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preventing the dirty great 50Hz rumble

Discussion in 'Hardware, Setup & Repair [BG]' started by nil, Jan 23, 2001.


  1. My reissue Dan Armstrong lucite bass has always had a problem with sub-bass tones messing with things. By that I mean there is alot of 50Hz rumble that's apparent, especially if you don't mute a string *absolutely*.

    Now, if I had a graphic EQ on my current amp, that'd be OK (killing the 50Hz completely helps), but I don't...

    It's more obvious when using the Bright Bass p/u (p-bass sound) than the Dark Bass p/u (gibson eb-0 sound).

    Does anyone have any recommendations that I could add to the bass' wiring (ie internal components) that could help me here, such as a crude 50Hz HPF?

    thanks!
    neil.
     
  2. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member

    It sounds like it would be cheaper, easier and more useful in the long run just to mute properly. This is really part of good bass playing and I have heard 4-string players who don't think they need to do it "rumble" - most multi-stringers soon realise that it's essential as there's nothing worse than a B string resonating and drowning everything else out!
     
  3. Bruce is right, as usual, good technique is the answer, not EQ. As soon as you start taking frequencies out, you start reducing the quality of your sound, particularly in the lower end. I dont know what level you are at, but a lesson or two on left hand and right hand technique from a teacher will get rid of your problem.
     
  4. Thanks for the replies, although i'm pretty sure it's not solely my technique.

    My level of playing isn't *too* advanced (although people in the past have asked if I was a session player), but my muting techniques haven't caused any problems when playing any other bass. Right-hand muting for me involves using my right-hand ring finger, 'cause I anchor above and not on the E string all the time. Left-hand muting just like everyone else.

    When playing my Rics, I never have any problems like this, it's just this Ampeg - there's definitely more real rumble (like REAL LOW, somewhere between 30-50Hz). Muting on this puppy often requires a left- and right-hand technique at the same time to stop the string completely. But muting isn't the only problem - these low frequencies are quite apparent during normal playing...
     
  5. Rockinjc

    Rockinjc

    Dec 17, 1999
    Michigan
    You could get a $400 dollar preamp with some fancy eqing, but the more you can do with your hands the better off you will be, even if each bass behaves differently.

    Free your thumb!
    jc
     
  6. Rockinjc: a Bass EQ may have to be the way ;) All i'm after is a piddly little HPF circuit idea to incorporate, even if it ends up being in a pedal form.

    I detuned the beast to BEAD the other day for a laugh, and surprisingly (for a short-scale, using standard guage 45-100 strings) it tracked remarkably well with the low B...except for those damn sub harmonics that gave my quad more of an exercise than it really wanted!
     
  7. pkr2

    pkr2

    Apr 28, 2000
    coastal N.C.
    Nil, I understand what you are trying to do but I don't believe a filter would be practical in your case. You can filter out the offending frequency pretty easily but unless you come up with a high Q, very narrow bandwidth filter you are going to remove some very important fundamentals at the same time.

    I built a circuit as a ham radio operator that was called a Q multiplier. They are used to seperate C.W. (morse code) signals. The L/C circuit components at audio frequencies tend to be pretty large physically. The one that I built was about the size of a shoe box. The capacitor, the inductor or both have to be adjustable in order to tune it to the proper frequency and it gets pretty gimicky. You would also have to cascade more than one L/C circuit to get the bandwidth narrow enough to be effective and selective.

    There may be some modern circuits that would do about the same thing although I'm not aware of one. The one that I built was in the 50's.

    Your time and effort may be better spent tracking down the problem and repairing it. You may be treating the symptom rather than the problem.

    Pkr2
     
  8. Since I replied (above) I have read a review of your bass, and it seems you may be justified in your concern. That bass seems to have an abundance of sub frequencies, and I think the answer may be to move on to something else. They do look cool, though.
     
  9. Marty Marty Marty! How dare you suggest I move on! :D

    Where did you find a review? I'd be interested in checking out what others said.

    Have you tried one out? A very interesting beast - heavy as hell, amazing sustain, and the neck and fretboard play sooooo fast! I found this one on a trip to the US last year, unplayed condition, and a good price...it was apparently given to Lenny Kravitz' bass player, who used it for a promo shot (never played it) and then flicked it on. At least it's probably the only one in NZ! :D

    As a sidenote, for alot of fat playing (ie reggae, dub, etc) the amount of sub can work in it's favour, but compared with my Ric in a rock setting it loses focus (ok ok, I know it's not a fair comparison!).
     
  10. spoolie

    spoolie

    Nov 30, 2000
    If your bass cabs are ported, stop up one (or more) ports with a small towel or something. It could sound like crap or it could cure the problem in certain rooms. I often do this at various venues and can sometimes clear up an offensive rumble without sacrificing bottom end. Sometimes is the operative word.