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"Thump"-sounds when amplified

Discussion in 'Amps, Mics & Pickups [DB]' started by MichaelSC, Apr 2, 2006.


  1. Hi.

    I know that this probably has been discussed several times, but since i suppose the answer might differ depending on the specifications of the setup, I've chosen to make a new thread.

    I have just bought a shadow pick-up (SH SB-02, piezo-pickup, same type as the bass max, just lower quality i quess), and when I wire up my bass and play, it has these "thump"-sounds when pizz'ing, especially from the low c and down - in my opinion I have to much "pizz-sound" and too little tone. It is also difficult to get a decently authentic and soft tone (though this might be due to the p.u.), and I can't really EQ it away, since i have some bad feedback-problems. If it is called feedback, when using piezo.

    You have some suggestions?

    I (unfortunately) play a 120W quitar amp of the brand "Stingray", and run the signal through a Boss CEB-7 equalizer-stompbox.

    Edit: typos
     
  2. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    Nothing can be diagnosed until you get a preamp, or are assured that your pickup is feeding an input impedance of at least 1 MegOhm. After that is settled, then it's just a fact of life that no two basses are the same in terms of what pickup sounds good. Finally, if you are using a guitar amp, when you play loud low notes, then you are likely to be overdriving the speaker.
     
  3. I know that a preamp is unnecessary with my pick-up so that can't be the problem. And when i play low notes, the amp doesn't peak ord tend to make an "overdrive"-effect, and I have used the amp with my electric bass to with no great problems.
     
  4. mje

    mje

    Aug 1, 2002
    Southeast Michigan
    fdeck may well have the answer. There are many possible sources of the proble. The shadow bass pu is simply a piezo bender coated with pvc. If it's not in there firmly, it can decouple and rattle at low frequencies. How do you have it mounted?
     
  5. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member In Memoriam

    I'm surprised that nobody has mentioned that a 120 watt guitar amp is just not going to cut it for amplifying Double Bass - most guitar amps are "coloured" and emphasise a certain part of the audio spectrum to make guitars sound better.

    For DB you need amplification and speakers that cover a wider range and go down lower - plus you need more power to amplify bass frequencies without distortion.
     
  6. Yes, I probably had expected a response like that. I am trying to get my old bass rig back, but unfortunately it's with a 15" and a 12" speaker, so I'm considering investing in a Behringer BB 210 Classic Tone (http://www.behringer.com/BB210/index.cfm?lang=ENG)
    But would you consider this to be a good investment? As far as I've understood from surfing the rest of the archive is that with DB fairly little speakers would be an advantage.

    If i get a feedback-killer would I then be able to use my EQ without having to worry about feedback?

    Edit: changed link
     
  7. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member In Memoriam

    My personal opinion is that what you are referring to would be a good rock bass guitar setup - but not really suited to a good Double Bass sound.

    Also - if you are trying to get a lot of volume from DB with such a set-up - then feedback is going to be a peotential problem.

    PS - it will help people to help you, if you fill in your profile!!
     
  8. Okay, but then what would be a decent cabinet for both EB and DB at an affordable price?

    Okay, but what might a solution be? Can't a feedback killer make any difference?

    By the way, I have filled in my profile now, hope that'll help a bit.
     
  9. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member In Memoriam

    I don't know - suggest you search this forum.

    Err...is there one ? Buy an EUB? ;)

    I didn't know there was such a thing! :p

    Good!
     
  10. bolo

    bolo

    May 29, 2005
    Apex, NC
    Hi MichaelSC.

    When I first read the title of your thread, I thought of something else entirely.

    When your plucking finger comes to rest on the string below the one you just played, does it thump?

    When I first started playing upright I had a BassMax. Sometimes I would hear this weird thumping, especially on fast songs. I didn't know much about right hand technique for DB at the time. I eventually discovered after I plucked a pizz note, my index finger would thump into the next string. I think both types of wing-mounted pickups that I have used can sense this type of string vibration quite convincingly and can send the resulting signal to your amp.

    Nowadays I pluck the string quite differently, and I know how to lessen or eliminate that type of thumping sound.

    Just another far out thought.
     
  11. No, I don't quite think that might be the problem (though I do hit the string below), because when i pizz in a more classical kind of way, where the is weaved away from the strings as if hilding a bow, it still makes the sound.

    Moreover, it only makes the sound on the lower strings (A and E)
     
  12. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    Have you tried muting the afterlengths of the strings? This usually cleans up a lot of amplified ugliness. To test for this, have a friend hold the afterlengths tightly while you play and see if the sound still happens.

    Learning to amplify a doublebass is a lot like learning to live with an older VW....
     
  13. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member In Memoriam

    I agree with Chris's last point - I've found all sorts of differnet problems amplifying DB in different rooms - but I'm pretty sure I'd have even more if I was using a Carlsboro Guitar amp....:meh:
     
  14. Yeah - I've heard about that, but how is that done practically?

    Hehe... point taken:bag:
    as mentioned, I'm working on getting my bass rig back to my place (Have I mentioned that?)
     

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