Problems at 56 hz with BFD

Discussion in 'Archived Threads 2001-2004' started by TrevorST, Jan 12, 2003.

  1. TrevorST

    TrevorST Stunt Coordinator

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    Well after getting passed my first hurdle trying to equalise my SVS sub with a BFD I have now hit another. I had some good peaks at 56hz and 63hz so I set a filter for each. The 63hz peak came down easy but the 56hz peak refuses to move I double & triple checked that it is set to hz). No matter how much I lower the 56 hz filter it still stays the same, even though the 50hz and 63hz will start to lower if I reduce to -15 and beyond or open up the bandwidth.

    Help.....
     
  2. Shawn Solar

    Shawn Solar Supporting Actor

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    Make sure that the band is set to PA. and not to OFF. I've made that mistake myself.
     
  3. TrevorST

    TrevorST Stunt Coordinator

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    I did double check that PA was active. Plan to try using a wider band at 63hz and remove the 56hz filter and see what that will do. Tried listening to a concert last night and ended up bypassing the BFD as I thought the bass sounded better (less boomy) with out it.
     
  4. Massimo N

    Massimo N Stunt Coordinator

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    Make sure that you are activating both channels, or that you are setting the EQ on the correct channel. On the BFD, there are 2 independent EQs, the LEFT Channel and the RIGHT Channel. I use 2 subs, so I normally have to test on one channel before I proceed. Since your able to make a change, I don't suspect this is your issue.

    Also make sure that your mains are off. I normally don't have a probem at 56hz (I have my mains Paradigm Studios 40s set at small). Depending on your speakers and your Bass Management Setting (Small/Large/Sub Out/Both etc) your mains can be sending more info than your sub is.

    One other thing I can suggest is make sure you are not trying to change khz. You have to look at the display closely, because the "K" is very small. To ensure that I don't set the wrong filter (I did it once and it drove me nuts), is to start at 20hz and work slowly up to the desired frequency.
     
  5. TrevorST

    TrevorST Stunt Coordinator

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    Thanks massimo I already went through the pain of the problems you describe so I double & triple check them. This is a real headache... I seem to be able to modify everything but the 56hz peak. This makes the equalised sound worse than the raw.
     
  6. Kevin C Brown

    Kevin C Brown Producer

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    You could try to use 2 filters there, but each at 1/2 the attenuation of the the total you want. Something to try... [​IMG]
    If there is something funky going on with the BFD, you could also try something slightly different, 57 Hz or 54 Hz or something.
     
  7. TrevorST

    TrevorST Stunt Coordinator

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    Well I got it.... It took a lot of playing (several days) but I have a nice gentle curve down to 80hz (I do have a slight 2db peak at 56hz but other than that it looks and sounds great. What surprised me was even though my crossover is set at 80hz I was able to effect the sound up to 125hz quite a bit. I used to have a real gap at 100-125hz but was able to eliminate it with the BFD.
     
  8. Wayne A. Pflughaupt

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    Did you dial in a house curve?

    Regards,
    Wayne A. Pflughaupt
     
  9. TrevorST

    TrevorST Stunt Coordinator

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    I did kind of. I tried to get the RSL meter reading to as close to the same on each frequency as possible. This gives a natural curve because of the errors in the RSL. If this is not enough then I can go in and tweak where needed. But I do like the sound with the current curve.
     
  10. Wayne A. Pflughaupt

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    Trevor,
    IMO this is not a good way to get a house curve. This is because the RS meter doesn’t start with serious deviations until 40Hz – not the optimal place to begin a house curve. You might want to check the information at these links. One of them describes in detail why I don’t like the “set it for flat and let the meter get your curve” method:
    http://www.hometheaterforum.com/htfo...918#post499918
    http://www.hometheaterforum.com/htfo...014#post530014
    Regards,
    Wayne A. Pflughaupt
     
  11. TrevorST

    TrevorST Stunt Coordinator

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    Thanks Wayne i understand and will go back and change to add a little more after 40hz. I have a nice drop to around 50hz then it levels off a little.
     

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