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40hz or 100hz? bass pre

Discussion in 'Pickups & Electronics [BG]' started by thehangingmist, Feb 1, 2013.

  1. i've heard 100hz = mud!
    is that true? am looking at buying a preamp and some have the bass frequency centered at 100hz and some have it at 40hz. should i really avoid the pre with bass eq set at 100hz because boosting that frequency can make the bass sound very muddy?

    am asking because the pre's with bass eq at 100hz have the 3 pot pre-wired lay out and the 40hz pre's have a 4 pot lay out for some reason and i need to fit it on a jazz bass control plate without having to route anything!
  2. Meddle


    Jul 27, 2009
    I always thought 200Hz was where the mud lay, though any bass frequency seems to be muddy when done wrong. If you cut too much 100Hz you end up sounding a bit lifeless. However the 'bassy' Jamerson tone, on record, has a lot of stuff cut below 200Hz. It depends what drives your particular band. 40Hz seems really low. I would be interested in the width of frequencies that these EQ filters cut or boost as well as their centre frequency before making too much of a guess.

    I've been reviewing a couple of demo records recently, and one doom band had the bass so agressively low-pass-filtered that you couldn't hear any of the character of the bass. It wasn't muddy, and all the 100Hz stuff was there and present, but it lacked character.
  3. topo morto

    topo morto

    Mar 22, 2010
    No, no particular EQ frequency "= mud".

    What is a useful EQ point depends on the sound you want to aim for, the pre-EQ sound of the bass you're EQing, your playing style, the band mix, your amp, the room... not to mention the type of EQ (shelving or peaking) and the cutoff, and how much you are boosting, and of course what notes you are playing.

    How about doing some experiments with an external EQ or software to try out various EQ curves before going to the hassle of installing a preamp?

    IMO the best EQ is no EQ - having a bass that sounds how you want in the first place (though of course that often isn't possible).
  4. sratas


    Dec 15, 2007
    Parma, Italy
    100-150 Hz is not "mud", but "body and boom".
    of course I'm talking about the sound of this frequency range when boosted eccessively. this is also a crucial point to tweak in a preamp stage if you want to fight against problematic environments and rooms. many times if you do a little cut there you regain definition without loosing body, only boom.
    If I were me, I'd prefer a shelving low EQ centered to 100 Hz instead of 40 Hz. The vast majority of bass cabs and PA fail to reproduce the 40 Hz thing and many reference tones of history, for example the Ampeg tone, are built far higher than 40 Hz.
    It doesn't really matter those 40 and lower, even if the first harmonic (B and E) resides here. At those frequencies the human hearing has reduced sensibility and you almost feel it instead of hearing it (you mainly feel it because of bone transmission of sub sounds, via your skull).

    200 Hz is a key frequency for bass and many folks find that playing in this range allows to scuplt the tone, grunt and punch quite easily. This is were you can find "body" and projection without straining your equipment.

    Obviously, any frequency is important, but some are more bass specific importance-wise.

    Other examples:
    - 400-500 (useful for cut mainly, to avoid nasal tones, to reach definition)
    - 800 (presence, cut for modern slap)
    -1100 (presence and projection, cut trough)
    -1500 (pitch definition, snarl)
    -2500 (bright, uppest mid bite)
    - 4000 (that 70' jazz with fresh rounds bass grind)
  5. topo morto

    topo morto

    Mar 22, 2010
    Won't a shelving EQ at 100Hz boost 40Hz more than it will boost 100Hz?
    superheavyfunk likes this.
  6. thanks guys! this info is very useful!
  7. sratas


    Dec 15, 2007
    Parma, Italy
    yes, it will, but a shelving centered at 40 hz with a rough slope will certainly not affect 100+ Hz considerably. useful for preventing speaker failure, but if I want a useful impact even on more audible frequencies i prefer an higher point, or a gentle slope wich affects even those territories...
    but this was only an example, just to explain...am I on exam?
  8. topo morto

    topo morto

    Mar 22, 2010
    No exam, just to provide clarity for the OP :)
  9. sratas


    Dec 15, 2007
    Parma, Italy
  10. Depends on your bass and your amp, but between 100 and 40, 40 is surely the most muddy. And i've heard soundguys say they cut everything below 70-100hz on the bass because that's where the kick drum sits, so having a control for 40hz seems kinda pointless for me.
  11. testing1two

    testing1two Gold Supporting Member

    Feb 25, 2009
    Southern California
    The common misconception is that the shelving EQs on these preamps are steeply sloped like a high-pass or low-pass filter when in fact they are not. In this application the shelving EQ has a fairly gentle slope (measured in dB/octave) which determines the characteristic of the boost/cut.

    For example, the EMG EQ circuit has a bass frequency centered at 50Hz but because the slope is gradual, adjusting the bass control affects frequencies as high as 800Hz! FYI- The EMG circuit has a 6db/octave slope.

    So the center frequency is only important in terms of how it affects the slope. The Aguilar preamp has a bass control centered at 30Hz which virtually no bass cab can reproduce but because of the slope it sounds great. The Glockenlang preamp has a treble frequency of 18kHz which is outside the range of most human's hearing but because of the slope it sounds wonderful and musical.

  12. DrumsAndBass

    DrumsAndBass Supporting Member

    Apr 7, 2011
    San Diego, CA
    Consider the 40 hz as first priority. The harmonic above would be 80 hz and that would also be a desirable frequency.
  13. yes i have an audere jz3 3band on another bass and i read the following off their website so i understand the center frequency is not the only and the most important factor, but i still wanted to clarify before i get something which makes matters worse anyhow the two band audere jz3 is also at 100hz so that helps knowing its not that frequency in specific!


    Two Band Version:
    • The Bass tone control is a shelving control.
    The single level can be increase or decreased by 13+ dB.
    The 1/2 variation frequency is at 270 Hz.

    • The Treble control is a shelving control.
    The single level can be increase or decreased by 14.5+ dB.
    The 1/2 variation frequency is at 1.4 KHz.

    Three Band Version:
    • The Bass control is a shelving control.
    The signal level can be increased or decreased by 12+ dB.
    The 1/2 variation frequency is at 120 Hz.

    • The Mid control is centered at 470 Hz.
    This is a wide bandwidth control meaning the control effects a wide range of mid band frequencies.
    The signal level can be increase or decreased by 10+ dB.

    • The Treble control is a shelving control.
    The signal level can be increase or decreased by 10+ dB.
    The 1/2 variation frequency is at 2.5 KHz.

    Our Specifications are a little different than many preamps:
    • The most important specs for a Bass or Treble control include the +/- variation range and the frequency at which the level changes 1/2 that amount. You can consider this to be the frequency at which the tone control effect ends.
    Several other preamps list a theoretical peak frequency change point. So a Bass control might be labeled as 40 Hz instead of specifying the 1/2 max change frequency points.
    We feel the 1/2 max frequency point is a more important real world spec because it will make much more difference to the player in how the tone control really feels. For example, the Bass tone control for our 2 band will feel bigger than the one for the 3 band. The level of max variation is the about same but the 1/2 max frequency point has been increased for the 2 band version.
    • Our Mid range frequency spec is more typical - the center frequency and +/- variation.