Mid Freq?

Discussion in 'Pickups & Electronics [BG]' started by emre03, Sep 16, 2003.

  1. emre03


    Sep 18, 2000
    Sorry guys i know i sound like an annoying newbie but i never played a bass with midrange control before...
    What does a midrange control knob add to a 3-band eq?How does it change the tone and how does it change the freq you selected?Does it let you control the hz you selected(using the midrange boost-cut knob) and leave the other hz alone?What is its differences with a 4 or 5 band eq?)are there any five band eqs?)
    And for a midrange maniac like me what kind and brand of eqs would you recommend?(3b with mid control or 4 band(or 5 band if there is one))
    And what does a 50k push switch do (also a 50/500k thingy). And what is a paramethis eq?
    Sorry for the many questions i asked but i'm planing to replace the pickups and electronics of my two basses and i didn't understand anything from the previous threades i read...
    Thanks a loT...
  2. Okay, heres my attempt at some answers.

    The midrange selector knob allows you to select what frequencies will be boosted or cut from the signal. I don't know precisely how it works electronics wise, but I'm intersested in finding out if anyone can fill me in.

    The number of bands in the EQ is just the number of built in frequencies that are boosted or cut, ie you'd have lows (around 50Hz), low-mids (200-400Hz), high-mids (500-1kHz) and highs (3-5kHz) with a 4 band. 5 will have something similar but with another frequency to boost/cut.

    For on-board preamps, I don't know of more than 3 bands, just for ease, otherwise you get heaps of knobs cluttering up your bass. You can get a lot of equalisation options on a lot of off-board pres, or if you you can buy some with about 20 bands, like what you can get for sound desk operations.

    Dunno what the 50k push/pull will exactly do, cause I don't know what device you are talking about. It'll either act as an instant boost/cut to a certain level, or in some cases it will act as the selector for the mid boost/cut (OPB-3 kinda thing).

    I'm not entirely certain about what a parametric EQ does precisely but heres my take. It works like a regular EQ but you are able to sweep the frequencies rather than being bound to certain limits, it makes it more versatile.

    My recommendation: Up to you, with a 3 band you have pretty much all the options you'll need. If you really want options an off board EQ thingy is probly more down your alley.

    Josh D
  3. David Wilson

    David Wilson Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    as you say, a lot of questions :)

    daveze, some good answers there. I'll add my own.
    It lets you control the frequency being cut/boosted, instead of it being fixed at a certain freq. So, you could have boost on a low mid freq setting (something in 250-400hz range) if you're looking to cut through more. Or, put it up to a higher frequency (something in 650-700hz range) and cut midrange for a scooped slap sound.

    The only preamp I can think of that comes prewired with a mid freq select knob is the U-Retro. Other preamps come with switches to let you change the frequency. Aguilar OBP-3 can switch between 400hz and 800hz, or can instead be wired with a control to select the frequency. Bart 3 band pre's can switch between 250/500/800hz. Demeter preamps also have this option. I've had experience with the URetro, Bart and Aguilar preamps. While the U-Retro gives you more midrange flexibility, the Aguilar and Bart frequency select options give you plenty of tonal choice.

    I haven't seen any five band onboard eq's, there are some three band eq's that also have an extra 'boost' switch to boost highs - like the J-Retro/U-Retro.
    it refers to impedance (resistance) of potentiometers, which are the controls you use to adjust volume,bass,treble etc. Generally, passive pickups have 250k or 500k impedance pots. Active pickups usually have something less than or equal to 100K.

    A push switch is just what it sounds like, a switch. What it does is up to how it's wired. In many preamps, it's wired so that when you pull the knob up the preamp is bypassed. This is to save you when a battery dies. In the SD Basslines preamps, it activates a slap eq contour.
    A non parametric eq is the standard row of faders with cut/boost on fixed frequency centers and q (bandwidth - i.e. how much of surrounding frequencies are affected by this). Generalising, you use a larger q for boost eq and a small q for cutting

    A fully parametric eq will let you pick the center frequency, bandwidth, cut/boost amount. You rarely see parametric eq's with more than 5 sets of controls, as this is generally more than enough to do the sound shaping you need.
  4. emre03


    Sep 18, 2000
    Ok so you can control only one freq at a time with that mid freq knob, Is there any 4 band eqs with 2 mid freq knobs :D
    I have an offboard eq on my amp but it doesn't seem like like the real thing. You just change the output, its just like an ugly woman wearing makeup :)
    Did I get this right?: does a paramethic eq let you control more freq with one knob (like 5 freq with treb knob, 6 with mid knob...)and can i select which freqs i like to control with each knob?
    And which company has parametic eqs i can buy?And also which company has 4 band eqs?(and please write their urls if you know them)
    Thanks allready....
  5. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    I don't know if there are any basses with a semi-parametric mid (with which one knob controls the frequency and the other controls the boost/cut). Seems to me somebody ought to make one. My Zon Sonus has a three-position mid frequency switch that sort of does it, with a separate boost/cut pot. My Lakland 55-94's have internal dip switches that allow you to set the mid control at 250, 500, 700 or 850 hz, if I recall correctly. There's no instant access outside the bass, though. I've heard of people having Dan make a mod to put a frequency pot on the outside.

    For what it's worth, semi-parametric EQ allows you to control the frequency center and gain of a particular frequency band. Fully-parametric EQ lets you control not only those two parameters, but also the width of the frequency band around its center (the "Q" control). Using a very narrow band enables you to "notch" out an undesired frequency and attenuate it to oblivion. Great for feedback control and such.

    Here's a dandy little 5-band semi-parametric EQ that might suit you. Supposedly one of the best made.

    Raven Labs True Blue EQ

    Here's one for sale.


  6. John East

    John East Commercial User

    Jan 10, 2002
    Oxford UK
    Owner of East Tone UK Ltd
    In case you're not aware of this one:

    My Retro pres (J-Retro for J Basses and U-Retro - universal rear mount) have semi-parametric mid, or mid sweep. It does more than mid band I guess, the sweep is from around 150Hz - 3kHz. So there are a good number of basses out there with my mid sweep.

    See www.j-retro.co.uk

    > Dan make a mod to put a frequency pot on the outside.

    Dan uses some of my pres in the Laklands. (In fact he told me he uses them in his personal basses, which I'm really very pleased about!)

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