MultEQ Target Curves

What frequency response target is optimal?

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    Chris Kyriakakis

    Contrary to popular belief, a target curve that is flat from 20 Hz to 20 kHz is not always the one that will produce the correct sound. There are several reasons for this including the fact that loudspeakers are much more directional at high frequencies than they are at low frequencies. This means that the balance of direct and room sound is very different at the high and low ends of the frequency spectrum.

    The Audyssey Reference target curve setting (also called Movie in some products) makes the appropriate correction at high frequencies to alleviate this problem. A slight roll-off is introduced that restores the balance between direct and reflected sound.

    The Audyssey Flat setting (also called Music in some products) uses the MultEQ filters in the same way as the Audyssey curve, but it does not apply a high frequency roll-off. This setting is appropriate for very small or highly treated rooms in which the listener is seated quite close to the loudspeakers. It is also recommended for all rooms when the receiver is in THX processing mode. This allows THX re-equalization to operate exactly as it was intended.

    Some manufacturers have decided to implement a Bypass L/R (or Front) setting.  This uses the MultEQ filters that were calculated for the entire listening area, but it does not apply any filtering to the front left and right loudspeakers. The average measured response from the front left and right loudspeakers is used as the target curve for the remaining loudspeakers in the system. The subwoofer in this case is equalized to flat as is the case for all the settings described above.  This is not a setting recommended by Audyssey.

    In some products, there is a Manual EQ setting. This is a traditional parametric equalizer that does not use the MultEQ filters or the Audyssey measurement process at all.

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    Hemal

    Hi Chris,

     

    What target curve should be used when playing music?  I'm using a Denon 2310, KEF3005SE and B&W PV1 in a small room.

     

    Thanks in advance,

     

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    Chris Kyriakakis

    Hi,

    There is no standard music target curve as there is for film content.  We recommend starting with the Audyssey curve, but also trying the Flat curve.  In a small room Flat could work better for some types of music.

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    Andy C

    Hi Chris,

    Let's assume for the sake of argument that Audyssey Flat were chosen as the target curve.  I'm interested in the high-frequency behavior of the Audyssey EQ.  Does this mean that the quasi-anechoic response (obtained from the windowed impulse response) would be made flat at high frequencies (well above Schroeder), or is it the steady-state response that's made flat, or something else?  I've used EQ methods that flatten the steady-state response at all frequencies, and they sounded very bright to me.

    Also, I assume that in the bass, steady-state must be used because of the low-frequency limitations of impulse response windowing and the need to take into account room modes.

    I'm asking these questions because it seems to me that the need for low-frequency EQ for subwoofers and such is self-evident, but also that the best way to do EQ at higher frequencies is somewhat more a matter of interpretation than it is at low frequencies.

    Thanks!

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    Andy C

    A second question:  Does Audyssey Flat use Midrange Compensation as described in your notes elsewhere in this section?

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    Chris Kyriakakis

    Hi Andy,

    Audyssey uses a nonlinear weighting method to combine the measurements in your room in order to determine the response.  You are correct in saying that simply flattening the steady state response results in sound that is too bright.  There are acoustical and perceptual reasons for that.  Our research has shown that the EQ is needed over the entire range.  The weighting of lower frequencies, however, is important and that is part of the algorithm.

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    pepar

    I have had some success in adding some needed "air" to my system by tweaking the target curve.  In re the Audyssey Reference Curve, I have a 12k handle at .5dB and one locking 24k at 0dB, and a +2dB handle at 20k.  I have listened to 2-ch CDs, hi-res multichannel, concert Blu-rays and action movies with these tweaks and I think it is an improvement over what I had before.  

    I'd like to lock 13k-14k at whatever it is now and try lifting 20k by another .5dB, but I don't know how far above Reference it is now at 13k-14k.  Is there a way for me to determine that?

    Thanks, Jeff 

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    Chris Kyriakakis

    Are you starting from the High Frequency Roll Off 1 (also known as Audyssey Reference) curve?  If so, 13 kHz is down about 3 dB from flat

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    pepar

    Yes, Chris, thanks .. I am starting with HF Roll Off 1. 

    I worked through it by trial and error. I maximized the Curve Editor screen and captured it.  Then I edited the curve in a spreadsheet to have an additional .5dB boost at 20k and a handle at 14k, saved it, loaded it, captured it and alt|tabbed between the two JPEGs. I repeated the editing (the 14k handle), loading, etc, steps until the 14k points on the +2.25dB/20k curve and the +2dB/20k curve matched. Hope that makes sense. :)

    What I've got now is 10k/0dB, 12k/.25dB, 14k/.7dB, 20k/2.25dB and 24k/0dB.  +2.5dB at 20k was too brittle, so I backed it off a bit. I am amazed at how much difference a 1/4 db makes at the higher frequencies.

    Jeff

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    Rickard L

    Hi, I see in the manual for the new Onkyo TX-NR1009 that there are two target choices: Movies and Music.

    Has Onkyo *finally* implemented an explicit "flat" target choice or is Music something else than a flat target?

    from page 53:

    Movie: Select this setting for movie material. The Audyssey indicator lights.

    Music: Select this setting for music material. The Audyssey indicator lights.

     

    Thanks,

    Rickard

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    Chris Kyriakakis

    Hi Rickard, yes that is correct.  You can now select the curve manually.

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    pepar

    Would that be fixed offsets to the curve that apply equally even if there is a Pro-customized target curve being used?

     

    Jeff

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    Chris Kyriakakis

    Jeff, I'm not sure I understand the context of the question...

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    pepar

    Sorry, Chris.  If an edited target curve has been loaded from MultEQ Pro, does the "Music" setting offset the custom curve by the same amount that it would the Audyssey Reference curve?  IIRC, when this came up with Denon, the answer was yes.

    Jeff

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    Chris Kyriakakis

    Ah. Got it. The amount of offset (in dB) that you apply in your edited curve will be applied to the selected target curve.  

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    pepar

    Thanks!

    Jeff

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    Mark van de Vries

    Hello,

    I am using a Marantz SR5003 with B&W 685, 686, HTM62 and a BK XXLS400 sub in a small untreated room. My back speakers are 1.5 cm from the wall thus I need to equalize the setup. Now I have run Audyssey 6 times with the microphone at the listening position and have been using the Audyssey flat setting for over a month.    Today decided to do a comparison using only stereo music with the equalizer off vs Audyssey Flat for the front speakers and liked it best with the equalizer off (a bit too bright with the equalizer on). Thus decided to go with the Audyssey Front setting so as to adjust all the other speakers to the front speakers characteristics. To my surprise however this setting only deviates from the Flat setting by +2 dB in the 16k band for all speakers. Why is this? Another thing I noted was that for the Audyssey Flat setting the FR and FL speakers were equalized with a graph that was basically a slightly inclined line (higher towards the higher frequencies) with only a few dips with a mean of +3 dB for all the bands combined. (I indeed noted on pans that my FR and FL speakers were less loud than the rest). Would my problems be fixed if I were to just to detract -3 dB for the C, SR and SL speakers and go with the Front setting?

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    robert Carman

    Hey Chris,

    I have just recently treated my Room with Auralex studio foam wedges/bass traps (absorbition) and (metro diffusors) and was trying to decide witch curve sounds best since I treated the room. I noticed the Audyssey curve seems to have more tighter bass than the flat curve.....am I hearing things or is this True? I used to like the flat curve because I felt the Audyssey curve was a bit lacking in the high frequency detail (Like when glass is breaking). You stated above that a flat curve would be best for a highly treated room and for someone who sits close to the loud speakers....my speakers are 12 Ft from MLP and below are pics of my room if you can tell me if this classifies as a highly treated room. I have a 9.1 DSX system.

     

    Thanks Chris!!

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    Chris Kyriakakis

    Hi Mark,

    The Front Bypass mode does not apply Audyssey to the front speakers at all.  

    It is not a mode that we recommend or support.  The Flat setting is too bright in most rooms so this is why we developed Audyssey Reference with a slight high frequency roll off.

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    Chris Kyriakakis

    Hi Robert,

    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.  It is possible that this is giving the proper balance and that the bass lines are now clearer.  There is a psychoacoustic relationship between the high and low end and the balance between the two.

    Your room is quite large and so I wouldn't put it in the "highly treated" category.  Keep in mind that too much absorption is not a good thing.  There is a "just right" amount that is determined by the acoustical properties of the room.  

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    robert Carman

    Thank Chris, that does make sense....the bass seems a bit claerer (more pronounced) because it is not overwelmed by the higher frequencies. I am adding some diffusion also...in the pic I only have absorbition as reccommended by Auralex. I thought I was loosing detail at first with the Audyssey curve but after listening (Tested it with my game system) it seems more corect. I will admit I like high pitched sounds LOL!! So you do NOT reccommend the Flat curve at all (Except for music)? The flat curve does sound better than it did.....the treatments helped.

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    Chris Kyriakakis

    I wouldn't recommend the Flat curve unless you have a smaller room with a lot of absorption--none of which seem to apply in your case.  Best to test with film content on Bluray.  Game content is mixed under unknown conditions and is probably not the best choice to decide on a reference curve.

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    robert Carman

    You are spot on again Chris....I thought I was loosing detail and I added som diffusion on my back wall and above MLP and it is unreal and I mean the best sound I have ever heard from my systyem and that is with the Audyysey curve. Hands down the best!

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    Spyder

    All systems use the same curve?

    From 2EQ to MultEQ XT32

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    Chris Kyriakakis

    Yes, the target curve is the same for all.  But, of course, the ability to achieve it depends on the resolution of the filters.

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    Rob Brooks

    Chris, 

    Where would I find a graphic representation of the "standard" Audyssey target EQ curve.

    i.e the target SPL of each frequency band (measured at reference level)

    Specifically for MultEQ XT equipped devices.

    or is this not available 

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    Chris Kyriakakis

    Hi Rob,

    It's not generally something that we publish.  The curve is flat out to about 8 kHz, then dips to about –2 dB at 10 kHz and then a little more at 20 kHz.  It's based on our multi-year experience with measurements in studios and a database of several thousand rooms that we have collected.

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    Robert M. Bridi

    Hi Chris,

    Are all the MultEQ XT curves in different products the same?  For example, on the NAD website under the T 775HD2 A/V Surround Sound Receiver Features it states "Audyssey MultEQ XT Room Correction with custom NAD developed target response curves".  Is the curve in my Denon AVR-989 which has MultEQ XT the same as that in the NAD T 775HD2?

    Thanks in advance.

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    Chris Kyriakakis

    Hi Robert,

    NAD has their own target curve that is found on NAD gear.  It's very similar to the standard Audyssey curve found in all AVRs.

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    Ross Gauthier

    Hi Chris. I have a question regarding target curves and MultEQ calibration. I understand that the target curve for Audyssey Movie Ref has a slight roll-off. My question is the high frequency roll-off the same for every receiver? I've read that its about 3-4 dbs. Or does Audyssey select the appropriate roll-off for the room. I know THX Mode is just a standard roll-off, so I was wondering if Audyssey roll-off is similar in that regard.
    Thanks.

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