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Small Sealed 1x12: Best Driver?

Discussion in 'Amps and Cabs [BG]' started by voided3, Apr 25, 2018.


  1. voided3

    voided3

    Nov 11, 2008
    I'm considering putting together a small sealed 1x12" bass cabinet that'll be about one cubic foot in internal space. I did some searching and it seems that the best readily available driver option would be the Eminence Beta 12A-2, though the "small sealed box" cabinet design associated with the driver (also about one cubic foot) calls for a high pass at 120 Hz and has an F3 of 92 Hz. I'm guessing the power power handling will go way down from the quoted 250 thermally limited watts if I just plug a bass head into it sans HPF and bump up the low EQ a hair to fill out the sound.

    Are there other driver options that would work well for a sealed cabinet like this for bass and realistically handle at least 100 watts, or is the Beta the best bet? Should I just go for a ported design instead?
     
  2. Ported and sealed cabinets both have a bit of a different mojo. Though for the same given driver, and bass extension, a sealed cabinet will probably be smaller than a ported one - but the ported can be made to have a lower extension and will have more bass. Not to the extent of one being a subwoofer and the other only being good for mids, but it's a general trend. With that being said, I can see the beta doing well in a reasonably small cabinet - I know there's a ported 212 design on here that uses them, you could just half the size and ports of the thing and make a 112 from there. I believe @kringle77 designed it.

    From there, eminence has a legend driver that should do great in a small sealed box, ditto with their bassline 2012. Celestion drivers might also do well, but maybe stick to their bass guitar line.
     
  3. Rick James

    Rick James Inactive

    Feb 24, 2007
    New Jersey
    Search Hoffman's Iron Law. If you go with a very small cab you will give up low end. That's non-negotiable, no matter what driver you use. To see what really can be done download WinISD 0.7, learn how to use it. You'll find out, for instance, that a Beta 12 in 1 cu ft sealed has an F3 of 87 Hz, is 10dB down at 60 Hz, and is displacement limited to 115 watts below 100 Hz. That means you can't use EQ to bump up the low end, since 10 dB of boost at 60 Hz increases the power output by a factor of ten. Even if the amp has that much power the driver wouldn't be able to handle it, either mechanically or thermally.
     
    Pbassmanca likes this.
  4. voided3

    voided3

    Nov 11, 2008
    Thank you! The BassLite S2012 does also seem to fare well in a small sealed cabinet and looks like it could handle about 125 watts in that application. Celestion does have the BN12-300S, though it's not clear to me whether it would work well in a sealed cabinet or not.

    Thank you for the data! I suppose I should give the context that my idea for the cabinet is something very light to use with my Rumble 500 head in a drummer-less jazz setting or to use to playing solo with a Bass VI so high SPLs at 60 Hz are not mandatory. I presume the BassLite S2012 would fare about the same as the Beta 12A-2 in the same cabinet?
     
  5. AstroSonic

    AstroSonic Supporting Member

    Dec 10, 2009
    rural New Mexico
    IF you want a sealed, 1 cf cab with a 12 inch, the Beta and Basslite are good candidates. They both produce a very similar bass response profile, even to an F3 of 92 Hz. The slow rolloff (12 db/octave) allows an F10 of about 54 Hz. Many bass players would consider that to be fine for a guitar cab. Either of them would handle a light bass boost to add some low end. You're not talking loud or a large venue so they should be fine. However, considering Hoffmans Iron Law, check out this alternative. The B&C 8BG51 (8 inch) in the same 1 cf box, but ported (Fb= 48 Hz): F3 42 Hz, F10=38 Hz. Excursion limited to 140w down to 37 Hz. You get real bass cab performance, but you trade sensitivity (5-6 db) relative to the Beta and Basslite. Since the application only requires low to medium volumes and 100w power handling, this would seem to be an acceptable alternative. All 3 drivers have an upper mid/lower treble presence rise, and are decent full range candidates. Both 12's are excursion limited below 73 Hz at 140w.
     
    Last edited: Apr 25, 2018
    Oatis and voided3 like this.
  6. voided3

    voided3

    Nov 11, 2008
    I suppose this is where I have a confession to make: I already own the cabinet in question, a Yamaha THRC112 1x12 sealed guitar cabinet, which limits me to the 12" form factor, but that B&C driver is a compelling option. I have lined the Yamaha with polyfill already and swapped in an Eminence Swamp Thang guitar speaker, but was considering re-purposing it for bass as I have moved on to other guitar cabinets (for gigging on guitar).

    I have tested the cab as it currently is with my Rumble 500 head for bass and it sounds surprisingly good with a little EQ, almost like a miniature Ampeg, which inspired me to do a driver swap so it would survive at volumes louder than somewhat quiet testing at home. Given the goals of this cabinet, I feel the Basslite might be the better choice due to weight.

    Now that I've spilled the beans, though, should I try the Beta or Basslite in the Yamaha cab or just invest in something like a Trace ELF 1x10" cabinet or GK MB110 combo? I'd like to avoid getting close to the Aguilar SL112/Mesa Subway 1x12 price range, as nice as they are.
     
    Pbassmanca likes this.
  7. BogeyBass

    BogeyBass Inactive

    Sep 14, 2010
    1 cubic foot for a 12" is extremly small and yes the design intent would be for very tight mid bass. And the small enclosure is for power handling. The resulting high cabinet Qtc would be filtered out with high pass filter.

    For full range bass application .8 Qtc for the 12a2 would be around 1.6 to 1.8 cubic feet almost twice as large.

    For tradeoff on power handling 1.6 is good volume and wont have to much ripple response. Going smaller will bring up a bass peak and be boomy.

    For less ripple just plain old 2 cubic feet will be fine sealed. Treadeoff is less power handling.

    A overall good design would also be a 2x12 at 3.4 cubic feet. Which gives good sensitivity. Good power handling. Good ripple response etc etc.
     
    onamission likes this.
  8. AstroSonic

    AstroSonic Supporting Member

    Dec 10, 2009
    rural New Mexico
    You could use the B&C. You would need to make an adapter plate (1/2 inch plywood sized to fit over the baffle board, with a hole for the 8 inch driver) - you might even be able to put the driver and port on the 'plate'. OTOH,if you are pleased with the result you get from the 'Swamp Thang', choosing either of the 12's is a good way forward. For your purposes, the Basslite has a little more upper mids presence and is lighter 4.1 vs 7.5 pounds).
     
    voided3 likes this.
  9. 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 Eminence BP122 is optimized for a sealed box, which makes it unusual in this day, though it can be used in a vented box. Sealed box of about 1 cubic gives an F3 of about 70 Hz. The tradeoff is lower efficiency than a vented-box woofer and less top-end extension. While the top end doesn't have as much energy as the Beta 12 or Basslite 12, its upper-mid peak is arguably in exactly the right spot for electric bass. And, if you ever decide to do an add-on midrange driver, that would be pretty easy because you could let the BP122 just roll off naturally and bring in the mid to fill in the top couple of octaves.
     
  10. voided3

    voided3

    Nov 11, 2008
    Hmm, another contender, I see. The lower efficiency is concerning given the similar power handling to the other drivers, but as I intend to use it with a head that does 350 watts at 8 ohms, I would imagine that I would be ok. I like the deeper frequency response spec of the BP122 but a 4 dB efficiency drop would be noticeable.
     
  11. 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)
    Yeah, tradeoffs.

    Okay one of the modelling programs I have is the one Eminence sells, so it has pretty accurate information (including curves) for their drivers. Comparing the BP122 with the Basslite 2012, both in a sealed box, both getting the same amount of power, this is what I see:

    Below 130 Hz, the BP122 is actually louder. From 130 Hz to 300 Hz, the Basslite is a little bit louder. North of 300 Hz, with the exception of the 1.5 kHz region where the BP122 has its upper-mid peak, the Basslite is a lot louder.

    If we factor in the higher power handling of the BP122 (300 watts vs 150 watts), now the BP122 will go significantly louder from about 400 Hz on down, their average is pretty similar from 400 Hz to 2 kHz, and then the Basslite is louder north of 2 kHz.

    The Beta 12A2 is a little bit louder than the Basslite up to 2 kHz, and then north of 2 kHz the Basslite is louder.

    So in practice I don't think it's the lower efficiency per se that differentiates the BP122 from the Basslite and Beta 12, but rather the tonal balance: The BP122 has the most bottom end, the Beta 12 has the most across the midrange region, and the Basslite has the most top end, but the differences between the latter two are not all that great.
     
  12. voided3

    voided3

    Nov 11, 2008
    Well, with that extremely detailed and much appreciated reply, I've decided to give the BP122 a shot. I'll report back once I receive the speaker!
     
  13. 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)
    Sounds good! Please post your impressions... if the BP122 proves to be a good "convert a 112 close-back guitar cab into a 112 bass cab" woofer, that could be valuable information for a lot of people.
     
  14. BogeyBass

    BogeyBass Inactive

    Sep 14, 2010
    Its muddy driver
     
  15. 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)
    Is that a new woofer? I don't remember seeing it before. Looks VERY nice!!
     
  16. micguy

    micguy

    May 17, 2011
    A 1 cubic foot box for a single 12 is pushing things pretty far - that's smaller than most 112 cabinets you'll find on the market, and even those are compromised in terms of performance - very few bass guitar cabinets you can buy reproduce a low E at anywhere near the same gain as higher notes. With an F3 of 93 Hz, that's (my opinion) an OK guitar cabinet. For bass, you won't get what I'd consider a good combination of low frequency extension and efficiency in that size. You might like it, but it won't exactly boom.
     
  17. voided3

    voided3

    Nov 11, 2008
    The Eminence plans for a “small sealed box” for the BP122 I decided to purchase give an F3 of 70 Hz. The dimensions of the Yamaha cabinet I will install it in are slightly larger than the Eminence box so think it will be good for the lower volume situations I intend to deploy it in. I realize I’ll be losing some efficiency compared to the Basslite or Beta, but with 350 watts available it should be able to deliver what the driver is capable of delivering. Worst case scenario, it’ll be a good sounding practice amp to keep under my desk!
     
  18. DiMarco

    DiMarco Guest

    Feb 4, 2010
    That model has been around for a couple of years. Because of its extended range up to 5k you can have a hf unit crossover from there, meaning it can be pushed harder then utilizing it from, say, 3.5k. It also means a cab with no hf unit added will probably sound very full range. Xmax of the woofer is also good... These aren't exactly cheap units however. But yeah. Monstrous specs!
     
    DukeLeJeune likes this.
  19. alaskaleftybass

    alaskaleftybass Will Hanbury, Jr. Supporting Member

    Mar 21, 2012
    Sitka, Alaska
    I'm intrigued by your idea. If you don't mind, a few questions. Is this an experiment, do you need the cabinet that small for some reason? What kind of amp are you using with it? Do you plan on using it in a band situation? I'd imagine, if you were to play live, you'd probably want two cabs instead of one.
     
  20. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    Feb 26, 2021

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