15" TC sound LMS build

I hope to start on a proper box build on the weekend for the sub I finally decided on. It was sold to me as a prototype TC LMS sub seems to be very close to the TC LMS-4000, Regardless it sounds fantastic in the quick small sealed box I built for it to test it in.
The plan is to put it in a ported box so I can take full advantage of the limited wattage I have to supply it with (EP1500) I need to to (or I'd really like to) keep it under 8 cubit feet. I've run it in WinISD in a few enclosures and it seems to do well in anything from a 7.5-9.5 cubic foot tuned to 18hz with little difference. So I'll be planning this out in the next few days and hope to start on it on saturday or sunday.
I really like the shape of the JL Gotham sub so I think I'd like to go with a shape very close to that. I was debating going with the stacked MDF or BB cut out to the shape but that'll be allot of wood and allot of waist never mind the time involved. So I thought if it's possible at all I would make a shell 3/4"-1" thick hallow out of 18 gauge steel and fill it with sand. Does the sound like it might work? I can dampen the inner steel with either fiberglass or dynamat if it would cause issues. This is just one of the few ideas that I have in mind and would be the easiest for me since I'm a bodyman by trade and form metal planels on a daily basis. The front top and bottom would be double thick (1.5") BB. Any ideas suggestion? Am I on the wrong path or maybe this will work?

And the only pics i'll have till I start cutting something up, since I'm not a computer guy.(no CAD for you )




Screen shot of the boxes I was modeling as well as the one the sub is in right now. And the specs I was given with the Sub Xmax is 38mm.



Clinton

I may upgrade my amp in the future but not for awhile, just don`t have the need at the moment.
For the PR box that`s the same as a ported box just no space wasted by the port and easier to retune no? I can`t see how there would be any difference and WinISD tends to model the exact same in either of the same size and tune. If you look at the WinISD above the sealed box drops the bottom end off very rapid compared to the vented. I was also basing the box on the tests on the Home Theater Shack according to the tests the only other DIY sub and only one commercial (svs ultra) that did better than a vented LMS 15" was it`s big brother the 18" LMS. Maybe I`m reading this stuff wrong or I have not found the right build threads, by all means I do not want to put the hours into a new box and have to redo it because it`s no the right type/size.

Anyone have any opinion on the use of a steel shell filled with sand?

Ok well I was running the model with a 6" port, took that into account. The 6`port takes about .5 cubic foot of space so that`s why the 8.5 cubic foot limit, need the space for the port. I`m not sure you would hear any port noise at the volume it would take to have any in the first place. But I can`t say for sure that`s why I wanted some opinions for some of the more experienced guys on here before I got to the final plan stage, start to build stage. Hope to get some kind of reply but if not guess i`ll wing it.

Ok well I guess I'll just go with my plan then since I haven't got any replys that say there would be any issues. Maybe I'll post some pics up when it's all finished up in a few weeks.

Thanks
Clinton

Thanks for input LB. Ill play with it some more in WinISD and see what i can do with the port AV. I Can't really use a slot port with the odd shape the box will be, if i can't get a port to work i can always just do a smaller sealed box and call it a day. Guess i should have thought about the purchase a little more, it just modeled so god in a 7cubic foot box. :/ Im sure everyone is sick to death of all the builds so im not going to bother doing a build thread, no point if It's just for myself. might post a pic when its done. Thanks again guys.

Clinton

Well I wasn't going to post any build pics since there a ton of buildso n here already but LTD02 asked me to post em up so here's a little progress.
I went with a sealed design again since the TS data I have may or may not be correct and I just don't want to spend the time to build something that "might" work. So this works our to approx 120 L after driver and braces, it will be double top/bottom and face 3/4" MDF. I wanted to go with a curved design but didn't want to waist 4-5 sheets of MDF plus the dust would be insane. So I opted for the DIY flexi MDF.

I used my home built panel saw to do the cutting and slits, at one point the bottom foot was catching so the slits went askew but ti didn't seem to effect the bend so no big deal.





The top and bottom inner panels were cut then laid on top of each other clamped and belt sanded to they match.




And a quick test to see if it was all going to work. That's as far as I got last night only had a few hours.




Clinton

Thanks guys, I'll keep updating as long as someone is looking and I'm not just talking to myself here.
Had a chance to take the pics off my phone from last nights work, didn't get too far but it's coming along without issue.

First thing I did was glue and nail the top and bottom sections on, I need to buy more claps since I'm not a woodworker at all I only have a few so that was fairly slow. Then I filled in the voids in the curved section. I saved alot of the MDF dust and just mixed that with Fiberglass resin to fill with. Worked really good, cheap strong and easy.




Then I smoothed out the top and bottom and glued/nailed on the second layer of MDF. Then I rounded it over, I know early in the build just wanted to see what it would look like. And started on the braces, I only got one main brace at the back build. It will have 4 horizontal braces on each side spaced evenly as well as a few vertical between them. Any idea if that would be enough or should I go with more?

Thanks guys.
Yep the panel saw was the first thing i built when we bought our house a few years ago. It's pretty awsome way easier than a table saw and hardly any roomtaken up.
Double top, bottom and front. Anyone think i need a magnet brace on this monster or should it be fine as is? Thanks for the replys so far.

Easy? I absolutely suck at wood work, wish I was better but it's just not my thing.
But progress none the less, Got time to cut some braces and glue them in. I went with a magnet brace, meant to make it bigger around as in side wall thickness but it turned out a bit different than planed. Still should be lots of bracing for an enclosure this size I think.
Braces an front panels cut out.




All glued in, I used construction adhesive to keep everything nice and strong.





Gave the inside a few coats of box liner to make sure everything is all sealed up and glued the front panels on.




So now it's just all finishing stuff which should be fairly easy. Few questions about some things I'm not sure on and need some opinions.

1. The connection terminals, I was going to put them on the bottom since it will have short legs. Anyone see a problem with this or maybe a better location?

2. I'm up 50-50 split on if I should build a lid on either side like the JL Gotham so the grill (If I make one) will be flush. Or should I just round over the edges and not worry about a grill?

Any help and or opinions would be great then I can get this finished for my birthday party next weekend.

Nobody has any thoughts or opinions? I get a chance to work on this again this afternoon, or I wouldn't be in such a hurry.

Thanks for input guys, yeah really wood work is not my strong point.


For me but I have a hard time deciding, either way in my mind would look good so it really doesn't matter. I'd build two cabinets just to see if I had the time, they are fairly cheap to build just don't have too much time to mess with it these days still have house renos to finish. (never ending )
It's going to get primed and painted with a high gloss finish that's a given since I'm part owner in a Bodyshop and I have never touched veneer in my life. Just unsure on the grill and if I should extend the front to incorporate the grill depth. I think I will since it will add a little style to the plan look of the enclosure. I procrastinate to much.

As in for box volume or for the spacing of the cuts?

Yep had the rare earth magnets sitting here waiting since before I cut the wood. Stainless Steel or aluminium grill is for sure the way I'll go, I was thinking a custom one like the grill in a 37 Ford just cause I'm a car guy.
I checked on the temp box I have the sub in which also has a 3/4" countersink. The rubber surround actually sicks out the furthest which is appox 3/4" off the flat of the box. So yeah I was thinking 1" at the edges curved out to 1 3/8" or so in the center, I'll have to see what looks good.

Wish I could tell ya I had a good formula but I just went with what made sense to me. I drew the radius/top overall shape out on paper full sized then measured what the inside and outside radius was. It showed I loose approx 1.25" for every 10" in length on the inside at the tightest radius. So I figured out how many cuts I would have to make to take that amount out at that length and doubled it. I did that so there was no maybe's because I figured at exact measurements it would be to tight to make the bend and I'd run into having to recut. It worked out well enough.
To figure out the area, I had a box drawn around the shape I had decided on for the top/bottom. I then divided up the empty space along with the 3/4" for wall thickness into triangles, overlapping rather than under so it would err on the side of less. Doubled that for the two sides and I get the area of the odd shape. The only other way I know how to do this is to find the area of an oval LxWx.8 and divide that by 2. Which was fairly close but a bit on the small side since the sides of my enclosure are not as curved as an oval.
Hope this made some sense to you I don't normally plan this stuff all that indepth I usually just come up with a quick plan and build, works most of the time. Oh and no I didn't use any water or anything to bend my shape, just ran some glue on the top/bottom and clapped everything in place and nailed it down.