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Maximize the Thump

Discussion in 'Amps and Cabs [BG]' started by Alexander, Jan 8, 2004.


  1. Alexander

    Alexander

    Aug 13, 2001
    Seattle, WA
    I like the thump of my PBass and was happy to get a similar sound with my Tribute L-2500. I'm wondering what I can do to bring this thump out even more. People have said to get more growl, you need to boost at around 800hz. Is there any way to bring the thump out more by tweaking?
     
  2. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    Shouldn't this be in basses...or setup?

    Anyway, how about a low mass bridge (like a P) and only 4 neck screws (also like a P)?

    I suppose Thump is like anti-sustain. Undo sustain adding qualities and you could enhance thump...

    How about lowering the pickup(s) and/or raising the action or adding relief?
     
  3. Alexander

    Alexander

    Aug 13, 2001
    Seattle, WA
    I am more asking about changing amp settings to maximize thump, which is why I posted this here. I've read a lot about how to hot-rod a bass to get there, but I don't want to do that with my L-2500 (I want to keep it stock and flexible to other good tones - of which there seem to be many with this bass). Thanks for your advice, though.
     
  4. Frank Martin

    Frank Martin Bitten by the luthiery bug...

    Oct 8, 2001
    Budapest, Hungary, EU
    Well, use the thumb and mute the notes with it to prevent it from ringing out; use more of the neck-area pu (with a P its the P, obviously ;) ), add more bass and more lower midrange - or thats how i would do it...
     
  5. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    Oh...I completely misunderstood what you were saying in the last two sentences of your initial post.

    You'd get thump from a sealed cabinet that is too small for the speakers inside. If your cabinet has a port, try plugging it with some dense foam or even a towel.
     
  6. drd07

    drd07

    Jan 19, 2003
    Thump - Throw on some flats!
     
  7. The 0x

    The 0x

    Aug 24, 2003
    Timonium, MD
    And soak them in grease! :p


    (DON'T!)
     
  8. Woodboy

    Woodboy

    Jun 9, 2003
    St. Louis, MO
    to me seem like two different things. Thump is quick development of the fundamental and quick decay, like a kick bass drum. Growl is the upper partials (harmonics) bumping into one another. Mutant is right about using damping techniques and boosting the bass. This will give you the quick boom and decay you need for thump. I don't think plugging up the port is a good idea. The speakers are designed for a certain vent size and amount of back pressure the air in the box provides. You would be totally negating the efforts of the speaker designer by doing this. Flats will help your thump, but not your growl.
     
  9. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    Precisely my point about plugging the ports. The cabinet designer was probably aiming for a full range response with as deep a bass response as the woofers and economic would allow.

    Amps like the Ampeg portaflex, noted for its thump, has a 15 in. speaker in a smallish box enhancing the thump.

    Same thing with the first generation Avatar Compact 15 cabinet, the little cube (very Bag End like) with a Kappa...not a lot of low bass but lots of thump.
     
  10. HeavyDuty

    HeavyDuty Supporting Curmudgeon Staff Member Gold Supporting Member

    Jun 26, 2000
    Suburban Chicago, IL
    BillyB, now you have me interested in what would happen if I plugged the port on one of my pair of Bag S15-Ds, and left the other open...
     
  11. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    You will effectively lower tuning frequency of the cab. From a frequency response point of view, this will raise the -3dB point. However it will result in a much shallower roll of in the low end. The result will be a bigger area under the curve in the region below F3 and an apparent increase in bass = THUMP.

    My concern with this is the changes to driver excursion that will result. You may be introducing unwanted additional speaker cone movement and therefore unwanted distortion or worse. If we had ahe speaker's T/S parameters we could run a simulation.
     
  12. redneck2wild

    redneck2wild

    Nov 27, 2002
    Memphis, TN
    If you have a local music store that has Aphex equipment, you might try one of the Bass Xciter pedals or a rack mount Aural Exciter.
    The Big Bottom portion of either can be used to add Punch without affecting your tone. You set a frequency and everything below that frequency briefly "swells" a small amount, giving you additional punch.

    Boosting your Low-Mids can also give you additional thump (80hz-120hz seems to work for me), but it affects your tone.
     
  13. HeavyDuty

    HeavyDuty Supporting Curmudgeon Staff Member Gold Supporting Member

    Jun 26, 2000
    Suburban Chicago, IL
    I'm pretty sure Bag End offers a port cover as an option for my cabs, so it's probably OK from an engineering standpoint. I'll give my guy at the factory a call on Monday and see what he has to say about excessive driver excursion.
     
  14. HeavyDuty

    HeavyDuty Supporting Curmudgeon Staff Member Gold Supporting Member

    Jun 26, 2000
    Suburban Chicago, IL
    Forgot to post back!

    Per Dan at Bag End/Modular Sound, no prob in sealing the port in a S15-D. As a matter of fact, one of the guys at the factory does that in his PA rig to get a (IIRC) 100Hz bump.

    I'm going to have to try and find something to temporarily seal one of the ports and see what happens. Pray for me.
     
  15. ihixulu

    ihixulu Supporting Member

    Mar 31, 2000
    getting warmer
    Please report back with results and impressions.

    oh yeah... Amen for you, Bro.
     


  16. trace-elliot had covers for their ported cabs
    both open:F3 45hz
    both closed F3 55
    one open :F3 35
    it sounded pretty good in the 2x15 i had when closing the upper one and opening one port in the bottom
     
  17. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    I would think that plugging a port would increase the internal (air) resistance to motion by the speaker cone, and result in less cone movement per watt input.

    P.S. The BE S15B-D comes with a plug for its port.
     
  18. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    yes but at what frequency are you talking about? Port activity if frequency dependant. Speaker cone movement is at it's least at the frequency the cabinet is tuned to. Ironically that's also where the speaker cone is under the most stress because the air in the cab acts like a spring. Make the spring too stiff and the speaker can't function properly and can even crease the cone if the situation is bad enough.

    Excursion is actually quite complicated and I've got a lot to learn about it yet.
     
  19. I've got an L2500. Select the neck pickup, switch it to series and stay passive: BIG thump.

    I wouldn't call 800 Hz "growl." That's more upper midrange snarl and if overused, honk.

    Boost around 250-300 Hz for punch and 80-100 Hz for thump while cutting the upper mids (1-2.5 kHz). Leave some extreme highs to avoid total mud, but it's better to cut them at your amp and boost them on the L2500, which has some of the best voiced EQ I've ever heard on a bass.
     
  20. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    Thanks, Pete.