Sono tubing vs PVC

Discussion in 'Archived Threads 2001-2004' started by TedO, Mar 6, 2002.

  1. TedO

    TedO Stunt Coordinator

    Joined:
    Dec 17, 2001
    Messages:
    143
    Likes Received:
    0
    I see everyone uses sonotubing for thier sub tubes. Has anyone tried PVC?

    It comes in about the right size, I believe it would be more ridged, and doesn't have the seams sono has. I thought the smooth exterior would give me more finishing options.

    TedO
     
  2. Brandon B

    Brandon B Second Unit

    Joined:
    Mar 23, 2001
    Messages:
    263
    Likes Received:
    0
    A side note I usualy reply with when I see this question. PVC gives off very poisonous fumes when burned, so if you have s ub made of it and have a house fire, it's a bad thing.

    So would your record collection though

    That said, I have a temporary wofer enclosure right now built out of a 13" PVC tube. Works pretty well, but it's pretty resonant. it is thinner wall though, about .25".

    BB
     
  3. TedO

    TedO Stunt Coordinator

    Joined:
    Dec 17, 2001
    Messages:
    143
    Likes Received:
    0
    Since all the waste water plumbing in my house is PVC I don't think a sub made from it would make much of a difference in a fire.

    More of a concern is the "resonance" it produces. The wall thickness of 1/4" seams like it should be good and strong, I wouldn't go any thicker than that. Does the Sonotube have any resonace problems?

    TedO
     
  4. Brandon B

    Brandon B Second Unit

    Joined:
    Mar 23, 2001
    Messages:
    263
    Likes Received:
    0
    If you are still in your house by the time a fire has burned into your walls and gotten to your plumbing, you already aren't doing well. A large PVC object sitting out in the room is a little different matter. I only bring it up as we are forbidden to use a lot of PVC in my work (building equipment for theme park rides) for this very reason. Plumbing is generally exempt as it is in walls.

    On the resonance of the PVC tube I have, it is pretty bad if you put your hand on it, but it does not seem to radiate as sound to the same degree. Since a circular cross section is resistant to flexing unless it is an elastic material, it may be the vibration I am feeling is caused more by the endcaps transmitting energy along the length of the tube.

    I was using this piece as a sealed sub with a pair of magneplanars (it has a Lambda Acoustics 10" in it) and it was VERY clean and tight.

    Aside from the ease of applying a finish, though, I would suspect sontoube is better in every other way except durability.

    BB
     
  5. Chad Kuypers

    Chad Kuypers Stunt Coordinator

    Joined:
    May 8, 2000
    Messages:
    79
    Likes Received:
    0
    TedO,
    If you haven't checked it out yet, you may find that price and weight are deterring factors in aquiring PVC of this size. You can buy it in much thicker varieties than 1/4". You typically can only buy it in 10 and 20 foot lengths. It is MUCH more expensive than Sonotube. It also weighs a lot more in comparison. I remember inquiring at a commercial plumbing supply store about 18 and 20 inch diameter PVC. The smallest length that they would give me was ten feet. Even the cheapest version was several hundred dollars and weighed several hundred pounds.
    There could possibly be cheaper and lighter versions that I am not aware of. It really seems like it would be perfect for tube subwoofers. I just didn't want to drive down to pick up a 350 pound, ten foot long tube. [​IMG] I never ended up trying it out...
    Chad
     
  6. Brandon B

    Brandon B Second Unit

    Joined:
    Mar 23, 2001
    Messages:
    263
    Likes Received:
    0
    There are different varieties. The thin (1/4") wall stuff I used is large DWV (drain) piping (12" nominal, 13.2" or so actual inside diameter).

    Plumbing pipe of the sizes your are talking about will be closer to 1/2" wall, and as you say is VERY heavy (tens of pounds per foot).

    You can probably get short lengths of it for free if you hunt around though. Try some major contruction sites where they are redoing city piping runs and such. They consider 3 and 4 foot pieces of this stuff to be "scrap". Also, try your local plumbing supply places, like Ryan Herco, they might have a remnant they might let go cheaper.

    If this is something you're super hot to do, and want to pay shipping, I might be able to lay my hands on a 20" diameter piece too.

    BB
     
  7. TedO

    TedO Stunt Coordinator

    Joined:
    Dec 17, 2001
    Messages:
    143
    Likes Received:
    0
    Thanks for all the help. Sounds like there are too many negitives in using PVC instead of Sonotube.

    I did see some people use threaded rods to clamp or sandwich thiers subs. Is this needed or recomended?

    I plan on using 2 layers of solid core plywood (left over from another project) epoxied together for the top and bottom cap. These will be stepped to fit into the tube and I will attach a floor plate with three risers. This sub will look pretty much like my SVS.

    TedO
     

Share This Page