Page 1 of 5 123 ... LastLast
Results 1 to 25 of 119
  1. #1
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641

    18” down-firing EGG shaped sub build…

    I ordered the driver, bought the wood, and will be starting the cutting this weekend. This will be a bit of an unusual build. Some will say that it will be ugly, but the wife has given her stamp of approval, and more importantly, I like it. It should be a nice step up from my current Titanic III 15”.

    The driver will be a Maelstrom-18".
    Amp will be a Behringer EP4000.
    EQ will be a Behringer DSP1124P Feedback Destroyer.
    Using ¾” MDF to make a 5.75 cubic foot sealed enclosure (internal).
    Walls to start at 2” thick and then be sanded down to maybe 1&3/4.

    I don’t have any graphics software but have managed to put something together with Excel & Word. Here is a cross section of what it should end up looking like. It will be 30” wide by 35.25” high. I have noticed that with Excel, dimensions will be skewed from one computer to the next depending on settings. The width should be 85% of the height, so if you want to see it scaled properly, you may need to do some stretching of it.

    What do you think?
    Attached Images Attached Images
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  2. #2
    Forum Regular audio amateur's Avatar
    Join Date
    Mar 2006
    Location
    France
    Posts
    2,603
    Awesome project, but why not use sonotube and make a cylindric enclosure? Would be much easier to make!



    Also, the sub's Qts suggests that it would work well (maybe better) in a ported enclosure. What program did you use to get that volume?

  3. #3
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Thanks AA,

    A cylinder would not be as unique. This will be a one of a kind work of art. (And it gives me something to do while wifey & baby are out of town)
    I checked out the graphs available from Kevin’s website. I like the in room responses for sealed. Besides, I’ve heard and built many a speaker. Sealed almost always sounds better to my ears. With 18” being driven by almost 2500 watts, it should be more than loud enough for me.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  4. #4
    Forum Regular audio amateur's Avatar
    Join Date
    Mar 2006
    Location
    France
    Posts
    2,603
    As long as you know what you're doing
    If you need any advice let me know.

  5. #5
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    I could use someone to hold my wood while I cut it.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  6. #6
    Forum Regular audio amateur's Avatar
    Join Date
    Mar 2006
    Location
    France
    Posts
    2,603
    Here are a few sub ideas just in case...

    Rubix cube sub


    The Deathstar


    A true dipole subwoofer by Elemental Designs


    And finally the monster RE XXX subwoofer driver
    XXX2009-1.jpg
    Last edited by audio amateur; 04-30-2010 at 01:29 AM.

  7. #7
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    I like the rubics cube.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  8. #8
    Super Moderator Site Moderator JohnMichael's Avatar
    Join Date
    Apr 2005
    Location
    Central Ohio
    Posts
    6,218
    GM maybe I have been around the medical field too long but it looks like a suppository.
    JohnMichael

    Vinyl Rega Planar 2, Incognito rewire, Deepgroove subplatter, ceramic bearing, Michell Technoweight, Rega 24V motor, TTPSU, Ringmat Anniversary mat, Michael Lim top and bottom braces, 2 Rega feet and one RDC cone, Benz MC Gold, GSP Fanfare 3 w/PSU1

    Digital Sony SCD-XA5400ES SACD/cd, Marantz SA 8001

    Int. Amp Krell S-300i

    Speakers Focal 806V/Focal 800 stands

    Cables AQ Rocket 33's, Diamondback XLR's & IC's

  9. #9
    Vinyl Fundamentalist Forums Moderator poppachubby's Avatar
    Join Date
    Aug 2009
    Location
    Analog Synagogue
    Posts
    4,396
    The Rubix Cube is awesome, and they even solved it!

  10. #10
    Loving This kexodusc's Avatar
    Join Date
    Nov 2003
    Location
    Department of Heuristics and Research on Material Applications
    Posts
    9,047
    GM...that looks AWESOME!

    You probably know this already...but especially for an 18" woofer. BRACE that cabinet.
    Easiest is probably just shelf braces running across at 2 layers with big holes in them...don't make it symmetrical and you'll help break up internal resonances a bit too...

    What are you using for damping material?

    And how are you connecting the layers? Glue and brad nails?
    Solid choice of amp. You are unlikely to ever come near clipping that jobber. You just using binding posts to connect it to the woofer?

    Geez, I feel puny with only two 15" subs.

  11. #11
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Quote Originally Posted by kexodusc
    GM...that looks AWESOME!

    You probably know this already...but especially for an 18" woofer. BRACE that cabinet.
    Easiest is probably just shelf braces running across at 2 layers with big holes in them...don't make it symmetrical and you'll help break up internal resonances a bit too...

    What are you using for damping material?

    And how are you connecting the layers? Glue and brad nails?
    Solid choice of amp. You are unlikely to ever come near clipping that jobber. You just using binding posts to connect it to the woofer?

    Geez, I feel puny with only two 15" subs.
    Thanks Kex. I’m glad you like the design.

    I was wondering about bracing. There are no flat walls that will be able to flex. I’m using all rings. Circles are much stronger than boxes. The walls will mostly be 2 inch thick except for a few that will be 4 inch thick. Will there still be a need for bracing? If so, I could just make one ring a solid disk and then cut a bunch of holes in it.

    I will be using 2 inch Mineral Wool. The case of 6 is way more than I’ll need but I may find other uses for it around the house. http://www.atsacoustics.com/item--Ro...f-6--1006.html

    Glue and screws. This way I will need minimal clamping for the glue to dry. Just normal yellow wood glue. Thinking of maybe 2 inch screws so each will help to hold 2 or 3 pieces together. I’ll drill and countersink first.

    The amp should be good. Bench tests show it at 2400 watts RMS .1% THD bridged to 4 ohms. I’ll run it as is for a while to see if the fan bothers me before I attempt the fan mod. I’ve read that the EP4000 is the same as the EP2500 with minor changes, including a quieter fan. We’ll see.

    Ordered these posts from PE. http://www.parts-express.com/pe/show...TOKEN=93446984
    And these T-nuts. http://www.parts-express.com/pe/psho...umber=081-1090

    Also received 10 feet of BlueJeans 10 gage wire. That should be enough for my needs.

    I believe that two 15” subs will outdue one 18” sub. No need to feel puny.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  12. #12
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Quote Originally Posted by JohnMichael
    GM maybe I have been around the medical field too long but it looks like a suppository.
    Uh yeah.... It's because you've been in the medical field too long. That's what we'll go with....




    What's my excuse?
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  13. #13
    Forum Regular audio amateur's Avatar
    Join Date
    Mar 2006
    Location
    France
    Posts
    2,603
    Kex, do sealed speaker enclosures generally need to be loosely stuffed? Does this also apply to sealed subwoofer enclosures?

  14. #14
    I took a headstart... basite's Avatar
    Join Date
    Jul 2006
    Location
    Mortsel, Antwerp, Belgium, Europe, Earth
    Posts
    3,226
    That looks like an awesome design indeed!

    I agree with Kex though, brace it, brace it real serious!

    what glue are you going to use to glue the layers to each other? whichever you use, be sure to do only 2 layers at one time, and clamp them, as good as possible, you don't want any holes in the glue...

    btw, are you leaving the walls like that? or are you planning on using a filler of some kind (or cement, which might be more appropriate ), to make it a smooth/real egg like enclosure?

    Good luck, and don't cut your fingers of
    Keep them spinning,
    Bert.
    Life is music!

    Mcintosh MA6400 Integrated
    Double Advent speakers
    Thiel CS2.3's
    *DIY Lenco L75 TT
    * SME 3012 S2
    * Rega RB-301
    *Denon DL-103 in midas body
    *Denon DL-304
    *Graham slee elevator EXP & revelation
    *Lehmann audio black cube SE
    Marantz CD5001 OSE
    MIT AVt 2 IC's
    Sonic link Black earth IC's
    Siltech MXT New york IC's
    Kimber 4VS speakercable
    Furutech powercord and plugs.

    I'm a happy 20 year old...

  15. #15
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Quote Originally Posted by basite
    That looks like an awesome design indeed!

    I agree with Kex though, brace it, brace it real serious!

    what glue are you going to use to glue the layers to each other? whichever you use, be sure to do only 2 layers at one time, and clamp them, as good as possible, you don't want any holes in the glue...

    btw, are you leaving the walls like that? or are you planning on using a filler of some kind (or cement, which might be more appropriate ), to make it a smooth/real egg like enclosure?

    Good luck, and don't cut your fingers of
    Keep them spinning,
    Bert.
    Thanks Basite,

    I will be cutting the disks at angles to match the curvature of the egg. Then lots of sanding. No filler.

    I have 10 fingers today. My plan is to still have 10 fingers next week. Keep your fingers crossed for my fingers.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  16. #16
    I took a headstart... basite's Avatar
    Join Date
    Jul 2006
    Location
    Mortsel, Antwerp, Belgium, Europe, Earth
    Posts
    3,226
    Quote Originally Posted by GMichael
    Thanks Basite,

    I will be cutting the disks at angles to match the curvature of the egg. Then lots of sanding. No filler.

    I have 10 fingers today. My plan is to still have 10 fingers next week. Keep your fingers crossed for my fingers.

    sounds like you have a plan

    here's some more inspiration btw: link to an egg speaker!
    Life is music!

    Mcintosh MA6400 Integrated
    Double Advent speakers
    Thiel CS2.3's
    *DIY Lenco L75 TT
    * SME 3012 S2
    * Rega RB-301
    *Denon DL-103 in midas body
    *Denon DL-304
    *Graham slee elevator EXP & revelation
    *Lehmann audio black cube SE
    Marantz CD5001 OSE
    MIT AVt 2 IC's
    Sonic link Black earth IC's
    Siltech MXT New york IC's
    Kimber 4VS speakercable
    Furutech powercord and plugs.

    I'm a happy 20 year old...

  17. #17
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Quote Originally Posted by basite
    sounds like you have a plan

    here's some more inspiration btw: link to an egg speaker!
    Cool. I especially like the ports in the stand. Nice.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  18. #18
    Loving This kexodusc's Avatar
    Join Date
    Nov 2003
    Location
    Department of Heuristics and Research on Material Applications
    Posts
    9,047
    Quote Originally Posted by GMichael
    I was wondering about bracing. There are no flat walls that will be able to flex. I’m using all rings. Circles are much stronger than boxes. The walls will mostly be 2 inch thick except for a few that will be 4 inch thick. Will there still be a need for bracing? If so, I could just make one ring a solid disk and then cut a bunch of holes in it.
    Well, I'll be honest, I'm not 100% sure how the fact it's a bunch of rings glued together will affect things as far as need for bracing, but I know a brace won't hurt. It's not the shape's ability to carry weight as much as the depth and density of the material. The pressure inside is going to make the cabinet want to resonate. The adjacent sides of the rings are coupled to themselves since they are circles so there's not really adjacent sides, but energy is transferred through each layer where connected by adhessive. I don't think bracing vertically is going to be effective or possible but a shelf brace is easy to do, just cut big holes like you said...in rectangular cabinets, they often look like window frames. I just make holes with jigsaw - they dont' have to be symmetncal or pretty.

    But I have seen many formed MDF or similar curved shape MDF cabinets cut like the layered rings you're using, - and bracing is used in these designs- which leads me to believe it's a good idea or those builders are also playing it safe.

    Besides, if small monitor and tower speakers are being braced with 5"-7" woofers, 18" subs probably need it too . 18" subs with 30 mm of xmax move a lot of air compared to 5" woofers in 3/4" mdf boxes.

    This is one of those better safe than sorry things. I know some builders that swear not to go more than 8" without brace. And bracing mattered big time in my first 15" sub which was 1.5" thick. I learned the hard way - it's easier to spend 15-20 minutes cutting and including a brace now, then adding one later once the box is sealed. The second cabinet I built I rabbeted spot for the shelf brace.

    I think a brad nail or two while gluing each layer might not be a bad thing either, rather than just clamps, assuming you have access to a brad nailer.

    Looks like you're well on your way though.

    Edit: One last thing - having 1 or 2 shelf braces inside also should help make applying damping material to the walls a bit easier.

  19. #19
    Super Moderator Site Moderator JohnMichael's Avatar
    Join Date
    Apr 2005
    Location
    Central Ohio
    Posts
    6,218
    Quote Originally Posted by GMichael
    Uh yeah.... It's because you've been in the medical field too long. That's what we'll go with....




    What's my excuse?



    Seriously it looks like a great design. Here is a photo of the Magico Mini cabinet and they had an interesting way of creating bracing by not removing as much material from all the pieces stacked together.
    Attached Images Attached Images
    JohnMichael

    Vinyl Rega Planar 2, Incognito rewire, Deepgroove subplatter, ceramic bearing, Michell Technoweight, Rega 24V motor, TTPSU, Ringmat Anniversary mat, Michael Lim top and bottom braces, 2 Rega feet and one RDC cone, Benz MC Gold, GSP Fanfare 3 w/PSU1

    Digital Sony SCD-XA5400ES SACD/cd, Marantz SA 8001

    Int. Amp Krell S-300i

    Speakers Focal 806V/Focal 800 stands

    Cables AQ Rocket 33's, Diamondback XLR's & IC's

  20. #20
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Quote Originally Posted by JohnMichael
    Seriously it looks like a great design. Here is a photo of the Magico Mini cabinet and they had an interesting way of creating bracing by not removing as much material from all the pieces stacked together.
    OOooooooo.... Nice!

    I like it.

    I am thinking of just leaving a couple of the rings as full disks and then cutting a bunch of holes in them.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  21. #21
    Loving This kexodusc's Avatar
    Join Date
    Nov 2003
    Location
    Department of Heuristics and Research on Material Applications
    Posts
    9,047
    Quote Originally Posted by audio amateur
    Kex, do sealed speaker enclosures generally need to be loosely stuffed? Does this also apply to sealed subwoofer enclosures?
    I have never had luck heavily stuffing a sealed cabinet but a lot experimenting is needed usually to find just how much. I tend to use a mix of insulation, foam and polyfill/acousta-stuff.I think this could be a personal preference thing too...not much of an answer, sorry.

  22. #22
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641

    OK Kex

    Since a few people seem to think that I didn't have enough bracing, here is the new design. Who's going to come over and help me drag this thing up the stairs when it's done?

    Is that enough bracing?
    Attached Images Attached Images
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  23. #23
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Cutting begain last weekend. There were a lot of setbacks at first, but now it's moving along well. I have 15 rings cut and the rest have all been drawn out. Just need to connect the dots and then I can start stacking.
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

  24. #24
    Forum Regular audio amateur's Avatar
    Join Date
    Mar 2006
    Location
    France
    Posts
    2,603
    I'd wait for Kex's verdict but it looks good. Make sure the holes in the braces are large enough. I'd say cut out the equivalent of the surface area of the driver or more in each brace to allow easy air flow between the different compartments of the enclosure.

    Keep it coming and post some pics if you can, me wants to see the beast in construction

  25. #25
    Class of the clown GMichael's Avatar
    Join Date
    Apr 2005
    Location
    Anywhere but here...
    Posts
    13,641
    Quote Originally Posted by audio amateur
    I'd wait for Kex's verdict but it looks good. Make sure the holes in the braces are large enough. I'd say cut out the equivalent of the surface area of the driver or more in each brace to allow easy air flow between the different compartments of the enclosure.

    Keep it coming and post some pics if you can, me wants to see the beast in construction
    The braces will look like wagon wheels. A solid center, 4 spokes, and a 2 inch ring/wheel. There should be plenty of room for air flow.
    I do have a question though. Should I have the spokes from one brace line up with the spokes from the other braces, or should they be staggered to brake up the sound waves better?
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

Page 1 of 5 123 ... LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Latest AudioReview Articles

Hot Deals

Latest News

AudioReview on Facebook