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Discussion Starter #1 (Edited)
And with these photos I officially start my build thread!

You really don't understand how big this woofer is, till you see it in person. It's so big, it's almost perverted. :bigsmile:











I've got two other projects going on right now, I'm going to push one off, but I have to finish the second project as a small wad of cash is counting on me finishing this on time. I hope to be cutting wood for the Maelstrom late tonight!
 

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But why build it sealed when you can just cut a 10" hole and mount a port in there of 25"

on my modeling you'd get 124db at 20hz

:R
 

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But why build it sealed when you can just cut a 10" hole and mount a port in there of 25"

on my modeling you'd get 124db at 20hz

:R
Couldn't he get that result with a sealed as long as he has enough power to do it?
 

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Not in modeling. He might acheive it with room gain though. Still sealed requires more dampening and bracing than ported and at that size porting is a synch.
 

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awesome. i don't like the front gasket though! I remember how long I flipped cuz I thought my 15" L7 was so big, then my IB3 18".... I can't wait for mine!

port it. No, you can't get the same output with the same power from a sealed box as a ported box. A ported box uses the back 1/2 of the driver to double the output at tuning.
 

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15 cu ft seems a little big. 9 or 10cu ft sealed would be perfectly fine and the size I would use with high power. Are you using a bridged EP2500 on it?
 

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Discussion Starter #9
15 cu ft seems a little big. 9 or 10cu ft sealed would be perfectly fine and the size I would use with high power. Are you using a bridged EP2500 on it?
Yes, I'll be using my EP2500 on it (sorry, I forgot to put that at the beginning of the thread).

Keven recommended 12 cu ft, but I have space for 15cu, so I figured I'd just build it a little larger.

Any advantages of building it slightly smaller?

Unfortunately, I've not had time to cut any wood yet. It's killing me having this beast here, but have other family commitments.

Since I'm on vacation this week for my birthday, I'll have plenty of time to get it built up and done! :T
 

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Discussion Starter #11
i know everyone keeps pushing you around. my HO has always been build it as large as you can and tune it as low as you can. my 2 pennies.
Seriously. It's like, ask 20 guys and get 20 opinions.

I figured it was a safe bet to go with what Keven recommends, and maybe a little larger.

I'd love to do a 20 cubic tuned to 14Hz or something fun like that, but that would be more space then I'm willing to give up right now. I've always appreciated the sound of sealed enclosures, and Kevin recommended sealed, so that leaned me in that direction. Just because everyone wants to see a ported 21", isn't a good reason for me to build one! :ponder:
 

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If you have size/dimension information directly from Kevin stick with his plans. He knows his speakers better than anyone else :)
 

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Seriously. It's like, ask 20 guys and get 20 opinions.

I figured it was a safe bet to go with what Keven recommends, and maybe a little larger.

I'd love to do a 20 cubic tuned to 14Hz or something fun like that, but that would be more space then I'm willing to give up right now. I've always appreciated the sound of sealed enclosures, and Kevin recommended sealed, so that leaned me in that direction. Just because everyone wants to see a ported 21", isn't a good reason for me to build one! :ponder:
Ha! Drive on.... you are doing fine with what you are building.

Kevin Haskins
Exodus Audio
 

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Great build to follow.

Have fun and warn your neighbors:T
 

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Discussion Starter #16
Ha! Drive on.... you are doing fine with what you are building.

Kevin Haskins
Exodus Audio
Thanks Kevin.

3AM Last night while I was cutting the last of the outer panels and doing a test fit to see how big this thing is really going to be....I was starting to doubt my plan to go large sealed.

I'll just build it and see what comes. If I'm not happy with it, that either means I need to build an LLT, or go with TWO of them! :blink:
 

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Discussion Starter #18
For my birthday...my fiance gave me.....a cold. :crying:

I pretty much slept through my birthday, but got some work done on the box today. I was going to go really extravagant with my box joinery and show off my woodworking...but my **** is dragging so bad right now, it's all I can do to just build the thing.

I have to say....building a box this large, is hugely different then building boxes for car audio, or even guitar cabinet building. I'm used to being able to swing a board around to work on it, or hell, even moving a smaller panel is easy...with this monster, I walk around to the other side of the project to get something done! YIKES! And I have to say...if you're a little off on a cut with a small box, it doesn't show up. If you're off on a bigger box, that 1 degree of variance at the end of a 41" long panel could be 3-4 degrees off. And with the tools I had, I found I have no way of really truing up a bad edge to make it a perfect 90 with the sides. My cuts were within 1/64 consistently. I spent a lot of time tuning my table saw to get that way. But the factory edges...well, they were off by a bit here and there from the factory. I miss working on MDF! (except for the dust!)

And my last lament before I go on to build photos...I'm so spoiled by MDF. Cheap plywood is far from dimensionally stable, and my panels had a slight bow to them...which, of course would never show up on a 4cu ft box...but on a 15+ box, yes, you can see the bow in the panels!! :hissyfit:

Alright, cold induced moo fest is over, now for some progress. I kept this build really simple because I simply wasn't feeling up to an extravagant build, and if I don't get it done this week, I'm not sure when I'll have time to get it done in the near future. So here we go!


I absolutely love this ruler from Incra Tools. I have no idea how I got along without all these years...It helps keep me *very* accurate. I just wish I had a 24" version for this project.




Other key pieces that help keep this accurate and safe, is a quality table saw blade and splitter, on a zero clearance insert plate.




After I cut the panels I give them a quick sizing up...this is the part where I was up till 3AM wondering if I maybe should have gone with a smaller box, or ported box.... analysis paralysis! :unbelievable: Thanks Kevin for keeping me on track. I still have some questions in my pre-build thread that never got answered though.





Next I started on the bracing. I wanted the bracing to interlock. This is another part where I got really moo at the cheap plywood. I measured a panel and was pleased to find it was bang on 3/4". But then after cutting all the slots for the interlock, I find that they vary by a full 1/8" :rant: I saved weight on the build, but I think I'm going to reconsider cheap plywood in the future.

For the slots, I cut them on the table saw, then chipped out the wood with a 3/4" chisel.




Then using the tools on hand, I drew out the "window" style cutouts.




And started cutting! That Montogmery Wards jig saw was purchased by my parents when they bought their first house back in '81. I literally had to tighten the screws on it after every cut-out, and it's stuck ON all the time now...so I used a power strip as my on off button...but 1.5 hours later and I got the panels done!







And sizing up again.





I'm going to use a real thick construction adhesive to make up for the slop in the wood variance. I ran short on full panels, so I have one quadrant I'm going to piece together from cut offs after I get the main panels and bracing glued into the box.




Starting to glue up! I wish had more clamps. As it is, I have about $400 in clamps, and it wasn't nearly enough to glue up as much as I wanted in one sitting. I needed a break anyways...my nose is running.




Some fun shots.








I'll have more after I rest up and have some dinner. I hope to put a couple more hours in tonight getting a couple other panels glued in. I'll probably be putting off routing the face panel till tomorrow. I'm too bushed to wrestle with a 3HP router tonight. :D
 

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Discussion Starter #19 (Edited)
Hmm, I missed a photo.

Here is the last shot showing where I am now. This also shows the quadrant I'm missing due to running out of full panels. The front right is where the driver will go, and I'm going to piece together some bracing from cut-offs for that gap behind the driver.

 

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Discussion Starter #20
So at this point, I have a couple questions that didn't get answered in my build thread.

Do I line the walls with foam of some sort, like the egg-crate foam?

Do I stuff the open spaces with polyfill or "deep pockets" brand pillows?

Do I need any bracing to hold the magnet of the driver up?

Do I need to add more bracing between the existing bracing?
 
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