Is a full range equalizer "wasted" on a subwoofer?

Discussion in 'Archived Threads 2001-2004' started by EdNichols, Feb 24, 2003.

  1. EdNichols

    EdNichols Second Unit

    Joined:
    Feb 15, 2003
    Messages:
    372
    Likes Received:
    0
    Trophy Points:
    0
    I have read where using an equalizer on a passive subwoofer can help with some of the "boomy" sound that comes from subwoofer location. This makes sense but what I don't understand is how an equalizer with a 20hz-20kz range would do any good for an LFE channel that is 20-100 hz or so. It seems like only the lowest settings of the equalizer would have any effect on the the sound and the remaining higher frequency settings would be wasted? Can someone shed some light on this?
     
  2. PaulT

    PaulT Supporting Actor

    Joined:
    Oct 28, 2002
    Messages:
    932
    Likes Received:
    0
    Trophy Points:
    0
    Ed, a Behringer Feedback Destroyer (BFD DSP1124P - do a search in these forums) is normally used by some here to EQ Subs. They are made for reducing feedback through microphones or monitors in the Music Industry and are available at Music Shops for 150USD MSRP.

    They are fairly 'noisy' for HT above 1kHz but for low frequencies they are fine, so are used by Home Theatre enthusiasts for EQ'ing 120Hz or so and lower. The BFD has 2 channels with 12 adjustable frequencies per channel (unless you have 2 subs, only one channel is used). Each af the 12 filters includes Frequency, Bandwidth and Gain.

    It's not your typical Parametric EQ with slider bars set at 1/6th or 1/12th Octaves that you may be familiar with.

    Check out http://www.behringer.com
     
  3. Rick_Brown

    Rick_Brown Second Unit

    Joined:
    Oct 25, 2001
    Messages:
    449
    Likes Received:
    0
    Trophy Points:
    0
    Deleted. Paul's answer above is better!
     
  4. EdNichols

    EdNichols Second Unit

    Joined:
    Feb 15, 2003
    Messages:
    372
    Likes Received:
    0
    Trophy Points:
    0
    Paul,
    Thanks for the info. What had me a little confused is that SVS for example offers a full range 31 octave EQ for use with their subs.
     
  5. ColinM

    ColinM Cinematographer

    Joined:
    Dec 9, 2001
    Messages:
    2,050
    Likes Received:
    0
    Trophy Points:
    0
    I use a 31 band..

    8 bands of eq (20, 25, 31.5, 40, 50, 63, 80, 100) are better than none. I am quite happy with the results, as I had an uneven response that is much better now.

    I just don't look at the detailed resolution - 1/3 only. That way I fake myself into thinking it's nice and flat.

    So far so good.
     
  6. PaulT

    PaulT Supporting Actor

    Joined:
    Oct 28, 2002
    Messages:
    932
    Likes Received:
    0
    Trophy Points:
    0
    I haven't seen the specsheet other than the small photo on their site, but the Art unit is a 31 band 1/3 Octave with ISO spacing. On the lowest 'band' setting that should give you centre frequencies of:

    20.0, 25.0, 31.5, 40.0, 50.0, 63.0, 80.0, 100.0, 125.0 etc etc to 2kHz, which would make it quite nice for a Sub.

    You would use it on the lowest band setting and would only require the lower 8 or 9 centre frequencies out of the 31 available.

    I would prefer something along the Rane line or BFD due to it being able to change the centre frequency.

    Course it takes a while to type the numbers out and I see Colin has answered the question [​IMG]
     
  7. Wayne A. Pflughaupt

    Moderator

    Joined:
    Aug 5, 1999
    Messages:
    6,207
    Likes Received:
    56
    Trophy Points:
    9,110
    Location:
    Katy, TX
    Real Name:
    Wayne
    Ed,

    The deal is, you’re looking at equalizers (1/3-octave presumably?) that were designed for full-range use in professional applications, not home theater sub applications. Since no manufacturer has come out with a graphic equalizer dedicated for subwoofer application (i.e., all bands below 125Hz or so) home theater enthusiasts have been forced to use professional equalizers to fit their needs.

    As to whether or not all those extra filters are a “waste,” I have to ask: Do you use every feature on your TV or receiver? Every input?

    All that really matters is if the equipment in question does what you need it to do at a price you can afford.

    Certain parametric equalizers are designed so that all filters can be assigned to bass frequencies. However, even with those, there’s a good chance you will not need or use all available filters. For instance, the Behringer Feedback Destroyer that Paul mentioned has a total of 24 filters than can be assigned anywhere in the frequency spectrum; this means that all of them can dedicated to the bass frequencies. The chances are slim to none that you would need or use even half of them.

    Bottom line, the goal of equalizing a sub is not finding an equalizer with the precise number of filters you need, even if that was possible. The goal is to improve room response and therefore your sub’s performance. One member of this Forum who is familiar with the benefits of equalizing subs has stated, “A $300 sub that has been equalized will sound better than a $1000 sub that has not.” Maybe that will help make those “wasted” filters go down a little easier. [​IMG]

    Regards,
    Wayne A. Pflughaupt
     
  8. EdNichols

    EdNichols Second Unit

    Joined:
    Feb 15, 2003
    Messages:
    372
    Likes Received:
    0
    Trophy Points:
    0
    Thanks Wayne. That does put it in to perspective.
     

Share This Page