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Where are the Low Freq 12's?

Discussion in 'Amps and Cabs [BG]' started by playswhatpays, Jan 24, 2012.


  1. playswhatpays

    playswhatpays

    Jan 24, 2012
    Fargo, ND
    Hello Talkbass! I'm brand new to your forum, although I've read it for years.

    I'm trying to find a good replacement for my SWR Workingpro 12. It has been 10 below zero and I hate dragging in my Ampeg set up in for practice, only to wonder if the speakers have warmed up enough not to shatter. The workingpro is a very capable practice amp, but the speaker ripped on the surround. In looking for a suitable replacement, I'm finding nothing beyond mid 40hz for usable low frequency. This is a problem if I want this amp to let my 5 string sing.

    There will be the limitation of my cab, but I really want a speaker capable of producing true notes. So my question is...

    Where can a guy get a 12" speaker that goes down to the mid 30hz level?

    Has anyone tried rocking a subwoofer? Eminence Lab 12 is looking really good to me, but it drops at 1k. Would I miss the gap to my tweeter, or would the super phat lows be worth it? What do you think?
     
  2. DukeLeJeune

    DukeLeJeune rational romantic mystic cynical idealist Supporting Member Commercial User

    Nov 24, 2008
    Princeton, Texas
    Owner & designer, AudioKinesis; Auth. mfg, Big E (Home Audio only)
    The first overtone is more important than the fundamental, as far as bass guitar amplification goes. Going an octave deeper to get the fundamental of low-B is a rather expensive proposition in terms of not only displacement, but also box size, efficiency or both.

    You'll need to move four times as much air to push the low end one octave deeper at the same SPL. This can come from increase cone area, increased excursion, or some combination thereof.

    If you want to maintain the same efficiency, you'll need to increase the box size eight-fold. If you want to keep the box size the same, you'll lose 9 dB of efficiency. Or, juggle these tradeoffs to find a live-with-able compromise.

    Finally, even if you could get it, are you sure you want full power output down to the mid or lower 30's? South of 50 Hz or so is normally kickdrum and keyboards/synth territory.

    A subwoofer is generally not a good choice for a bass guitar speaker, but a subwoofer can theoretically be added, to augment your bass cab, and extend the low end that extra octave or so.

    If you still want to go in this direction with a bass guitar cab, I suggest you look at Acme. A woofer retrofit in your present cab is unlikely to do what you want because it takes woofer, box, and port, all optimized and working together properly, to take you down into the fundamental region. Acme cabs are properly designed to go much deeper than normal cabs, and they trade off efficiency to do so.
     
  3. lomo

    lomo passionate hack Supporting Member

    Apr 15, 2006
    Montreal
    Duke, it's always a pleasure to hear your clear, factual explanations. Thanks!
     
  4. Bass Unique

    Bass Unique

    Nov 3, 2011
    Wiltshire
    You need to either move more air at source (seeing the cone as a piston) or match it better to the air - a horn would do this very well but there is still a size trade off and it would be huge at 30 Hz.

    It can also be done by air-mass loading a smaller volume box - the resulting peak pressure inside the cab increases with port and cone both driving in and out together. System resonance can also drop slightly mimicking a larger box at the low end. This results in more air movement at a port - not the cone (if it can provide enough driving force).

    Don't forget, once you have tuned a system port to resonate it will not require a lot of cone movement and nearly all the bass energy comes from the port. If you can broaden that resonance (or combine at least two) over a wider frequency range and add enough air mass within the port (and cross sectional area to cope with the movement with out significant losses), cone excursion drops and there is little loss of efficiency.

    However, do it wrong and you get a high output at one frequency which is still high efficiency but not usable for guitar (probably ok for a boom box in a car though!).

    The energy has to come from somewhere so this type of design (similar to the hybrids I work with) requires good power handling of the driver as with less cone movement over a wider range, temperature can increase.
     
  5. KJung

    KJung Supporting Member

    Per the comments above:

    1) Most of the published spec's on cabs are a bit 'loose and bogus'. For example, is that 38hz -3db or -10db. Pretty sure it is -10db.

    2) It isn't about the actual tuning IMO (40hz, 50hz, 33hz, etc.) but rather about the mechanical properties of the driver that allow you to put out a reasonable amount of true bass (i.e., 45-80hz) without the driver crapping out.

    3) The idea that you need to design an entire system around reproducing the fundamental the lowest few notes on the B string of a 5 string makes little sense. Good solid performance with a -3db at around 50hz with good mechanical specs with give you a powerful, articulate, full tone all the way down to the open B IMO.

    4) The Acme cabs actually are tuned to reproduce the fundamental of the open B string reasonably well (the little Acme Fullrange and Flatwound are probably the lowest tuned cabs around), but there is a cost to pay (low efficiency, and relatively low max volume, with the need for high passing, etc.)


    To the OP, the real issue with getting a full, deep tone from a little box is to have a driver that can really handle the wump. Most 12's sound fine, plenty deep and full at relatively low volumes. However, when you push them, that mechanical thing is the limitation, with the driver farting out because it runs out of 'piston' capability.

    There are a few very impressive 112's out there for the 5 string player... Duke's Thunderchild112, Roger's ML112, the fEARful 12/6 cabs, the Acme 112's (if you know what you are getting into with them). In a production cab that is available retail, the Bergantino HD112 is a good choice if you don't mind a bit more weight.

    IMO. It is pretty cool that a 5 string player now has the ability to get a pretty darn good tone on a medium sized gig with a very small cab:bassist:
     
  6. I believe he's looking for a raw replacement speaker for his SWR..
     
  7. You might want to test out a Mesa Scout Combo or even just the Radiator 12 Extension cabs. They're ported and have a passive radiator on the bottom that Mesa has tuned very deep. I never have a problem hearing my B string and often roll a little 40Hz back off the amp to compensate for the seemingly huge bottom that little Neo equiped cab has.

    If this is the case you may want to try to model an Eminence Deltalite 2512 in your SWR's dimensions. It's a little backwards but you should get a good idea if it will work before you buy it using a box design software. I experienced an amazing upgrade in low end extension of my SWR Baby Baby Blue 110 Combo when I swaped the original P.A.S. driver for a Deltalite II 2510.
    Here's some info:

    http://www.talkbass.com/forum/f15/what-program-do-you-use-match-speaker-given-cab-838483/


    This too:

    http://www.talkbass.com/forum/f15/upgrading-my-swr-baby-baby-blue-ii-110-combo-long-w-pics-839261/
     
  8. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
  9. KJung

    KJung Supporting Member

    Ah, that is more complicated. That box is probably not the appropriate size and tuning for a more robust driver.
     
  10. Coolhandjjl

    Coolhandjjl Supporting Member

    Oct 13, 2010
    Appleton
    These have been the most informative replies I have read here in a long time. As Sgt. Joe Friday often stated Just the facts Ma'am.

    I'll add that frequencies 40hz and below at stage/backline volumes can be nauseating. Fine for pre-recorded music in your living room with your hi-fi or home theater, but not for live music at concert volumes.
     
  11. Bass Unique

    Bass Unique

    Nov 3, 2011
    Wiltshire
    Two points on this:

    1) This is Greenboys waterfall explanation showing that the fundamentals are less important than the 2nd. However, GB is one of the few people offering good reproduction of fundamentals in his cabs. (contradiction?)

    2) Although the fundamental level is lower, having it or taking it away completely changes the scale of the sound. It's the difference between a big stack and a small combo when it comes to the fullness of the sound. If you can add more of it to a smaller box, it sound bigger for any given volume level.
     
  12. KJung

    KJung Supporting Member

    Actually, the 15/6 cabs I've played based on the amazing 3015LF driver aren't tuned particularly lower than most other cabs. The difference is, IMO, that the driver can actually pump out a good honest 45hz or so without compressing at moderate and even high volumes.

    It isn't so much about the low end extension as the mechanical properties of the driver, so that when you dig in and turn it up, that second harmonic of the B string doesn't compress and turn to mush. IMO and IME.

    With a smaller box, low end extension is not as much a problem as just pushing enough air at those frequencies (pure volume), even with the 'super 12's' that I often rave about.
     
  13. Bass Unique

    Bass Unique

    Nov 3, 2011
    Wiltshire
    I agree that a good driver is required. The LF series seems to do the job in terms of depth. The 12 actually goes a bit lower too but less output.

    No point in using a poor driver in any "good" design. If it is cheap, it would sound cheap.
     
  14. Doug Parent

    Doug Parent Supporting Member

    May 31, 2004
    San Diego, Ca.
    Dealer Nordstrand Pickups.
    Just a thought, have you considered replacing/reconing the driver in the SWR? That's going to be a straightforward solution that will restore that combo's performance if you think it's adequate for your needs and useful also if you decide to sell it. (?)
     
  15. BurningSkies

    BurningSkies CRAZY BALDHEAD Supporting Member

    Feb 20, 2005
    Seweracuse, NY
    The fEARfuls also have something that makes the lows that it can produce more palatable that many other cabs. Namely, the lack (or great reduction in) speaker based distortion. They're so much more 'clean' than other cabs that often you don't realize how loud you're getting. I agree with what you say about the second harmonic on the B, this is what also makes the limits of some amps stand out. Its one of the reasons I stopped playing a LMII with my rig...when it gets to a certain output level it's all low end compression, then it also provides some distortion in the mids that the fEARfuls didn't mask like other cabs I played with that amp.

    That said, using a bass with a 37" low B means I have more useful content down lower than most 34" scale instruments.
     
  16. KJung

    KJung Supporting Member

    Not sure if scale length would have any impact on actual frequency content. It would, of course, allow for a lighter gauge B string while keeping similar tension of a thicker string. I guess this could help a bit with limiting the strange overtones and intonation issues that you can run into with a very thick B string. The biggest E string I've ever heard (i.e., fundamental output) comes from my 30" scale Mouse!

    Also, that 'clean' sort of thing can be a blessing and a curse. Somethings, the various distortion patterns of speakers (and amps) is where the magic is. Just depends what tone you are going for IMO.
     
  17. tombowlus

    tombowlus If it sounds good, it is good Gold Supporting Member

    Apr 3, 2003
    Fremont, Ohio
    Editor-in-Chief, Bass Gear Magazine
    +1 to all of those. These would be my recommendations as well.

    I'll also add that if this cab meets your tone goals, the Orange SP212 is also pretty darned impressive. It's heavier than the rest (it is a 2x12, after all), but about the same size. On paper, the isobaric loading of the SP cabs seem to have more drawbacks than advantages, but in actual use, they are amazingly full and deep cabs for their size. Moreover, they have a different tone profile, which may appeal to some, but not so much to others.

    For most players, though, the cabs Ken listed above are going to hit closer to the mark. Of course, there is a lot of variation amongst the cabs listed, so a heavy dose of YMMV is in order.

    If used cabs are not available, and these cabs are too expensive new, then I'd say it's also worth considering the GK Neo112-II and the new Genz-Benz Focus 1x12. These cabs will not quite match the performance of the cabs listed above, but they are darned good and excellent cabs for the dough.
     
  18. greenboy

    greenboy

    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    Just for clarification, there are boxes tuned at 45 Hz that have practically no capability down there, just as there are boxes at that same tuning whose driver/box alignment allows a higher sensitivity and acoustic output.

    Some cabs that are really shy of low bass output with such a box tuning can keep the driver from unloading so easily - though it also impacts their power handling and acoustic output in the passband.

    Two45HzTunings.

    As always viewing a single number in isolation doesn't really tell one enough.
     
  19. Bass Unique

    Bass Unique

    Nov 3, 2011
    Wiltshire
    It only impacts the power handling / excursion at higher frequencies (60 to 120Hz probably) if there is not other method of cone control. Utilising a second resonance will control the speaker in this region too giving great mechanical control and lower distortion across the whole range.
     
  20. greenboy

    greenboy

    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    That is part of the actual pass-band, is it not?

    There is. They call it "EQ". Any player may simply at their whim reach over and turn down the region. Nowdays it may also enacted in conjunction with multi-band limiting via DSP - or even tailored voltage-sensing contouring.
     

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