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Low pass a tweet?

Discussion in 'Amps and Cabs [BG]' started by kringle77, Oct 7, 2013.


  1. kringle77

    kringle77 Supporting Member

    Jul 30, 2004
    Massena NY
    Alot of guys want alittle extra top end that they can't get from a woofer so, they use a tweet to get it. But, that often is too much treble extension for many so, I was wondering if anyone has band passed a tweet from 3.5hz to 5khz, just to get some top end but, not to much sizzle? Maybe a 12 db bandpass?
     
  2. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    That's what a midrange driver is for.
     
  3. will33

    will33

    May 22, 2006
    austin,tx
    This^^


    In live sound, sometimes it can help to lowpass around 10-12khz because there isn't much left up there other than noise and hiss anyway, but that's done actively before the speakers.

    Here, yes, you coukd lowpass a tweet just like any other driver, but it's really using the wrong tool for the job. Unless you're shooting for some specific tonality. In most cases, just running a tweet from 3.5-5khz is pretty much a waste of a tweeter. Plenty of small cones can play that range.
     
  4. The VLE filter on MarkBass heads does exactly this.
     
  5. Bassmec

    Bassmec

    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    Most bass guitar amplifiers actually have active EQ circuits built in, so if you find you have too much high frequency information in your sound
    You can use that to curtail the excess HF.
    Even if you have a passive bass they are often equipped with a tone knob.
    Why would it be important to increase the impedance that the amplifier output sees at any one band of frequencies when it's a function you have already bought and paid for that conveniently operates at line level.
    A tube amp will be somewhat unimpressed at having to drive exaggerated impedance fluctuations other than those naturally occurring in attempts at a flat frequency response in crossover designs and the normal performance of the driven loudspeakers.:bassist:
    If you don't like a tweeter change it out for a unit that suits your bandwidth like a midrange unit?.:bassist:
     
  6. Passinwind

    Passinwind I am Passinwind and some of you are not. Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Duke has done something like that with the treble rolloff switch in the Thunderchild cabs, albeit not in that exact form.

    I just use a preamp with the treble control frequency up around that point. Often I am boosting a little, not cutting, if anything though. ;)
     
  7. will33

    will33

    May 22, 2006
    austin,tx
    The Thunderchild is one example but that's incorporated completely different than a typical bass cab tweeter. Large format horn, crossed over much lower, plus additional voicing filters, etc.
     
  8. Arjank

    Arjank

    Oct 9, 2007
    Above Amsterdam
    Yes and No
    Well, if it's a tweeter you'll likely want it to run up to 8 or 9khz (3.5-5khz would indeed make not much sense). A small mid can do that on-axis for sure but off-axis a tweeter has a much better dispersion. To surpress the "sizzle" a bit, a 6dB lowpass would do the trick. If the tweeter is 8 ohms just add a 0.2 or 0.3mh inductor in series with the tweeter, add a switch parallel to the inductor to turn it on/off. It's cheap and offers some space for experimenting. :)

    But, IMO I would just use the treble control on the bass or pre-amp.
     
  9. kringle77

    kringle77 Supporting Member

    Jul 30, 2004
    Massena NY
    The trick for me is to get a treble boosted signal to a 10" woofer so it will growl alittle. But, then you have too much going to a tweet. When you use an eq, you remove the top end from both drivers.
     
  10. will33

    will33

    May 22, 2006
    austin,tx
    Could try Arjanks inductor. In combination with an L-pad, might get you what you want. Just slightly bigger inductor should land somewhere in the neighborhood of 5khz.

    Your tweet would only be adding about 1/2 octave of extension though.
     
  11. will33

    will33

    May 22, 2006
    austin,tx
    The resistance of the inductor would be added to the tweeter impedance, but one that small shoukdn't be enough to mess with the l-pad.

    Cheap to try. Just doesn't seem to me you'd be gaining much. The tone knob on your bass basically is an adjustable lpf.
     
  12. BurningSkies

    BurningSkies CRAZY BALDHEAD Supporting Member

    Feb 20, 2005
    Seweracuse, NY
    I understand what you're going for. I use the same tactic on the lows with my Fdeck HPF3. I boost my lows then use the high pass to get rid of the extreme lows from the shelving.
     

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