BFD: Equalize to what level?

Discussion in 'Archived Threads 2001-2004' started by Ari, Feb 27, 2002.

  1. Ari

    Ari Stunt Coordinator

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    I've been playing around with my BFD (hooked up to Energy eXL-S10) and am wondering to what level should I equalize it?

    Here are my initial readings bypassing the BFD (RS meter compensated, sub only):

    Freq. SPL

    15hz 76.5dB

    17.5 82

    20 88.5

    22 92

    25 97

    28 100

    32 105

    36 103.5

    40 100.5

    45 99

    50 96.5

    56 101.5

    63 112.5

    71 108.5

    80 101.5

    89 106.5

    100 98

    112 95.5

    126 88.5

    142 78.5

    160 75.5

    As you can see, my frequency response is all over the place and I don't know what SPL I should be aiming for. Should I go for something around 95dB, which is the low for 22-112Hz or should I go for 90dB which is the low for 20-126 dB? Or maybe I should aim for something else?
     
  2. Sonnie Parker

    Sonnie Parker Second Unit

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    Here's a graph of your readings:
    [​IMG]
    Typically I believe most people use 85db as setting level.
    What is the rated frequency response of that Energy sub?
    You may be starting out too high. If the response is only effective down to say 30hz or so then I would start my readings where 28hz would read 85db and measure from there. Then try to get your line around the 85db level.
    After you get it smoothed out you can turn your volume up as you wish. You don't necessarily have to measure it at the maximum level you will listen.
    It appears you won't have a lot of problems fixing up a flat line and/or a house curve.
     
  3. Ari

    Ari Stunt Coordinator

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    Sonnie,

    Let me see if I get you.......according to Energy's website, the sub specs to +/- 3dB at 25Hz....therefore I should initially set volume so that it hits 85db at 25Hz and equalize from there?? Do I just live with the drop below 25hz?? Will equalizing to 25hz give me the greatest headroom?

    I've used two channels of the BFD to equalize to both 20 and 22hz....still haven't had a chance to compare the two though.
     
  4. gomez_a

    gomez_a Stunt Coordinator

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    don't wanna stress you, but there's what's known as EQ'ing to a "House Curve" - but let's not go there for now [​IMG]
     
  5. Ari

    Ari Stunt Coordinator

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    I actually am aware of the "house curve" and put a 12dB rise from 100hz to 40hz in one of the settings I made. I haven't decided yet if I like it since I haven't quite had enough time to evaluate it vs. a flat curve.
     
  6. gomez_a

    gomez_a Stunt Coordinator

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    I want to try a house curve as well, the trick will be in determing the rise to use for my room (12Wx19Lx81/2H) - which opens up to a fair size kicthen/dining room area - Fun, Fun, Fun [​IMG]
     
  7. Sonnie Parker

    Sonnie Parker Second Unit

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  8. Ari

    Ari Stunt Coordinator

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    Thanks Sonnie....

    I actually have no plans to boost below 25hz (only cut)......I was just wondering if it would be better to equalize to the level of, say, 20hz or 22hz instead of 25hz. If I equalize to 20 or 22, I can go lower but if I go 25, I could go louder (or at least that's how I see it). The Energy uses a weak 100W MOSFET amp.....I think it can max at 400.

    And then the issue of the house curve.....by how much should I curve?? The room is 17'x22'x9' and is sealed.
     
  9. Sonnie Parker

    Sonnie Parker Second Unit

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    Ari,
    I'll have to find the thread on this but there's one that can explain this better than I think I can. But in summary, if you try to start with 20hz or 22hz and cut all other frequencies to this level then you will end up having to turn your amp up and thus you in essence boost a much broader range using much more of your amps headroom. Does that make sense?
    With that amp I would start with 25hz and set it to rs corrected 85db spl. This is what it could look like or close to it (take new measurements to make sure):
    [​IMG]
    Now, you never did say if you measured the sub with the mains or not. If you measured with the mains you need to start over without them.
    You never stated your x-over point. If you measured without your mains I would guess it's at 100hz.
    As far as how to adjust, I would try several different setups and take a listen and see which you like.
    If it were me I would try a couple of different ones as such:
    I would flat line one, get everything down to 85db. It doesn't have to be dead on 85 db but try to get the line within + or - 3db or so. You should be able to do this with about 3-4 filters. Check out the BFD Page to get acquainted with setting up filters. I could make suggestions but it's better for you to experiment and learn it so you will know how. It may take you a good bit of experimenting but it will be fun to learn it.
    Then you can try a couple of different house curves. You may even try leaving the 32hz peak alone and try bringing the 63hz and 89hz peaks down to 85db and see what that sounds like.
    Then you could try bringing from 28hz to 40hz down to about 88db and then slowly roll off from 88db at 40hz on out to around 80db at 100hz. That would give you a fairly flat line from 28hz to 40hz and an 8db slope from 40hz to 100hz.
    Again, it would be good to try several.
    Search out these other post to. These other fellows know much more than me and can probably give you some better info than I. Whatever you do, don't just listen to me.
    I'm surprised no one else has jumped in here. I'll see if I can get us more help.
    Just remember, these are suggestions, you'll have to be satisfied with whatever you do.
     
  10. Ari

    Ari Stunt Coordinator

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    Sonnie,

    Once again, thanks for the help. It's actually your instructions and spreadsheet that I've been using to fiddle around with the BFD. All other instructions are a far cry from what you've put together.

    Sorry about being vague with the details that you've requested.... I did measure with only the sub and it's crossed over at the receiver--90hz.

    I guess I was being hopeful about getting my sub to 20hz. But then again, getting flat response to 25hz isn't so bad.....

    I'll try to do what you suggested this weekend and will let you know what happens.
     
  11. brucek

    brucek Second Unit

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    Sonnie says,

     
  12. Sonnie Parker

    Sonnie Parker Second Unit

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    Thanks Ken,

    I feel better having some verification on this. I just didn't want to lead him astray. I figured I was at least fairly close but wanted to make sure.
     
  13. Wayne A. Pflughaupt

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    Wayne
    Thanks for running this one, Sonnie. I’ve been kinda swamped the past few days with people asking for help EQing their subs and didn’t get to this one.

    Regards,

    Wayne A. Pflughaupt
     

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