My SPL Curve, how bad is this?

Discussion in 'Speakers' started by Jeff Braun, Apr 12, 2003.

  1. Jeff Braun

    Jeff Braun Auditioning

    May 13, 2001
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    After making the proper adjustments for the Radio Shack SPL meter, here are the readings

    Hz db
    16 79.5
    18 79
    20 79.5
    22 76.5
    25 78
    28 84
    31.5 81
    36 84
    40 91.5
    45 93
    50 93.5
    56 93.5
    63 85.5
    71 77.5
    80 78.5
    89 75.5
    100 67
    111 79
    125 78.5
    142.5 88
    160 86.5

    Note that the crossover between sub/mains is at 80 Hz. To me, this looks like a disaster. I got the SPL meter in the first place because I could clearly tell that my bass response was uneven when listening to music. It's pretty clear why I was able to discern that, looking at these readings. Anyway, I live in a dorm room right now, and I have no other place to put the sub other than where it is. I guess I could try to fix things with a parametric equalizer, but this looks to be a problem beyond just equalization. I figure I'll try to do better with placement when I move to my new place. Any comments?
  2. Jeff Braun

    Jeff Braun Auditioning

    May 13, 2001
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    Note that I have an SVS PC 20-39, so I should be able to get relatively flat response down to 20Hz or so.
  3. Brian L

    Brian L Cinematographer

    Jul 8, 1998
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    The peak you have from 40 to 60 Hz or so (which I bet makes things sound a bit boomy) is most likely due to placement of both the sub and the primary listening location.

    A proper EQ would help this a lot (assuming you can not, as you said, move the sub or your listening spot). In fact, that is what a proper EQ is made for.

    Although I do not use one, I have read great things about the Behringer Feed Back Destroyer, which is a digital, multiband, parametric EQ. Search for BFD here and in the DYI forum. There is lots of info to be had, and its cheap (~$100 or so).

    And no, your measurements are in no way unusual. Every room with affect the bass to one degree or another. When I hear of users that have supposedly "flat" bass (as measured in room with a proper meter), and yet have no EQ, I really question how that is possible.

    Personally, I use an AudioControl Bijou Home Theater EQ, which has 1/6 Octave control below 80 Hz, in addition to 80-800 Hz, 1/3 Octave on the front trio.

    I am probably +/- 3 dB from 80 Hz on down, at least on the 1/6 octave frequencies. That's not really too bad, but I have seen plots from BFD users that get it a lot tighter than that.

  4. Wayne A. Pflughaupt

    Aug 5, 1999
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    Katy, TX
    Real Name:

    Since you can’t move the sub, your best bet is to get a parametric equalizer. Actually, an equalizer is preferable, because no amount of trial-and-error relocating will get the response that a parametric equalizer will.

    No need to assume your curve is “beyond equalizing.” Equalizing isn’t necessarily about achieving “perfect” response, but to improve response. You don’t have to get picture-perfect response to have great-sounding bass.

    Wayne A. Pflughaupt

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