Sub EQ & X-over Frequencies

My system comprises Denon AVP HCDI(A), five Genelec 1038's, 4 Genelec 8040's and a Velodyne SMS-1 driving two SVS PB12 NSD subs.

My Music/HT room is purpose built and acoustically treated.

After running MultEQ XT (5 positions), all levels and distances seemed to be correct but I have the following questions:

1. Why are there were no crossover frequencies displayed for any speakers?

2. After Audyssey has completed its runs and I set all speakers to small, 80Hz X-over, and let the SMS do an LF sweep (15Hz to 250Hz) there is a 15dB dip at 63Hz that I can virtually remove by phase inverting the drive to the subs. There is also an 10dB peak at 32Hz, subs phase inverted or not. Why doesn't Audessey correct for these issues and/or show a phase error?

3. Although I have tried to run the MultEQ process with no SMS-1, with the SMS flat or run the MultEQ process after I have let the SMS-1 do its equalization there seems to be little to no equalization being applied to the subs by Audyssey. I check the Audyssey EQ by setting the Denon speaker crossover frequency to 250Hz for all speakers (powering down all speakers except subs) and then running the SMS-1 sweep tone. This ensures that virtually the entire sweep is directed only to the subs and I am not monitoring anything from any other speakers. 

In each of the above three approaches switching the Audyssey EQ in and out shows little to no change in the sub sweep, why?

4. I also read in the Audyssey technical literature on this web site that MultEQ XT only supports 8 channels, is this true, and if so how would it EQ my 10 channels (SUB/LF/C/RF/LSA/LSB/RSA/RSB/LR & RR)?

Listening to the system as Audyssey leaves it, and setting all speakers to small with an 80Hz X-over, produces far too much very low bass with virtually no upper bass register, even after I apply the phase inversion to the subs. The upper bass sounded none existent with no phase inversion. 

After running Audyssey and setting all speakers to small with an 80Hz crossover, phase inverting the subs and using the SMS-1 to manually "re EQ" my subs, my LF frequency response is +,- 2dB from 15Hz to 250Hz. The system now sounds outstanding on all film material and excellent for music with pin-point imaging and depth perspective, but "seems" to lack bass for some music and seems to be a little "bright". I do realize that I could have different settings for bass levels for Music and Film, but it varies significantly from album to album, something I never really noticed before. Maybe I got used to "muddy" bass!!

I would be very grateful for any help or advice with any of the above questions or observations as I am concerned that I may be doing something wrong with Audyssey or in the way I am running my tests. However, my ears (and my wife's) seem to confirm what the SMS-1 is displaying and unfortunately Denon does not display the Audyssey EQ applied to the subs only the other nine speakers.

Regards

Paul 

 

Paul Berg -
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2 Comments

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  • 0
    Avatar
    Audyssey Labs

    Hi Paul,

    1. Not sure where you are looking for the xover frequencies.  Denon sets these (not Audyssey) based on the measurement info MultEQ passes to the bass management system.  They can be found in the Setup Menu under Speaker Settings-->Crossovers

    2. Sine sweeps with the mic in one position are totally inaccurate!  There is very little useful  info to be gained from these... To measure low frequencies correctly one must take multiple measurements and then combine them according to the distribution of the problems found.

    3. Does the SMS sweep tone run through the AVP? Which input are you using to feed it to the Denon?

    4.  Not true.  MultEQ XT will support as many channels as the AVR maker provides.  There are already products with MultEQ XT that have 9, 10 and 11 channel support.

    Re: bass.  It sounds like you have very specific preferences and that's really outside the premise of what Audyssey delivers.  It is designed to give you a smooth bass response that matches in level the other speakers.  These are the reference conditions used in the mix.  Personal preference for more or less bass or for music and movie settings (I never understood the need for this one...) are just that: preferences.  Nothing wrong with them, but they have to be applied outside of the Audyssey calibration.

  • 0
    Avatar
    Paul Berg

    Chris,

    1. The recommended cross over frequencies I am referring to are those shown in the Denon Audyssey information table that show the Audyssey results, NOT the actual cross-over frequencies that I would set in the speaker setup section.

    2. Even though I agree that a single mic sweep result may be challenged, I get the same results no matter where I place the mic within the seating area I.E. no change in the subs EQ when I engage or disengage the Audyssey EQ.

    3. I am using an analog stereo input which shows both AL24 and Audyssey as being active in the display.

    4. Thank you for reassuring me.

    While Audyssey did set all the distances and levels correctly and did an excellent job on the EQ of all the satellite speakers I still fail to understand why the EQ on the sub is clearly so incorrect. The resulting bass is anything but "smooth"; VERY bottom end heavy and very light on upper bass. This appears to be supported by both the SMS sweeps, no matter where I put the mic in the listening area, and my ears.

    I will run Audyssey yet again this weekend to see if I can better my current results.

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