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DIY Cylindrical Enclosures

Discussion in 'Speakers & Subwoofers' started by Badies, Jul 11, 2017.

  1. Badies

    Badies Extra

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    Sorry for the long post...

    So I was contemplating building a pair of floor-standing speakers and I looked at quite a few different designs. I considered going with the classic sealed, square box, but it seems that lately there's been a general movement towards ovular shaped towers in high-end speakers. I realize that this helps counteract standing waves and looks aesthetically pleasing. However, from a DIY standpoint, it may prove difficult to build such an enclosure.

    What I was thinking instead was to use a hole saw and make a stack of MDF to create a sealed cylindrical design. If it would make sense I could also make any portion of the cylinder larger by cutting a larger hole in that cross-section. I am new to building speaker enclosures so I don't know if this design is worth pursuing, however I would assume because it is sealed (unless it would make sense to port) I need only worry about the volume inside (much like a traditional box design) when choosing drivers. I did some research and I came across a similar design by Jim Rogers back in the 1970's (attached ) but I don't know how relevant that would be.

    Are there any drawbacks to this design? Should I worry about any particular details not involved with traditional box speakers?

    Thanks for any feedback.
     

    Attached Files:

  2. Dave Upton

    Dave Upton Audiophile
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    I generally think that the best speakers are still variations on boxes, which are much easier to build. I would not bother.

    That said, give some of these ideas a look, there are designs and BOMs for some amazing designs at this site:

    http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm
     
  3. Badies

    Badies Extra

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    I've actually checked those designs out before. Certainly very inspirational. I guess my question was a bit vague. I really just want to know if there are any drawbacks to a cylindrical enclosure. In terms of building, It would not be very difficult (in some ways much easier) to use the stacking method like this...

    images.

    (except the interior would be a simple circle or overlapping circles for more volume [like a venn diagram cut]).

    So when dealing with a sealed enclosure, volume is obviously important, but does the shape, beyond building a rectangular box where standing waves can form, actually matter? Is there any reason for concern with a tubular cutout assuming the volume is correct?
     
  4. Dave Upton

    Dave Upton Audiophile
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    Tubular speakers can be problematic, especially when you think about how to mount drivers on a surface that isn't flat - manufacturing them is very difficult, hence why there are almost none on the market. I don't mean to be rude when I say this - but I think you should seriously consider dropping this idea. If you're going to put in the effort to build something, you should use a proven design instead of trying to reinvent the wheel (or cabinet in this case).

    Sonically, you may get some slight benefit from the dispersion of standing waves, but this is offset by complexity in building the driver baffle, which has to be flat anyway. You can buy pre-fab cabinets or flat pack kits from several sites that will likely sound better due to more choice of drivers.

    If you aren't terribly concerned about size, going with a larger cabinet allows larger transducers, higher efficiency and better low frequency response.

    Kits to look into:

    http://gr-research.com/diykits.aspx
    https://www.madisoundspeakerstore.com/speaker-kits/
    http://www.jantzen-audio.com/complete-kits-for-diy-speaker-projects/
     
  5. Badies

    Badies Extra

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    I may go that route as it seems more advisable. That being said, my curiosity still drives me to know more from a theory standpoint. What I proposed to build was not as complex as it sounds. Here's a rough cross section sketch. (the red would be the driver and dimensions are meaningless)

    Untitled.

    I wouldn't place the driver on a tangential surface as that would indeed be very difficult. but forming these cross sections would be quite easy as it's just a simple hole cut and the final product would yield a box on the outer appearance.
     
  6. Dave Upton

    Dave Upton Audiophile
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    Caveat: I'm not a speaker designer. I'd like to get the input of an expert on this as we're getting into really complex territory.

    The design as you are proposing it in that image would likely sound about the same as a box speaker on axis with a well designed crossover. Without ray tracing and modeling, it's very hard to estimate how the rounded cabinet would affect the sound, but instinctively I would guess you'd get some high frequency anomalies with such a broad face. The reason for this is how broad the side of the speaker is vs the baffle, so i'm not sure you'd get decent off-axis response either.
     
  7. Badies

    Badies Extra

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    Hmmmmm yes very interesting. It would be nice to get an expert opinion. You bring up some thought provoking ideas tho. I suppose on an intuitive level the speaker may be more directional. I was originally just thinking from the standpoint that the volume of air in the box acts as a spring and no matter how that volume is taken up the "spring" would have the same tension and therefore produce the same sound (aside from standing waves). It seems this is much more complex than that tho.
     
  8. Mike Frezon

    Mike Frezon Moderator
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    Interesting discussion gentlemen.

    I have nothing to add...except THIS LINK to a number of threads from about 15 years ago to a series of threads here about building subwoofers out of a round material called sonotube. Our own Patrick Sun was very active in this practice.

    We used to have a VERY active DIY sub-forum going on here and Patrick was a big part of that.
     
  9. Dave Upton

    Dave Upton Audiophile
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  10. Robert_J

    Robert_J Lead Actor

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    If the original design calls for a 8" wide baffle, then make sure the new baffle is the same width. Yes, the rest of the cylinder isn't the same shape as a standard box speaker and a little baffle step diffraction might happen but you probably won't notice. The biggest part is finding a good design. Do not start from scratch on your first build.
     

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