Subwoofer; Lack of bass

Discussion in 'Speakers' started by Nick.H, Apr 22, 2004.

  1. Nick.H

    Nick.H Stunt Coordinator

    Sep 18, 2003
    Likes Received:

    Since redesigning my HT room to fit my projector Ive noticed that my subwoofer which was once in a corner seems to be lacking in the bass department.

    I was wondering if I had any other positions I could try?

    From the way its setup I don't think I do. I need like a bass testing DVD of some sort or some good movies... can anyone recommend some to use for testing?

    I normally use, U571 & Behind Enemy Lines
  2. Alex_P

    Alex_P Stunt Coordinator

    Nov 3, 2003
    Likes Received:
    Check out "The Haunting" DTS version and "Titan AE" also in DTS... You'll be amazed...
  3. BenCosta

    BenCosta Agent

    Jan 8, 2004
    Likes Received:
    Try putting the sub in your listening position and then walk around the room until you find a point where the bass sounds the best. When you do, put the sub in that spot.

  4. John Garcia

    John Garcia Executive Producer

    Jun 24, 1999
    Likes Received:
    Real Name:
    You also need to calibrate the level with an SPL meter. Corner is *usually* the best place, but it really depends on the room. I agree, if you can do it, try putting the sub in the lisening position.
  5. Andrew*S

    Andrew*S Auditioning

    Mar 21, 2004
    Likes Received:
    The corner is the location that excites the most room modes. If you moved it out of the corner, you'll have sub frequency ranges which will have dropped dB's.

    If you calibrate your subwoofer with a RS meter, you will be calibrating to your sub's peak and you will find large portions of the subwoofer range lacking leading to your observation that your sub is "lacking in the bass department".

    Here's an example. I have dual SVS 20-39's. When I first calibrated the subs, I used the pink noise from my receiver to make sure all the channels were at the same SPL. When I used the subwoofer tones that are in 2Hz increments (20Hz, 22Hz, etc) and plotted a graph, I noticed that I had a peak of 15 dB at around 51 Hz. This means when I calibrated using the pink noise that I calibrated to the peak and there were frequency ranges on my sub that were 15dB quieter than the peak. Usually, a 6dB difference is doubling in sound so this meant that in some ranges, my sub was 1/3 quieter than the peak. This made my sub sound flat and "lacking in the bass department".

    There are several solutions....

    1) Bass traps. I don't know anything about these other than they help try to flatten your sub frequency response curve.

    2) Sub placement. You can find out your room modes and try to move the sub into a null to tame the peak. You can calculate room modes from this document - there is a link to a "room mode calculator" in an excel spreadsheet (w*

    3) Equalization - I got a Behringer DEQ2496 (a BFD - Behringer Feedback Destroyer) works well also) and I have parametrically equalized out my peaks to make my sub freqency curve basically flat with a slight house curve of 6dB running from about 50Hz down to 20Hz. So now, to my ears, all frequencies on the sub sound about the same level and they aren't boomy at any places or lacking at any places. You want a parametric equalizer here and not the traditional "slider" type of equalizer.

    You should be able to pick up a BFD for around $119 from zzounds, music123, or musiciansfriend. Search the forums for more info on the Behringer Feedback Destroyer.

Share This Page