Piccolo8, cab build for piccolo bass

Discussion in 'Amps [BG]' started by Arjank, Aug 26, 2013.


  1. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Time for a new cab build :cool:
    After the 210 with coaxial mid/high driver it's time for something totally different(and less complex).
    It's going to be a cab for my piccolo-bass, it should also be good enough as rehearsal/small-gig amp for regular 4-string basses.
    Concept should be simple, 1 driver, small, cheap and enough power for rehearsals and small jazz/blues/pop gigs.
    Since it's also a cab for piccolo bass it should not have a tweeter, cranking the mids could blow it up.....
    Because it's a tweeterless concept I need a driver that's not to big(better dispersion) and still can handle some power --> 8" driver.

    Options:
    -Faital pro 8 pr 200
    -Beyma 8G40
    -Beyma LW30
    -Ciare 8.50ndw
    -Ciare NDC8-3
    -Oberton 8MB201

    The faital is to expensive and it's already used in the Crazy8 &88 (don't wanna be a copy-cat :) )
    The Ciare's are also to expensive.
    The Beyma 8G40 is a great driver but it's also more expensive then the Oberton which has almost the same technical specs.
    For those who want to build the Piccolo8 and can't buy the Oberton then the Beyma 8G40 is the perfect replacement driver (it has slightly more top end but the Oberton probably has better dispersion so they won't sound very different)

    Conclusion, it's going to be the Oberton 8MB201 which costs a fraction of the Faital but will perform almost the same (the Faital can be tuned lower though but that's not necessary for 4-string).

    The cabinet will be horn-reflex, that's a ported cabinet but the port's mouth will be approx. 1.5 times the cone area. When optimally tuned it will perform slightly better then a regular ported cab. :)

    Here are some pics of the driver, I just picked it up at the importer.
     

    Attached Files:

    oerk likes this.
  2. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    I couldn't resist to connect the 8" driver to the amp just to hear how it sounds without any cabinet.
    Very nice mids, enough sparkle for slap 'n pop but never sharp sounding.
    Xmax looks what the manufacturer states, 5.75mm. Even without a cabinet hefty excursions don't bother this driver much.
    Of course you can overpower it but for an 8" driver it's very good.

    Very promising, hope to show the design of the cabinet soon.
    What I can tell is that the baffle is tilted backwards so you can just place the cab on the ground(for maximum coupling) and still receive enough mids 'n highs.
     
  3. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Here is a drawing(profile) of the cabinet.
    Hope to build this little cab soon :hyper:
     

    Attached Files:

  4. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Here's the difference between horn-reflex and a normal ported cab. The slightly higher output in the mid/bass compensates for the baffle-step. Both simulations show the 8MB201 in 11liters (the horn-reflex cab is bigger though cuz of the horn).
    The peaks and valleys of the horn-reflex don't look nice but in reality they aren't that pronounced. The simulation isn't fullspace, it's halfspace(floor).
     

    Attached Files:

  5. Register to disable this ad
  6. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Here's the simulated max spl at 200 and 400watts.
    Up to 200watts the driver is(from 60hz and up) not mechanically limit in this cab :cool:
     

    Attached Files:

  7. DD_BigBottom

    DD_BigBottom

    Joined:
    May 4, 2008
    Location:
    Los Angeles, CA
    I wouldn't stress too much over this.
    A piccolo bass is in the same frequency range as a regular guitar.
    Any bass guitar cab design with a reasonable mid-range response will work fine with the piccolo.

    BTW - what software are you using for the speaker response plots?
     
  8. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    True,
    I still think a single driver solution will work great, keeps the sound clear and the attack focussed.
    The cab should also function as a micro-cab solution for regular 4-string.

    AJhorn
     
  9. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Depends on what you're after. If you EQ it to get e.g. Stanley Clarke's solo tone (extremely cranked mids) you will blow the tweeter in most of these bass cabs when you go loud.
    That''s also one of the reason I want a single driver solution.
     
  10. will33

    will33

    Joined:
    May 22, 2006
    Location:
    austin,tx
    Disclosures:
    Use of this field for any other purpose is prohibited
    Following along here...picking up knowledge.

    I can see the large port area contributing a bit more output....does this qualify as an old school "slot port" or slot loaded driver? I always have a helluva time figuring tuning on those. I've also been told they can "drift" under varying power levels, so a small signal impedance measurement or "dancing rice" method doesn't tell the whole story.

    I don't have gear to test beyond small signal sine and rice on the cone. Can AJhorn simulate that sort of thing?
     
  11. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    It's like a slot ported or tube ported cabinet except that the port starts with approx 1/4th of the cone area and ends at approx 1.5 times the cone area. This should yield a slightly better coupling to the air. Tuning these kind of cabs can only be done by simulating them in e.g. AJhorn.
    Don't recall that the tuning of these kind of cabs will drift under varying power levels. Those horn-reflex loaded designs are especially suited for PA use.

    The version I have can't do that, and as far as I know no simulating software can do this, maybe Akabak.

    The only way to find out is to do impedance sweeps on the whole cab at different input levels, 1, 10, 100watts, etc.
     
  12. will33

    will33

    Joined:
    May 22, 2006
    Location:
    austin,tx
    Disclosures:
    Use of this field for any other purpose is prohibited
    Cool, thanks.

    I can run the tone to a poweramp but don't have program to do the impedance in a single sweep. Can do the measure across resistor/measure across coil trick but that's very tedious....and loud. :)
     
  13. DD_BigBottom

    DD_BigBottom

    Joined:
    May 4, 2008
    Location:
    Los Angeles, CA
    Thanks for that. I haven't seen it before and will check it out.
    I've been looking at SoundEasy but is a bit pricey and I'm more interested in modeling than measuring.

    I'm looking for a small box solution for bass guitar in small club type venues and look forward to see how your project turns out.
     
  14. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Cool.
    If you want to build it, the Beyma 8G40 will work in that cabinet too and perform approx. the same :)
    If you really want to use the 8MB210 then there's allways a way to get/ship it to you.
     
  15. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Yeah, plywood panels are ready.
    Lets build this cute cab! :bassist:
     
  16. DukeLeJeune

    DukeLeJeune Only immortal for a limited time Gold Supporting Member

    Joined:
    Nov 24, 2008
    Location:
    Preston, Idaho
    Disclosures:
    Owner & designer, AudioKinesis; Auth. mfg, Big E (Home Audio only)
    Very interesting design!

    I tried something similar years ago, but without the benefit of a modelling program, and the bottom end was disappointing. The "mouth" of my horn was about 1/2 the cone area as I recall, and that may have been the problem. I wasn't taking into account that it's not only a horn but also a port.

    I presume you've worked with AJHorn before and found its modelling to do a good job of preducting measured response down low, say south of 100 Hz?
     
  17. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Thnx for chimin' in Duke, the port area, throat area and lenght are all important. Actually it's still a ported design but when executed well it should have better coupling to the surrounding air, this is where the greater mouth area comes in.

    AJhorn does a great job, it is also used extensively by a German DIY loudspeaker magazine that has showed several times how well the simulations agree with the measurements.

    I only would like to have the latest version of that program cuz it's more flexible then mine.
     
  18. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    Almost done :bassist:
     

    Attached Files:

  19. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    Joined:
    May 6, 2000
    Location:
    Groom Lake, NV
    Disclosures:
    Independent Contractor to Bass San Diego
    Are you going to put some kind of cone protection on it? I notice there's no recess around the front.
     
  20. Arjank

    Arjank

    Joined:
    Oct 9, 2007
    Location:
    Above Amsterdam
    There's going to be some sort of grill, but that's for later concern.
     
  21. BassmanPaul

    BassmanPaul Gold Supporting Member

    Joined:
    Aug 25, 2007
    Location:
    Toronto Ontario Canada
    I too have a question if the OP will forgive an old fart's thirst for knowledge. If a Piccolo bass is tuned to the same frequencies as the lower four strings of a regular guitar, what is its use???
     

Share This Page