Subwoofer output and calibration

Discussion in 'Archived Threads 2001-2004' started by David Ely, Oct 9, 2001.

  1. David Ely

    David Ely Supporting Actor

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    This is something that I've been wondering about for a while. I'm still not quite sure how I'm going to word this so it makes any sense, but here I go.
    I have a Paradigm PW-2200 sub. It's a great unit, and I love it to death. I currently have it calibrated about +10dB hot (this value is corrected for the Radio Shack SPL meter), and I usually listen to movies at -10dB from reference.
    Any louder and I tend to get distortion in my front channels. I believe this is caused by the amp straining to play at higher volumes). Everything's been calibrated with VE.
    Here's where I'm going to have trouble explaining things, so I'll start with an example. Let's take the Neo / Morpheus duel in The Matrix. When Morpheus does his nice slam in to the floor, there is a nice bass punch. When I pull out my SPL meter, I read 100dB (uncorrected). Reading on the net, I find that most people with really great subs (Let's say a pair of SVS CS) will get 110dB (probably a corrected value), and their sub is only calibrated +3 or 4 dB hot (corrected value).
    This to me says that my sub just doesn't have the output of the higher end sub, and that's fine. I don't expect my sub to give that type of output (my room couldn't handle it). But why does my sub have to be set higher, just to give
    lower output?
    The highest output that I tend to get in my HT is around 100dB on the SPL meter. I'm very happy with this, but I'm just trying to understand what's going on.
    Let me ask this question. Since I'm listening at -10dB from reference, and have my sub calibrated 10dB hot, does this mean my sub is giving similar output as if I was playing a reference level with the sub calibrated neutral (not hot or cold) to the other speakers? If so, then I'm probably pushing my sub to its limits.
    Would this mean that people with low to mid-range subs should calibrate higher than those with high-end subs? Because the output of the lower-end subs would be generally lower.
    Hmmm ... am I making any sense? I'm going to post this as is right now, and I'll probably add more later. Maybe someone here will actually understand something in this post and could add some insight.
    [Edited last by David Ely on October 09, 2001 at 12:54 PM]
     
  2. Lou Sytsma

    Lou Sytsma Producer

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    Dave - what type of a receiver are you using?
    It's difficult to give an answer without knowing your setup.
    Basically though your DD and DTS LFE trim should be set at their upper range 0, 10+ whatever it is. It varies from receiver to receiver.
    Then your LFE level should have a setting from -20 to 0 - again this depends on the receiver. That's the range on my Yamaha.
    This should be set around the lower 3/4 mark - in my case -15. On the sub the power/output level should be around the 5/8ths mark. If you are using the cross over of your receiver set the crossover of your sub as high as it will go. This will prevent crossover cascades between your sub and the receiver.
    From there calibrate your sub. If it is way off adjust the power output level of the sub. Use the LFE level on your receiver to fine tune the bass output.
    Hope that helps and makes sense.
    [Edited last by Lou Sytsma on October 09, 2001 at 02:37 PM]
     
  3. David Ely

    David Ely Supporting Actor

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    Hmmm ... I had a feeling I might be miss understood. I'm not at all concerned that my setup is incorrectly calibrated. I'm actually trying to figure out a few things about subwoofer performance after calibration. How about this, let me repose two questions from above.
    1) Does it makes any sense to calibrate a sub, that has a lower general output, higher than a sub that has greater output?
    2) If you listen to your system at -10dB from REF and have you sub running 10dB hot, are you getting the same bass levels as if you were watching at REF with the sub calibrated to the same level as the rest of the speakers (75dB with VE)?
     

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