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Question about amp compatability and a current "hiss"?

Discussion in 'Amps and Cabs [BG]' started by yomchi247, Jun 26, 2005.


  1. yomchi247

    yomchi247

    Sep 6, 2004
    Hi, I'm currently using a Hartke 7000 head through a SWR Goliath II Jr(2x10), and a SWR Son of Bertha(1x15) cabs

    I've been playing bass for a while, but I've never really been good with electronics or troubleshooting things like this, but my problem is this: When I play my Spector 5 string through this rig, I get this annoying hiss. Also I play it turned up to at most 3, and if I turn the bass up very much at all the speakers move like crazy when I play the B string.

    Now I don't know if the hiss could possibly be bad speaker cables? I've never dealt with these problems before, so I'm just looking for any kind of advice. Is this head compatable with the speakers? I am running it bi-amped by the way.

    Any help would be greatly appreciated...I don't know if this is enough info for someone to help, but if you need more, just ask :)
     
  2. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    That hiss is semi-conductor noise, and if you have a tweeter it can be very obvious. I put a downward expander into my 3500 to mute the output when not playing it bothered me so much; while playing you can't tell the difference. Running the master at a lower level and the input higher will help, and have the level on your bass at full. The other problem is called overexcursion, your speakers aren't able to handle the power you're putting into them down there, especially the tens. Lower the 32 Hz and 64 Hz EQ sliders as far as you must to eliminate it. If you can't get adequate volume or tone after playing with the EQ you should consider a better speaker to handle the lows.
    Cables have nothing to do with either symptom.
     
  3. Kael

    Kael Supporting Member

    Dec 26, 2004
    Oklahoma City
    Hartke heads have always had hissy high end. I think that Spectors use boost only preamps, so that would also boost your highs exacerbating this. Take the 8Khz fader on the graphic EQ and start cutting till it goes away. With tweetered cabs that might mean cutting almost all the way down.

    The speakers moving like that could be a product of too much low boost in the EQ. Don't know how you have your EQ set, so I can't say.
     
  4. yomchi247

    yomchi247

    Sep 6, 2004
    ok, I'll try those things tomorrow and see how they work. I plan on upgrading amps in the future, but right now I'd just like to get the most out of this rig.

    Thanks for the replies :bassist:
     
  5. yomchi247

    yomchi247

    Sep 6, 2004
    also, how does a downward expander work? and how much are they? because I'm in the same boat...I can't stand the hiss when not playing
     
  6. yomchi247

    yomchi247

    Sep 6, 2004
    a
     
  7. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    A downward expander turns off the signal once it fades below a certain point, turns it back on again when you play. Sort of like a noise gate, but better. I built mine from scratch and installed it in the amp. They can be found in many compressor/limiters. A simple noise gate may work for you as well, but not one on the input, it works best in your effects loop.
     
  8. Kael

    Kael Supporting Member

    Dec 26, 2004
    Oklahoma City
    That does sound like a noise gate. Is the difference between a downward expander and a noise gate in the means by which they each accomplish the same task, or do they accomplish slightly differing tasks?