maelstrom/1803 in sonotube?

Discussion in 'Archived Threads 2001-2004' started by Brad Dixon, Jan 10, 2002.

  1. Brad Dixon

    Brad Dixon Stunt Coordinator

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    I've read this forum for awhile now and had planned on building a tempest sonotube based on some of the designs here. With the maelstrom and 1803 available for use I was considering using one of those in aprox 14cuft.

    Problems/questions

    1. I have the spousal ok for a tube not a traditional box. Can a tube work or would it simply be to light and vibrate around the room?

    2. I was thinking of trying the 10" port(not sure who's design this was, i apologize) with a 30" tube. This would have 2 3/4" mdf endcap inside the tube with a third on top which would actually hang over the edge an inch. I was planning on then using standoffs to put a raised cover/encap 3-4" above the end of the tube.

    For the bottom of the tube i was thinking of the same except using 3circles inside tube with overhanging endcap and then the standoffs then 2circles for base.

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    The reason i thought 30" might be better as it would cause more mdf to be used therefore making tube heavier.

    3.Port length, would there be a problem with putting a bend in the port? 10" port makes the port to long for tube(atleast from what little i've played with adires lspcad)

    4. amp should be a problem as i also got wife ok to purchase one but must keep it under $500. Looked around and there a a few that appear to be capable.

    5. eq and impedance probs. I've seen some post talking about this but kinda lost here. If in building the tube using one of these drivers will require more electronics or eq then it probably out of the question as i don't have ok for that.

    I realise I could simply do a tempest but since i have the ok for a large tube I thought may aswell well build the baddest beast I can. Guess I'm lucky my wife actually like the lok of the tubes and my father has been working with wood for years and has offered to help build so i have access to any tools i'd need. Honestly he'll probably do most of the work cutting/finishing and i'll be assembling.

    Hope such a long post for first post doesn't bother anyone.

    Thanks for any input,

    Brad
     
  2. Patrick Sun

    Patrick Sun Moderator
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    1. Make sure you will be able to fit a 30" tube through the doorway or entryway of the room the sub will reside in. [​IMG]
    2. If your port length is too long, perhaps it'll work if you use a 24" wide sonotube (requiring a tall tube).
    3. Consider an 8" wide port, and calculate its length if you really want to use the 30" wide tube.
    4. The need for EQ is more dependent on the driver you use, rather than the form of the enclosure.
    5. The weight of the sonotube sub can be increased with added layers of endcaps. You should be okay with 3 layers of 3/4" wood/MDF on each end. Using a 30" tube over a 24" tube won't make that much difference in weight.
     
  3. Dustin B

    Dustin B Producer

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    There is a big difference in displacment capabilities between the BP1803 and a Maelstrom. The 1803 can displace twice as much air as the Maelstrom. As noted in other threads the BP1803 should have over 1000 watts, and will likely need an eq. So if you can handle both those, the 1803 may be the way to go.

    Adire's site talks about how the Maelstrom can give great 20hz output even in small sealed boxes. I see this as the main advantage of the Maelstrom over a Tempest. However, in a large ported enclosure I'd be more inclined to go with a dual Tempest sonosub over a Maelstrom. Twin Tempest have a 5L displacement capability while a single Maelstrom has 3L. Plus twin Tempest cost less than a Maelstrom :p)

    I've been playing recently thinking about my next sub (if it ever happens). I was thinking 440L tuned to 16hz with twin 6" ports and twin Tempest driven by a QSC RMX 850. I'd use 24" or 26" sonotube and put a driver and a port on each endcap. On the top endcap I'd recess the driver and get one of those 15" perforated metal grills for appearance and to protect the driver. I'd also use a 6.5" or 8" perforated metal grille to protect the port and for appearance. I haven't worked out the dimensions completely yet to know if I could fit the two grilles on an endcap.

    Just another idea.
     
  4. Mike Strassburg

    Mike Strassburg Second Unit

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    Dustin,

    I'm building pretty much exactly the sub you are considering.

    Straight from Dan W: "For serious output, I'd look at a 24" diameter tube, 72" long. Mount one Tempest and one vent in each end. For the vents, use 6" ID by 20"L pipe. Double-thick the endcaps (1.5" thick, assuming 3/4" thick stock) from void-free plywood (Baltic birch or marine grade plywood). Should end up with a net 480L, tuned to 17 Hz. Use some 4" high legs on the bottom to space the sub off the floor. The sound should be dominating and effortless, with clean extension down to 15 Hz or so in-room. And SPL levels should be well above reference, in the 120 dB SPL range from 15 Hz and up"

    I've bought the Sonotube and PVC already, and will probably end up using MDF since HD stocks it. Borrowed a good router from a friend. Just waiting for the Tempests to ship, should be end of January according to Adire.

    Take care...Mike
     
  5. Brad Dixon

    Brad Dixon Stunt Coordinator

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    After more reading(same posts as before but looking for different info) I'll plan on going with the dual tempest. Now a couple questions.

    1. Since adire says 340l for single(for ebs alignment), should i try to double that for dual? I've found just a couple posts mentioning tubes that size. Other than size is there something i'm missing?

    2. Tuning frequency? 14-16hz? This would be 2 8" ports 27.75"(16hz) or 40.5"(14hz). Was planning on 30" diameter tube to keep shorter(I realise 24" would be less wastefull).

    I'm not trying to build a massive tube but since I have the ok I'd rather build it right or as close to it as I can first time. Never know when I'll have the ok to do it again. If the difference bewteen 680l and 480l are minimal or not noticable unless specifically trying to notice any difference I'll build a smaller tube.

    Spl is not a real concern, moving the house from it's foundation is. At the moment we have a Paradigm PS1000. It leaves a little to be desired compaired to the local movie theater.

    Thanks and any thoughts are appreciated,

    Brad
     
  6. Jack Gilvey

    Jack Gilvey Producer

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  7. Mike.D.K

    Mike.D.K Stunt Coordinator

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    I just completed a 1803 sonotube. I had two tempest sonotubes and had the time and itch to build more.So I sold the tempests to my nephew and built the 1803. The tempest seem to give a little more bottom but the one 1803 has more output than both the tempest. The 1803 does not bottom as easy as the tempest although the tempest only bottomed at extreme volumes. I used three endcaps top and bottom and a 30inch baseplate. All made from 3/4 MDF. The sub does not move, it is very stable. Boy it is heavy though!!
     

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