Announcement

Collapse
No announcement yet.

bandpass for midbass?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • bandpass for midbass?

    I was thinking of building a prototype 3 way PA top that would have passive crossover. (Maybe even satellite for home use).
    To save on some of the pricey crossover components the thought came to mind that a bandpass box could be used from 80Hz or 100Hz to about 200Hz or so.
    The delta 10a comes to mind.

    The advantage would be very small box (for this portion of speaker at least)
    Driver hidden, no protective grill needed over this speaker.
    Just a simple coil to cross over at around 200Hz or so to midrange unit(s) if that is even needed.
    Box could be built in a way that the height could be made under 10" high which is what I'm after, (but it would then have to be 10" deep and wide, but that's no problem of course).

    The questions then are, has anyone done this, and would a bandpass sound good out to 230Hz? Would want this sounding really good!

    Thanks in advance.
    Two very good sociological markers.
    The state of our public wash rooms.
    How we treat each other behind the safety of a monitor and key board.

  • #2
    Re: bandpass for midbass?

    Originally posted by Music is life View Post
    I was thinking of building a prototype 3 way PA top that would have passive crossover. (Maybe even satellite for home use).
    To save on some of the pricey crossover components the thought came to mind that a bandpass box could be used from 80Hz or 100Hz to about 200Hz or so.
    .
    IMO there's no point in running any driver over that small a bandwidth when going from 80 to at least 1kHz isn't the least bit difficult.
    www.billfitzmaurice.com
    www.billfitzmaurice.info/forum

    Comment


    • #3
      Re: bandpass for midbass?

      There's already a precedent for a bandpass midbass device in pro sound, though the only place where the time-domain performance of a bandpass system would be tolerated in the midbass is in the professional realm. The RCF TTL33-A uses a pair of 8" midbass drivers in a bandpass enclosure for covering the range from 60 Hz to 400 Hz. (Look at the line drawing on the last page of the linked PDF.)

      http://www.rcf.it/en_US/c/document_l...=DLFE-4018.pdf

      The Italian maker Outline also does this in several of their models. (The LF section of the Outline Butterfly array is a bandpass design.)

      http://www.outlinearray.com/images/s...83_hi-pack.pdf

      Oh, and lest I forget, there's the Bose Acoustimass module.

      So it's *possible* to do, and may actually be a productive way to integrate a small, efficient midbass system into a speaker, perhaps to match a horn-loaded mid and high section.
      Best Regards,

      Rory Buszka

      Taterworks Audio

      "The work of the individual still remains the spark which moves mankind ahead, even more than teamwork." - Igor I. Sikorsky

      If it works, but you don't know why it works, then you haven't done any engineering.

      Comment


      • #4
        Re: bandpass for midbass?

        Originally posted by Taterworks View Post
        There's already a precedent for a bandpass midbass device in pro sound,
        There are many, most of them being horns, which are bandpass devices. The main reason why you don't see many 4th order and 6th order bandpass midbasses is that they don't offer much, if any, improvement over similarly sized direct radiators in either sensitivity or extension. The only real advantage they offer is their higher roll-off slope above the pass band, which can be useful in minimizing bandwidth overlap, especially when passively crossed.
        www.billfitzmaurice.com
        www.billfitzmaurice.info/forum

        Comment


        • #5
          Re: bandpass for midbass?

          A BP mid bass was considered (and prototyped) on the Harmony Central Line array project a few years back. If I recall is worked very well.

          Have you modeled the Delta 10? Some drivers may not offer much bp gain over a simple front loaded as Bill F suggest. Also, you might be able to get a little low mid bump with a smaller vented box.

          Comment


          • #6
            Re: bandpass for midbass?

            Originally posted by DSM View Post
            Have you modeled the Delta 10? Some drivers may not offer much bp gain over a simple front loaded as Bill F suggest. Also, you might be able to get a little low mid bump with a smaller vented box.
            I've modeled the Delta 10 in horns - and you don't get a whole lot of bandwidth there, either. I'd expect low bandpass gain, if any.

            As a direct radiator, in small vented boxes, you don't get a big low mid bump. Just fairly flat down to 100 Hz in half space. Perfect for floor wedges, but a little thin in the midbass up on sticks.

            Comment

            Working...
            X