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Nasty Speaker Burp When Using A Pic

Discussion in 'Amps and Cabs [BG]' started by kdogg, Nov 13, 2005.

  1. kdogg


    Nov 13, 2005
    I run an SWR SM-500 through an SWR Goliath 4x10 and an SWR Son of Bertha 1x15, and I'm really digg'n the tone. However, last night at band practice, I noticed when I switched from using my fingers, to using a pick, on certain notes, the pick attack caused the speakers to produce a nasty sort of burp or pop sound. I stopped using the pick, because I didn't want to damage my speakers.

    Today, I'm going to try to track down the culprit, and I was just wondering if anyone else has had a similar experience? My eq is set pretty flat; a slight boost at 80hz and again at 200hz. I set my gain so that the clip light just barely flashes on my loudest notes, and my master volume is usually never above 10 o'clock.

    I'm not sure if the problem I was experiencing is due to a bad eq setting, overdriving the preamp stage, or the attack of the pick briefly overdriving the speakers. Maybe a combo of all three. I never experienced this problem with my old SWR Silverado combo, so I'm slightly perplexed. :meh:

    Any thoughts would be greatly appreciated.
  2. Eric Moesle

    Eric Moesle

    Sep 21, 2001
    Columbus OH
    When using a pick, kick in a compressor, it will help even out the peaks from using the pick. If you really dig your fingerstyle tone, don't alter your EQ settings and ruin that tone just for your picking tone.
  3. specplyrz

    specplyrz Banned

    Nov 11, 2005
    "When using a pick, kick in a compressor, "

    Why? Let me explain, except for a jetphase in the late 70's I have only played bass and amp. Period. I realize the value of flangers, compressors and such, by why "Limit" your tone and attack with a compressor.

    Two things come to mind here, 1) turn down.....2) get a powerfull enough system so that picking won't pop your speakers.

    When I play bass, I express myself through my tone...why would you ever want to compress, (limit) that expression?
  4. kdogg


    Nov 13, 2005
    As I mentioned earlier in my post, my master volume pot is usually never above about 10 o'clock, so I'm not sure that the problem is associated with the volume being too high. The head I use is 500 watts at the 4 ohm load I'm showing it, so I'm pretty sure headroom is not the issue either. When the full band is playing, two guitars, drums, and lead vocalist, I have more than enough volume.

    Are you saying that more power would prevent the popping? Could you clarify why you feel that is the case?

    Thanks for the tips so far.
  5. Fretless5verfan


    Jan 17, 2002
    I don't know what kind of compression you've been using, but with the compressors i've used i've never "limited" my tone or attack.
  6. specplyrz

    specplyrz Banned

    Nov 11, 2005
    well...OK...but a compresor "limits the high and lows" it usualy makes them equal. A great example of compression is to listen to Carlos Santana's album from a few years back when he sang with some different artists. He, I belive won a grammy for it. An incredible cd....except is was so compresed, all you got out of it was midrange. Horrible finalized product. Compresors were originaly made to make F.M. radio stations sound more even. The device boosted soft signals and LIMITED loud signals, so you would have a nice even band to broadcast out of your cheap radios at home and especialy in the car...since for most people, that is where their maximum exposures are/were. No they are used when you don't have enough power to reproduce what you are really playing.

    A compressor is just another fancy device to limit high signal gain output.
  7. specplyrz

    specplyrz Banned

    Nov 11, 2005

    Well see my other posts, but also, are you hitting your pickup when using a pick. I get very agressive when using a pick and my RIC neck pickup get hit now and then...giving of a poping sound.

    Try this experiment. Play your bass at normal volume with your fingers, then lay it down on the floor or a bed and pick an open string, downward, then upward. Is there any difference. Do you still get that pop sound?
  8. I believe all recordings are dynamically compressed, to 70db back in the old days for vinyl (not sure about CDs now) if you want a better example, listen to Physical Graffiti, now that compression was horrible!

    For bass, a nice 1:3 with a soft dbx160 ramp is nice, and almost undistingishable, either that or a hard limit, one or the other IMHO. The longer you play (years) and the more experience you gain the less youll need a compressor, youll become one with the "instrument" - pick/fingers, string, pickup, amp, speaker, room acoustics... all one.

    But for your problem with the pick/speaker, maybe try flattening out the bass EQ if you have it boosted. Bass will be heard louder 15 feet in front of the cab compared to right next to it, and sometimes a bass boost isnt needed.
  9. The Clap

    The Clap

    Jan 5, 2004
    Scottsdale, AZ
    Not really, compression doesn't inherently have anything to do with different frequency ranges. There are completely legitimate uses for compression in live bass rigs (the OP's situation is a good example), and bass tracks are always subject to compression in the studio.
  10. specplyrz

    specplyrz Banned

    Nov 11, 2005
    Mike and The clap...thanks for the replys....somthing to think about...never to old to learn....but still to stuborn to act ;)
  11. Eric Moesle

    Eric Moesle

    Sep 21, 2001
    Columbus OH
    When you play with a pick, you are usually (not always, but usually) creating "spikier" signals than when you pluck with the much softer pads of your fingers. Its those additional spikier levels that are likely causing the "burping" you are hearing. A gentle setting on a quality compressor/limiter will solve that problem and keep things just under that burping threshold.

    ALL professional recordings nowadays have compression on the bass tracks, and most other tracks as well. You only NOTICE the compression if it is done poorly or is done purposefully for a desired effect . . .
  12. Try turning down your pre-gain, or use the -15dB (or whatever) pad on the input, or turn down your bass a bit, you could just be clipping the input or pre of the amp
  13. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    True.... for most compressors and limiters..... sort of....

    The compressor or limiter generally responds to the level of the largest signal........ at the time. And it responds ELECTRICALLY, not ACOUSTICALLY.

    That means that it will "squish down" the signal based on the biggest amplitude part, which usually is the low end. It takes the harmonics down with it. There usually isn't much if any compensation for the way you hear.

    But since your ear doesn't respond the way the compressor does, that may make the low end drop off due to the "fletcher munson" effect that has been mentioned a few times..... Since your ear is more sensitive to the harmonics, they seem louder, causing an apparent low end drop off.

    Also, if you pick or string pop a lot, it may respond to those peaks, and hold down the whole signal. That's more for limiters, which tend to have a faster "attack" or response time than a true compressor.

    Again, the highs seem louder, because you hear them well, and there are more of them to start with, while the lows can drop off due to your ear response.
    And, it can make the amp sound really wimpy if it tries to keep those short peaks down under clipping.

    Another effect is if the compressor is AFTER some EQ. Then it can act as an "EQ magnifier" , because whatever you boost has the most influence on the level set by the compressor or limiter.

    It pays not to "get into" the compression or limiting too far, use the least possible.

    Just let it take care of high levels, and have it stay out of the way otherwise.