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465L 14.5Hz Maelstrom-X Sonosub

29K views 66 replies 19 participants last post by  ironglen 
#1 · (Edited)
Here's the link to the planning and assistance prior to building:
http://www.hometheatershack.com/for...8158-lone-15-llt-dual-12-sonotubes-chime.html

Driver Brand, Model, Size: Exodus Audio Maelstrom-X 18" Subwoofer (dual vc 2 ohm)

Enclosure volume: 465 L 16.4 cu.ft

Tuning frequency: 14.5 Hz

Some prices are estimates:

Maelstrom-X Driver ~$400 Exodus Audio
Samson PG2200 amp $240 SamAsh
Samson S-Convert $35 SamAsh
24" ID, 12' sonotube $70 Shepler's Concrete Supply
8 1/16" ID, 4' sonotube $8 Lowes/Home Depot
3/4"x4'x8' birch plywood $40 Lowes/Home Depot
1 1/8" subfloor fir plywood $leftover scrap piece
10-24 2 1/2" allen bolts with hurricane nuts $12 Sutherlands
Crutches $1 garage sale
5/16"x2' (x3) fully threaded bolts with nylocknuts, flat washers $6 Lowes/Home Depot
71"x7' Black Carpet $35 Lowes
1 Qt Carpet Glue $10 Lowes
Polyurethane Adhesive $4 Lowes/Home Depot
Eggcrate Mattress Foam (Queen, scrap leftover piece) $10 Target
RustOleum Gloss Black Oil-based Enamel $8 Walmart
Miscellaneous Tidbits $? (a bit more than expected, for sure)
Subtotal: ~ $1000

Help from HTS members...PRICELESS! :T
 
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#2 ·
Automobile drivers gave me plenty of room on the highway...

Honey, you said it would fit in the corner! And be hardly noticeable!

Look your tubes over-and measure them! I got the right inside diameters (ID) for both, but you have to watch for ovalization? of the tube, which will give you an incorrect ID. Look out for creases and holes!?!

I also had a tube that was the joining of two segments, but I managed to use 6' of 'good' tube out of it.

While stripping the film, pull squarely away rather than at an angle and it will come off cleanly.
 
#3 ·
I used the wax liner to make a straight line around the tube for my jigsaw cut.

I bought the 'adhesives' and tested them on scraps to ensure compatibility/performance-this product adhered so well that the cardboard tube separated before the bond with wood even came close to failing.

The outdoor carpet glue takes longer than stated to cure, but is very strong once dry.

I made a circle jig for about $10 for my new router, 13A new vs 3.5A old one. It has a plunge base too, while I still used the old one to do roundovers without changing bits.

Measure twice (or thrice!) and cut once
 
#6 ·
I think mine will be blacker than black- maybe call it 'the black hole' :demon: I would have had it a few inches taller, but the carpet limited the tube to 5'11" and the corner space only allowed for 24" diameter tubing.

I told my wife about the 'stone column sonosub' a member built, and her reply was 'oh cool, I want to see it'. I am very fortunate indeed:jiggy:

The volume and tuning may be a tad off as I'm giving it a bit of leeway to account for port mounting, imperfect port calculation, etc. I wanted to ensure it met the HTS LLT standards :dumbcrazy:
 
#7 ·
The volume and tuning may be a tad off as I'm giving it a bit of leeway to account for port mounting, imperfect port calculation, etc. I wanted to ensure it met the HTS LLT standards
:rofl: Standards.........what standards? I hope I met the standard with 16hz. :dumbcrazy:

Looks like a fun project! Can't wait to see the finished project and read your BIG smile after you fire it up.

Matt
 
#8 ·
Thanks Matt. I'm sure your sub (and many members' on here) have all 'made the grade'.:yes: I've been back in school for a few years and my friends have moved on:sad: But my interest in electronics/audio has never gone away:dumbcrazy: I've been telling my wife how nice it is to have this excellent forum with exceptional people that are interested whether your system is small or large, and they especially enjoy helping you reach your goals. I've looked at so many helpful build threads, and now building my second, I hope that mine assists someone else in the future. I realize my carpentry skills aren't the greatest, but I can be creative.
 
#10 ·
It's in the factory! :neener: Really, it is. Exodus is sold out of Maelstrom's and trying to catch up on production. A sonotubes a sonotube, right? Tough to customize it much, I think, beyond different legs, coverings while retaining WAF aesthetics. For my garage/home office sonosub, I'm still contemplating covering it with a heavy metal band poster or a 'celebrity', perhaps a scantily clad joan jett or lita ford:sick: Seriously, I am considering an iconic poster of Hendrix or someone else, but not sure if I could clearcoat it on nicely without it warping horribly:ponder:

I've got a couple days off starting tomorrow and will be working on the port flares and orthopedic portion, I mean, baseplate fitting :bigsmile: before disassembly and painting :yay: I have a feature Kevin H. of Exodus/others might like...thanks for the interest!
 
#11 ·
neat project. I'm interested in what you are doing with the two different thicknesses of wood, and of course the crutches.

Gluing the carpet is probably the best way to permanently hold it on. I ended up using staples, and only stapling the joint where the two ends meet. One side of the sub is in the corner anyway and I'm not sure I will always want this carpet...so it's easy to just pull out the staples and recover.
 
#12 ·
Finished the port flares and endcaps :jiggy: (except driver hole drilling/mounting). I'll be sure to take good photos of the plywood(s). I'm using black outdoor carpet, and I'm not concerned about changing colors, so I figure I'll glue it permanently. I just using the -inexpensive- crutches in place of tubing- I'll work on that tomorrow before disassembling to paint. Glad this is taking a while since I won't have the driver for some time...
 
#13 ·
Glen, I'm just getting caught up now, great work so far. Hey, that's what I forgot... have you thought about using a high pass filter (rumble or subsonic filter) like the Reckhorn B1 or Behringer MIC2200? It's a simple way to make sure your sub won't get damaged by overexcursion below the tuning frequency... of course, depending on your simulation, you may not need it, but I'd think the EP2500 would be able to give it enough juice below 14.5Hz to have the potential for damage. I'm not trying to scare you, just wondering if anyone's brought it up yet.

Keep up the great work!!
 
#14 ·
Hey Owen,

Yes, Mike P pointed that out to me. I thought it would be alright with the low tuning, but maybe I should reconsider...

Speaking of reconsidering. I came across a company, sound solutions audio that is selling the mach5 ixl18 for $265 shipped (currently out of stock, it will be in stock again very soon) and I consider it as a good bargain that I thought I couldn't get (the mach5 site wouldn't ship to texas) and was kinda weary of foam surrounds, but it looks like many high-end drivers use them. It seemed to model well, just less output than a mal-x. Just thinking, and any opinions appreciated.

Also, I was looking to order some connections, etc and looked at parts express that has the 300 and 500w bash amps for, I believe, very good prices right now. Could I get one and use it for a while, then switch it for an ep2500? I could then use the bash amp for my massive 10" sonosub (it is currently underpowered with 110w).

Both of these changes would decrease my initial cost significantly, only the dimensions of the ixl driver looks to be different than say, a mal-x or rl-p18...
 
#15 · (Edited)
Glen, I've heard some very good things about the IXL. I think what sticks out for me (and I may be doing this wrong) is that the IXL has a 22mm xmax, and the Maelstrom has 33. The IXL's Sd is also slightly smaller than the Maelstrom, and I calculate 4.5L Vd for the IXL, and 7.8 for the Maelstrom. That's nearly twice as much displacement. In most real world setups, will a Maelstrom get pushed to its limits? Probably not, in which case the IXL should still deliver in spades. I'm not trying to dissuade you at all, because I'm sure both will make a sub worthy of :yikes:

Edit: Just looked at it some more, it seems like they are closer to even as far as cost and displacement when you compare 3 IXL's to 2 Maelstroms. But that's just me procrastinating at work and doing subwoofer daydreaming math.
 
#16 ·
Wish I had a way to compare through listening :wits-end: They both would have the capability to play low- the IXL just has less spl. The spl levels are so much more than the 10" I built, I wonder, how much do I need or will I use? Since it is for HT, I'm guessing the extra xmax comes in real handy:dontknow: Say, can I use winisd to model the output of my current svs cs-12 to compare to the others? (I'm at work until late)
 
#17 ·
Well, there are a few things to consider.

The Mal-X has almost double the displacement for less then half the cost.
The Shvia-X has almost the same displacement as the IXL for less money.

The other thing to look at is the Le which is MUCH lower on both the Mal-x and the Shiva.

Another item to take into consideration is the warranty and the after sales service which is AWESOME from Kevin!!

I almost went with the IXL but decided on the Mal-x and I am glad I did. I am sure I would of blown the IXL way past it's xmax by now. :)

Matt
 
#18 ·
The Mal-X has almost double the displacement for less then half the cost.
Half the cost of what? An IXL-18 is $265 and that includes shipping.

The Shvia-X has almost the same displacement as the IXL for less money.
Here are the Maelestrom-X, Shiva-X and IXL-18 modeled to Xmax with the appropriate high pass filters. There's a big a difference between the Shiva-X and IXL-18 as there is between the IXL-18 and Maelstrom-X.

Text Electronics Technology Line Electronic device
 
#19 · (Edited)
Half the cost of what? An IXL-18 is $265 and that includes shipping.
You are right Mike that made not sense at all. :) I meant if you take in consideration that the IXL is 220 and the Mal-x is 400 then you are getting twice the performance out of the Mal-x but at almost twice the price.

Interesting that the difference is that dramatic in WinISD between the Shiva and the IXL because when I did the math the Shiva was not to far behind the ILX in displacement.

Sd = 706.9 cm2
Xmax = 22 mm
(Vd) = 0.00155518 meter^3

Sd = 506 cm2
Xmax = 27
(Vd) = 0.0011132 meter^3

Using formula Vd = Sd x Xmax total

Matt
 
#20 ·
Thanks for the feedback guys:T I didn't think to model the three together: I just modeled the Mal-x, IXL, and my 10" aurasound spl paled in comparison, so the difference between the first two looked negligible. Things are a bit clearer now, thanks.

I'll stick with the Mal-x: it was my original plan to use it for my lone sub driver for a reason, eh?
 
#21 ·
Both of these changes would decrease my initial cost significantly
I wouldn't plan on any EQ, signal boosters, or high pass filters. That should help.

I wouldn't change driver plans....the Maelstrom just seems to be a in different league. If you need to go less expensive on the amp, I guess that would be ok initially, but I'd be a little weary of the low end FR of a plate amp. They typically have a high pass filter built in and it may rob some of your low end. Some have an adjustable center frequency for the high pass if you switch resistors.
 
#22 ·
Fired it up! The endplates, port, and tube are all tightly fitted- no glue yet. Played a little of the opening scene from LOTR fellowship- the driver was moving a whole lot, sound was...different than my svs cs12. Seemed like less sound, but more tactile. Heard a noise from the monster, so I turned it down- way down. Think it was my internal speaker wire, but the cone was moving quite a bit.

I'd bought a samson s-convert to up my signal when I tinkered with it on one channel going to my 10" aurasound, but now that it's bridged to the Mal-X, I have the s-convert turned almost all the way down, reducing the input rather than increasing it, while the amp (2200W) is turned nearly to max (as the amp literature said).

Funny, it doesn't seem loud and compared to the svs, it doesn't seem loud, but the camera resting on the couch was moving. Guess I'll pull it apart tonight and glue/screw it together so I can carpet it and fire it up again later this weekend:dunno:
 
#24 ·
BAM!:hsd: It's up- and the critters are running:hide: :demon::rofl: My SVS CS12NSD to the left and the Tympanic Titanic, as my wife calls it, to the right. A big thanks to Mike P and Steve C along with all HTS'ers that share their builds and help so generously:T
 

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#25 ·
These photos show how I used the crutches as the legs on the sub. I ended up recessing the aluminum tubes farther after test fitting. The 3/4" birch ply is exterior with the 1 1/8" tongue and groove decking ply doubled up to fit within the tube. The threaded bolts go all the way through, with a nyloc nut on the bottom that buries in the carpet. I figure a rubber cap could be used on a hard floor if needed. A drill press really makes this fit well, I wouldn't attempt this configuration without one.
 

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#26 ·
Here are pics of my flares, both internal and external. I set my port at a depth I wanted to cut to with my jigsaw and marked it. I then set my jig saw at a slight angle and cut to the line, slowly, followed by ever increasing angles set on the jigsaw in which I moved farther outward. Good enough for me as it is almost 7' tall and I can't even see the port. The internal was brainstorming idea-a maelstrom! Again, too bad noone can see it. I cut it out with a jigsaw too:bigsmile:
 

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#27 ·
The baseplate went great, except that the cutout diameter was too big (see Maelstrom X mounting thread). But thanks to Mike P, I believe it is mounted for good. After a test run, I think some wires were noisy, so I zip-tied a couple to the frame. The polyurethane glue is nasty stuff, I mean really nasty, so wear gloves. Use a small amount too, unless you have a large gap, perhaps from a jigsaw cut versus using a router, as mine squeezed most of it out and I had to wipe it away. The foam went in using some hot glue, some poly glue. The finish could have been glossier, but as it really isn't seen very well, I didn't do more than a light sanding between two coats, finished with a coat or two of clear polyurethane.
 

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#28 ·
How does it sound? Well, it sounds good, that is if I turn it down so it doesn't overpower everything.:hsd: So far, I've been testing it a bit with dvd material with waterfall plots that I found on the svs site, except the movies I have access to are often newer and are missing from there, eg Master and Commander. I do have LOTR and the Matrix series, and I've looked at a couple plots to see the freq in the LOTR and then played it back at increasing levels while viewing the driver's extension. So far it has done fine at levels I'll watch with the wife, where it is balanced with the mains. I don't have a spl meter yet. I ran audyssey and with the samson s-convert set at unity, my onkyo set the sub level at -13 I believe, so of course, I moved it up to -9 :yes: The samson signal lights light up, but don't stay on, and the clip lights have yet flicker-I guess there's reserve to spare:dumbcrazy: That's where it will stay for now unless I have it wrong. With the mains at -18 or so on LOTR, it easily produces what my svs cs12nsd worked hard to handle. The main differences seem to be the lows are more palpable while I don't notice it straining to fill my open room as the svs would from time to time. After a couple weeks sitting there not carpeted, once covered, it now exceeds the WAF:bigsmile:
 
#31 ·
Thanks guys for the compliments. I'm baffled why I'm getting the result I am: I've been using the Samson 2200W amp without boosting the input level from the receiver, and using no hpf. During the opening scene of LOTR Two Towers(when Gandalf falls with the Balrog), I had it at perhaps 18-16 on the receiver and it sounded great and the driver has alot of cone movement. I'm being careful since no hpf. Today, to test an SVS 500W plate amp, I connected them and turned it to max gain, hpf at 12hz (I figured 12.5hz would be ideal for a 14.5hz tune, no?) and turned the receiver on up to 6 as I figured it was safe. I believe that the sub output had less impact(and this is the confusing part), but cone movement was greater than anything I've seen previously. Could it be that the amp is clipping, and thus losing optimal control of the driver? I'm kind of in a dilemma as I'd like to experience all that this sub can provide, but also not willing to damage the driver.:scratchhead: Is there any way to know what kind of power the Samson I'm using?
 
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