DVE does not work so now what?

Discussion in 'Speakers' started by Victor Ferguson, Jun 17, 2005.

  1. Victor Ferguson

    Victor Ferguson Stunt Coordinator

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    I am trying to get my sub calibrated but do not have AVIA. I have a copy of DVE but apparently the sub test tones are not very accurate to say the least. I was hoping someone could help me out on this one. O.K. heres what tools I have to work with on this problem. I have a SPL meter, DVE, Real Traps Test Tones CD(1hz increments). What I tried last was this.
    I set my mains to large, disabled sub and tested response with a inintial spl of 75db at 60hz. They stayed pretty flat from 100hz down to about 35hz with a 12 db spike around 80hz. I then unhooked mains, enabled sub and set it set it at 75db with the 60hz tone. The sub wasnt as flat as the mains but had good response down to about 28hz with a big spike at 80hz as well. I then hooked everything up, crossed sub over at 80hz and it was pretty flat from 28 - 120 hz with the 80hz spike being the exception.
    So the questions are:
    1. Is there a better way to do it?
    2. My mains go pretty low and the sub isnt really helping them much but my center and surrounds cant go that low. I have the ability to cross each over seperatly. Is it better to set the crossover on the mains at 40hz and the surrounds/center at 80hz or just cross them all over at 80hz.
    3. With the exception of the spike at 80hz the mains are really flat, should I leave them like they are or try to move them farther away from wall to reduce bass coming from them to get rid of the spike at 80hz.
    4. Seeing as how I have a big spike at 80hz should I try to avoid this as a crossover point?

    Sorry for the long post but any help would be appreciated.
     
  2. BillyHC

    BillyHC Agent

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    Go to svsubwoofers.com and look for their FAQ on calibrating Subs.
    They explain how to properly use AVIA and DVE.
     
  3. Kevin C Brown

    Kevin C Brown Producer

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    Victor- Your thinking is good.

    DVE is not good for sub cal.

    You can use discrete tones, and just make sure you have flat reponse above, at and below the crossover freq (if you know what it is). There will always be peaks and valleys from the room, but you should be able to still use discrete tones.

    But... Have you found the Radio Shack adjustments for its low freq error?

    And, you could double check by using the tones your receiver/pre pro has.

    I would still suggest getting Avia. Other good stuff on it besides calibrating LFE... [​IMG]
     
  4. Jeremy Anderson

    Jeremy Anderson Screenwriter

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    If you have relatively flat frequency response from your sub, calibrating to 82dB with DVE (vs. 75dB for the speakers) will get you there. But that's heavily dependant on your in-room response because of the shape and wide bandwidth of DVE's subwoofer tones. Honestly, I would just stick with your receiver or pre-pro's tone instead.
     
  5. Daman

    Daman Second Unit

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    I have DVE as well, and a SvS. I got very good advice from this forum and from SvS regarding this matter.DVE can be used to calibrate the sub as well, just calibrate your subwoofer 10dB hotter than the rest of the speakers because the LFE track is recorded that much off.Hope this helps.
    Daman
     
  6. Victor Ferguson

    Victor Ferguson Stunt Coordinator

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    Thanks everyone for your input. As far as the crossover point goes, I currently have it set at 60hz. I believe the spike I have at 80hz is due to the room and I guess I'll have to get a BFD to fix sub response but that wont fix the mains being hot at 80hz, so should I avoid using that as a crossover point? I will go home tonight and try using DVE but keep in mind the 10db problem and see how close the other method was to its results. Thanks again everyone for the input.
    EDIT - So one more question. On DVE there are band limited test tones and full bandwith test tones. Which ones should I use to calibrate?
     
  7. GregBe

    GregBe Second Unit

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    This is counter to what is usually recommended, but you may want to try this. In another forum, the head designer of the Newton Series from Cambridge soundworks posts quite often. He suggessted that many rooms have a peak in the 80hz region, and that bringing down the crossover on the sub will cause some cancellation which could work to your advantage in your situation as it may bring down that peak. If you do this, you will probably have to recalibrate to bring the overall sub level up. If you like it, great, if not, it is very easy to put it back the way you had it.

    Greg
     
  8. Victor Ferguson

    Victor Ferguson Stunt Coordinator

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    Thanks Greg, that was a wonderful suggestion and I had not thought of that. I had read not to ever do that, but in my situation it may just be helpful. Thanks again for the great idea it is defiantly worth a try. I'll post back after I try that as well and let everyone know how it went.
     

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