drivers it has.  What is the exact error you are getting?  

  • 0
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    seb

    Hi Chris,

    I've launched a calibration and it reconagizes all my speakers but the subs. I've run it several time and always get the same results. The Audyssey generates noises that can be heard on both subs but at the end I still get "error" weither I chose a simple or a complete calibration. Can it be related to the position of the subs ? There are around 2 meters between the two subs and are both on the left side of the room.

    Are there prerequisites before a calibration ? (apart from connecting the speakers ! ;-)

    Any help is welcome.

    Thanks

    Seb

  • 0
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    Audyssey Labs

    Hi Seb,

    This could be because the sub volume is turned up way too high.  That would cause the response to clip the microphone signal and produce an unusable measurement.  Can you turn the sub volume well below the half way point and try?

  • 0
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    seb

    You are probably right as it goes beyond 90 dB when the volume check is made. 

    The problem is that I have absolutely no possibility to setup the volume. They are connected to an amp and then directly to the Onkyo. As far as I understand there is no way during the calibration to modify the volume.

  • 0
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    Audyssey Labs

    Yes, that is definitely the problem. You will need to turn down the sub volume (perhaps a different amp with a volume control?) in order to set up your system correctly.

  • 0
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    seb

    Thanks for you help Chris. 

    I will try with a different amp.

  • 0
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    Marcus Freese

    Hello there,

    i (more or less) read through all the comments but still like to ask some specific questions regarding my problem.

    I have a 5.2 setup with a Denon 2113 AVR and this speakers: http://www.teufel.de/heimkino/theater-4-hybrid-5.2-set-p336.html

    The front speakers both have an integrated active 250mm subwoofer at the side and a bass reflex tube at the back . The subwoofer options of the speakers are on/off (obviously), bass level -3db/+3db and mode AV-Receiver/Stereo Amp.

    I've set it to AV-Receiver and -3db. However, after taking the measurements, the trim setting is always adjusted to -12db. Also, the bass doesn't sound clean and dry during bass heavy scenes. The whole room just seems to vibrate unevenly. The crossover frequencies were automatically set to 80Hz, 40Hz, 40Hz for front, center and surround respectively. I left the LFE freq at 120Hz.

    The front speakers (subwoofers) are standing relatively close to the wall, may that cause undesired reflections from the bass tubes? Also, with the subwoofer chassis on the sides of the front speakers, i can place them either pointing inwards to the TV or outwards to the outer walls of the room (about 1-2m speaker to wall distance). What would you recommend? I haven't tried it pointing inwards yet, but will tomorrow. Maybe i should only use one of the two front speaker subwoofers?

    Another thing (but probably not really related) is, that I am a bit irritated by the 40Hz crossover freq for the surrounds. Shouldn't that value be higher, because those aren't supposed to output frequencies that low?

    Thanks for any feedback in advance!

    Marcus

  • 0
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    Audyssey Labs

    Hi Marcus,

    Do your subwoofers have a line level connection? If so you should use that and not a speaker connection.  That way you can connect them to the Sub Out of the Denon and they will be treated as true subwoofers.  If your AVR only has one Sub Out, then you should use a y-cord to connect to both subwoofers.

    If the level is being set to –12 dB after measurement, then the volume is turned up way too high on the subwoofers.  Audyssey is trying to set the subs to reference level and to match the other speakers and the AVR is running out of range because the subwoofer level is too high.  You should turn it down and run the calibration again to avoid the –12 dB issue.

    Pointing of subwoofers makes no difference because the wavelengths are vey large at those frequencies and they are not directional.

    No need to be irritated.  Audyssey is measuring the performance of the surround speakers. It has nothing to do with the content.  If the speakers are very close to the wall then their bass response will be lower.  There is no need to worry about this.  If you feel that you want the speakers to cross over at a higher frequency you can move the crossover up.

  • 0
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    Santo Budi

    Hi, Chris

    Regarding the subs input chanel there are 1 LFE input & 1 pair L/R input. Are there any big difference for subwoofer performance if connecting subwoofer using LFE input to Receiver's LFE output rather than using subwoofer L/R input?

    I know that we have to turn the sub crossover freq to the max point when using L/R input.

    Thanks Chris. 

  • 0
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    Audyssey Labs

    Hi Santo,

    The LFE input on the sub doesn't have any filters applied and so that is the best choice when connecting to an AVR.  The filters for bass management should be applied only in the AVR and not in the sub.

  • 0
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    Santo Budi

    So we can say that the 1st priority to choose the best subwoofer is the one that has the LFE input, is it right ?                                                                                                  How about the others that doesn't have the LFE input, is the bass performance far below than we've expect, cause I've found some branded subwoofer have no LFE input, only L/R input.

    Thanks Chris. 

  • 0
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    Audyssey Labs

    The best subwoofer is the one that produces the lowest bass extension! Having an LFE input is good, but you can always use the standard inputs and set their filter knob to the highest frequency it allows (to avoid interference with proper bass management).

  • 0
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    Santo Budi

    You mean by setting the filter knob to the highest frequency is like to disable the sub doing the bass management. So is this similar using the LFE input compare with using the standard inputs, in other words using one of those 2 inputs doesn't effect the bass output.  That's why you said the best subwoofer is the one that produces the lowest bass extension!

    Thanks Chris. 

  • 0
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    Santo Budi

    Hi Chris,

    I read your post " The Audyssey Reference and Audyssey Flat curves are identical in the low frequency range. They only difference is in the high frequencies where the Ref. curve has a roll off".

    My question is,  Audyssey Reference and Audyssey Flat curves have a same bass effect but which one has more treble effect (more high freq).

    Thanks Chris. 

  • 0
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    Audyssey Labs

    Hi Santo, the target curves are not intended to produce more bass or more treble.  They are used to shape the response of each speaker in your room.  So, the amount of bass or treble correction they will produce depends on the problems the speaker is having in the room.  The curves are trying to make the bass response flat with no bumps. At the high frequencies the Ref curve is shaping the speaker response to have a slight roll off, while the Flat curve is shaping the response to be flat.  Typically, that means that the Flat curve will sound brighter (more treble).

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