First DIY project for a guy looking to upgrade - multiple sealed 18s?

OK fellas, the time has come from this guy to join the DIY world. Kicking off my own project has been in the back of my mind for quite some time and after this weekend's GTG I'm more motivated than ever. Currently I own a slew of commercial subs including 2 JTR Captivators, 2 epik empires, ED a5-350, etc. I'm looking to start an experiment of my own and seek that ultra extension everyone around here seems to crave. After hearing a pair of LMS 5400's and a trio of Submersives, I'm sold.

Background: I've done quite a bit of reading on here prior to this decision. I'm fairly familiar with WinISD, boxnotes, the various home theater shack calculators, the eq-ing process, etc.

This will be the first enclosure I've built but I'd consider myself to be fairly handy with build/design. I do own a table saw, router, jigsaw, miter saw, circular saw (with guide), sprayer, various sanders, etc.

The new subs, once finished, would be in lieu of my Captivators in my basement theater. I do love the Caps and they will not be leaving my house! The Captivators will be moved upstairs to my living room. The viewing area of the room is 13x22 and the total size of this room is 16 (average width) x 44. Concrete slab, drop ceiling, some DIY bass traps for now, yada yada. I'm not in a rush and I want to do this correctly.

Obviously if I'm going to make this effort I want to use some decent drivers. I'd like to start off with a prototype unit and then expand to fill the rest of the room. I've been looking hard at the Mach 5 Audio UXL-18 driver. It seems to be one of the best values out there for what I'm seeking to achieve. Good power handling, decent sensitivity, and good value overall.

How difficult have the UXL-18s been to procure these days? It seems in the past the wait times have been less than ideal. Have the QC issues been worked out, reliably? I've followed HuskerOmaha's thread and I know he had his share of challenges. I suppose I should chat with him directly.


Here are my thoughts on a design approach: I've been toying with some models in WinISD and it seems to work well in a ~3.5 foot enclosure. This seems to give me the best low end extension down to 10hz while keeping excursion in check. Using Boxnotes I've come up with a box of 20w x 20h x 22d that accounts for driver displacement and some bracing as well. These dimensions give me a net volume of 3.57 cubic feet. I'll likely build the first unit out of 3/4" MDF with a double baffle up front and driver recessed. I'll be stuffing the box with some type of filland using a speakon connector in the rear. Ultimately I'd build 4-6 of these and place them around the room to smooth things out. I've attached some screenshots of what I'm working with.

Bracing - I'd like to use (2) 18.5x18.5 panels with a 17" or so circle cut out spaced 1/3 front and back. Is this overkill for this sized box? Should I stick with one brace, centered?

Edges - Will likely do a roundover on all corners to keep things smooth.

Finish - TBD, but likely something like a Duratex finish. Seems nice and relatively easy to apply.

Open questions:

To keep things simpler and making less enclosures, I'm toying with the idea of first building a dual opposed enclosure. Will I simply double the internal volume for one of these bad boys? If I'm going to begin placing them in the acoustically proven best position of my room (mid wall under my projector screen), I will really only be height limited to about under 28". Width wise I have about 62" inches to work with and depth and I'm not really limited. I'm trying to keep all this in mind for when I build multiples. If I go the dual opposed route, I'm hoping to keep the enclosure right under 6.5 net working cu feet which puts me to something like 22w x 28h x 24d. I must admit it seems that placing smaller enclosures in the room does seem a lot sexier though.

My current equipment: Denon 4311 receiver, miniDSP for EQ, omnimic v2, CHT SHO-10 LCR. I currently own Crown XLS5000 and EP4000 amps. I'll be adding to this stack as needed.

Feel free to throw in some thoughts/advise as I begin my journey. If I'm clearly overlooking something in my process PLEASE don't hesitate to let me know. Thanks so much in advance for your input and consideration.

Andrew

boxnotes for 20x20x22.JPG 64k .JPG file
uxl18 in 3.5 cu foot box.JPG 119k .JPG file
Edited by Gorilla83 - 10/26/12 at 6:39am

They are rated at 1200, so somewhere around that or slightly over? Although I do see a few others throwing quite a bit more power at them....looking for suggestions here from UXL owners? One option is to run an EP4000 bridged on each of them around ~1900 watts at 4 ohms.

I've only had a max of 3 subs in the room running at one time. With 1, 2, or 3 subs they all measured and sounded best mid wall. I'm thinking 4 subs would probably do the job, but I could always add 2-4 more? Pros/Cons of each design duly noted. I have to admit the Dual opposed is tempting if I can make it work. Can I get away with a slightly smaller shared volume (say around 6.5 cubes) if they're sharing space? They seem to model OK this way.

Agreed. I think 6hz would be fine though so maybe they should be pushed a bit harder.

Thanks for your input Josh. I actually have a Crown XLS5000 which is basically a mirror image of the CV5000 with a few less features. I also have a miniDSP would should easily handle EQ

I really do like the idea of the Dayton Drivers as an alternative though. Essentially I can buy 2 X of the daytons for the same price as one UXL or Sundown driver. This should give me a bit more displacement, even if it is a bit less xmax per driver. Do you happen to have decent T/S for this guy? The list I saw on PE seemed to be lacking. do you think 5-6 cubic feet is sufficient for dual opposed in this design? I'd like to see how it models duals vs. one UXL.


I think feeding 2500 watts per 2 drivers (2 ohm stereo) sound like a great combo with my Crown amp. Agreed on box size as being a natural limiter, now it's just finding the proper size for them.

Dual Dayton 18's in a 5cu ft box with 1800 watts (yellow) vs. single UXL-18 in 3.5 cu ft box and 1200 watts. Holy crap - am I doing this correctly? Dual Daytons FTW! dual dayton 18 vs single uxl.JPG 104k .JPG file

Four dual opposed Dayton 18's placed around the room?

Agreed and thank you! The good part is I have very ample LFE in the meantime until my project is done, so definitely no rushing.

Thanks Scott, you're the man. I did some modeling of my own as well - it seems like a 5 cubic foot dual opposed box seems to model the best. This puts me at about a 23" cube considering displacement for both drivers and bracing.The difference between 2 x Daytons vs. 1 UXL is NOT insignificant. It's looking like +1db at 10hz, +2db at 20hz, +4db and 30hz, and +6db at 40hz+. Assuming I can put 1250 watts to each driver, the pair (opposed) should be a STOUT performer, especially considering I can likely build each enclosure for under 650 including duratex finishing - possibly slightly more if I got with a higher end finish and/or a fancy grill.

Considering the box size will only be marginally bigger than the single UXL box, is there really any reason I wouldn't go with the dayton 18's over the UXL-18?

Pros for Daytons:
Cheaper to replace
Readily available from parts express - good warranty coverage and customer service
Twice the drivers means I can spread out the heat vs. a single driver

Cons
More space required vs. UXL (marginal and not really an issue in my case)
Edited by Gorilla83 - 10/26/12 at 11:59am