My home made sub

Discussion in 'Home Theater Projects' started by Daniel_AVR, Mar 4, 2004.

  1. Daniel_AVR

    Daniel_AVR Extra

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    The project is now finished...

    I build my first DIY project... as many, the easiest first project to build is a sub...

    I was a long shot, I had to educate myself a bit before doing anything, with the help of some other fellow sound lovers here... that I want to thanks...

    The driver picked is a 12" Titanic MKIII (for his specs., his rubber surround, the great reputation of parts express)... in a ported 3.4 ft^3 box made of 1" MDF (3.8 rough, before driver, brace, amp)tuned to a bit less that 21hz.... 20.8 Hz in fact... just to respect the rule of 1 x dia. of the port distance between the end of the port and the opposing inside wall.

    The amp used is an Hypex HS 500 bought on an ebay auction that I can't resist.... you know this feeling... "I want it...I want it..!!"

    I've put an input cup to be used later as an output cup to add another passive box to the unit.

    The result is tremendous.... clearly much better than the Velodyne CHT10 I had on test last fall. After a few tests I add 1" thick of polyester on all box walls, it help to warm the overall sounding.... I also use a plug to plug the port, and it make the use for music much better ... to my taste

    As my room is pretty large (17' x 20') and had one completely open side, I'll probably made another one later, but a sealed one, this one would be locate at the other end of the room to evenly fill the room. The setup is already able to fill the room, but to rattle the walls, the driver is too much near his limits to use it that way on long periods.

    For those who like to see it, (as I like myself to see others projects) I put some pictures on this link: (just copy the link to your browser)(updated link, thank to Dave)

    //community.webshots.com/album/123013201KaNAzy

    any comments welcome

    I now feel part of the DIY community for real... hehe

    Dan
     
  2. ColinM

    ColinM Cinematographer

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    Link asks for login...Sounds like a nice sub, though!
     
  3. Dave Poehlman

    Dave Poehlman Producer

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    Ha! I found Dan's Pics! [​IMG]

    Nice looking sub!

    What is that finish on there?
     
  4. Bob K

    Bob K Stunt Coordinator

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    Dan,

    Congratulations -- beautiful job! You should have a great sense of accomplishment, and on top of that you now have a great piece of equipment. Warning: speakerbuilding is addictive. It sounds like you already know what your next project is!

    Tempest Construction Pix: http://www.audiocircle.com/circles/m...view_album.php
     
  5. BlakeN

    BlakeN Stunt Coordinator

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    Nicely done. I hope my current project turns out even close to as good as that> [​IMG]
     
  6. Ben L C

    Ben L C Agent

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    Great Job Dan. I am sure you will have fun with it. Looks great.
     
  7. Wayne Ernst

    Wayne Ernst Cinematographer

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    Daniel,

    Great job on the sub. It kind of sucks that the driver had a bit of an issue. However, once the replacement driver gets installed, you'll be able to get "rockin and rollin." [​IMG]
     
  8. Daniel_AVR

    Daniel_AVR Extra

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    Dave,

    I use Krylon "make it stone" textured paint spray can finish..... so easy to use that even a child couldn't fail.

    The texture even help masking slight defects.... so the finishing steps where all on the same day... no need for body-shop level finishing.....
     
  9. Justin Ward

    Justin Ward Supporting Actor

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    Thats the same tpye of finish I used on my stands and flexy rack. I used a granite colour though. The finish is quite impressive and very durable.
     
  10. KyleGS

    KyleGS Second Unit

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    Daniel- Great looking sub!
    If you don't mind me asking-- is that a 3 or 4in flared port?
    What color stone paint is that? I use the Duplicolor bedliner and that looks very similiar.

    How do you compare the sealed and ported when doing critical stereo (music) listening?

    I'm about to start a similar project with the MKII driver but it will have three way versatility.

    I plan on 3.8cf net, two 3" flared ports with two plugs. Both ports open =24.5hz, one port open =~18hz and two plugged = low Q sealed for critical listening.

    It's going to be an end table with a thick ceramic tile top.

    I would use the 25hz tuning for parties and when friends come watch movies. I would go 18hz for "my" movie listening and sealed for music.
     
  11. Daniel_AVR

    Daniel_AVR Extra

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    Kyle,

    You're welcome, I'm more than happy to share experience, as I learned myself huge amount of infos from others projects here.

    I used a 4" flare port from precision port, less than 4" give too high air velocity in the port when modeling.

    When blocking the port, sound is much more natural on music listening, the ported xtra bass extension is cool on cinema but unreal with room gain for music. But take in consideration that you'll have a low Q sealed configuration when port is close... it's superb on classical and smooth listening but it lacks a bit on chest pounding rock bass. Don't get me wrong, it still pounds and shake the floor, but it didn't pound on right freq's for rock, IMHO it hit a bit too low for rock.

    quote;
    "I plan on 3.8cf net, two 3" flared ports with two plugs. Both ports open =24.5hz, one port open =~18hz and two plugged = low Q sealed for critical listening."

    This could be the best of all worlds, a cool idea.... in fact I'm a bit jealous of....[​IMG]...it's worth the try, you'll get a slight peak of around 1.25 db in the range of 35hz with 2 ports... but it's right in freq's to rock... those flared ends take some place, need some delicate planning to put them in. But you should be ok.

    I've been warned about nothing less than 4" port for 12" drivers, but here it turns out that I really think that flared 3" could do the job, even if WinIsd model airspeed exceeding 65 ft/s

    Let me know, I'm interested to follow your project...
     
  12. KyleGS

    KyleGS Second Unit

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    Here's my reasoning for dual 3in ports: I imagined that when I want high volumes where airspeed would be a problem I probably wouldn't be doing any critical listening at this level anyway- hence 25hz tuning. I rarely jam out but when I do its usually on Friday afternoon to some 70s and 80s rock in which I would probably want both ports open for punch OR when my friends come watch LOTR or Matrix and want to "see what see'll do."

    Otherwise- I am very conservative with the volume knob and like my jazz, blues, etc at moderate to low levels in which one port would be just fine or for absoulte audiophile bass- seal it up. Also-I watch movies relatively low.

    Back to your box-- [​IMG] - the reason I asked about the 4in port was with WinISD Pro I come up with a 20in port for 3.4cf @ 20.8 hz. I was under the impression that the precision ports could only make up to a 17in port with the supplied center length tube. Do you have stuffing, acous. foam, etc?

    Lastly - what color was the stone paint you used?
    Thanks again

    Kyle
     
  13. Daniel_AVR

    Daniel_AVR Extra

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    Kyle,

    Your right about air velocity, you'll hit high velocity only near max output on low feq's, otherwise it's ok.

    I first tried the sub without any stuffing, and tried it with 1" thick polyester on the inside walls... and it's better that way.. to my taste.. warmer

    I didn't use the supplied center tube, I used a 18" white pcv tubing (it ended up 21" with flares), that I had to grind a bit on the O.D. to match the fittings.., and paint it black. It have the same I.D.

    The paint is "odsidian" color if I'm right..., it's black with some white particles in it.

    DAn
     

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