BillFitzmaurice.info

What's up everyone? I'm back with my Titan 39 build thread. The goal is to build 8 of these over time. I started this one about three months ago but got busy with kids, work, and the wife. Wow, did that plywood warp!

This build actually took me substantially less time than the Otop 12. I found it took the longest to cut out all the pieces. I ran into some issues, though. Even after triple checking the plans, ensuring each piece was cut to perfection, and triple checking ng the layout on the right side was correct, I screwed something up. Panel 3 was approx 2" too long, panel 4 length had to be decreased from 9" to around 7", and panel 6 was too long as well. I realize it was probably the layout that was screwed up but I found the plans to be a little confusing on this front.

"Parallel lines are drawn ½ inch to the outside of the first five lines per diagram 4." I found this confusing and obviously made a mistake somewhere. At any rate, I was able to work through it. I realize the output will probably be affected but my crowds will never know the difference. And if the cab is affected too much then it's a sheet of plywood, a tube of PL, and two afternoons wasted for the lesson learned. Without further adieu.

More pictures

I like the idea of wheels on both ends. Roll to the truck. Tip up, and roll in on the other set. A bit more awkward with my tubas...

Yeah the idea for wheels on both ends was in the plans and it's really handy. The Titan 39s are not heavy by any means, but they can get that way alongside a full PA system worth of lifting. Don't know much about tubas except that they're just as amazing as the Titans!

Looks good

Hey, there you go!
Are you going to batch out the rest?
Consider that the driver is on the inside of the chamber lines. That would mean that you place the panel on that line so that the chamber stays the same size, and then draw along the other side of the panel (which would be the outside).

ACUA wrote: ↑Mon May 27, 2019 10:30 pmLooks good

Thank you

Tom Smit wrote: ↑Mon May 27, 2019 11:42 pm Hey, there you go!
Are you going to batch out the rest?
Consider that the driver is on the inside of the chamber lines. That would mean that you place the panel on that line so that the chamber stays the same size, and then draw along the other side of the panel (which would be the outside).

Thanks for the clarification, Tom. That'll help me out tremendously since I won't have to stand there and scratch my head.

I do plan to batch them out. I will probably do three then four at a time. Now that I have this box figured out the rest should go smooth. I plan to do it over time though because I can build the boxes much faster than I can buy the 3012LFs.

Parts express was out of stock for awhile. But now they're back and they're $20 more expensive. And since I don't have an immediate need for these subs, it's hard to justify ~$1600 in driver costs to the wife. Haha!

Thanks again!

The 3012LF came in today. I gotta say I'm a little impressed with my measuring skills. Lol! I sized the driver holes with the technical spec sheet and it worked out perfect. That driver fits tighter than a gnat's ass. Also, my flub with the panel placement didn't hinder the driver installation. I'm sure it will affect the output since the driver chamber has been slightly reduced, but I'm really not smart enough to do all that math. Next, I'll fit the access cover, seal it, and test.

At any rate, here are a few pics of the driver fitment.

Looking great so far

You don't want to undo that driver, but they shouldn't be a tight fit!
Heat makes metal expand right? If it's got no where to go, it will do something else, like break itself, or the cab.
Also, if needs be, how do you get it out if it's tight?
You can see your pencil line for the driver, make sure you cut out to that line for the rest

I'm also a little worried about how much you trimmed from the upper flange - there is only a tiny bit left to seal with the driver cover at the top of the half-moon. I remember not cuting that at all on my T-39, and I don't see it trimmed in the sketchup model.

Grant Bunter wrote: ↑Thu May 30, 2019 6:07 pm Looking great so far

You don't want to undo that driver, but they shouldn't be a tight fit!
Heat makes metal expand right? If it's got no where to go, it will do something else, like break itself, or the cab.
Also, if needs be, how do you get it out if it's tight?
You can see your pencil line for the driver, make sure you cut out to that line for the rest

I should've been more clear with my redneck slang I guess. Haha. What I meant when I said it fits tighter than a gnat's ass, is it's a perfect fit. There is approximately 1/32" space around the driver to allow for expansion. In the plans it just says to cut it so it is slightly larger than the driver basket. If it needs to be larger than that please let me know. The last thing I want to have is a 50 lb paper weight.

Thanks for the tips, Grant. I'll be more deliberate in my next builds.

billkatz wrote: ↑Sun Jun 02, 2019 11:43 pm I'm also a little worried about how much you trimmed from the upper flange - there is only a tiny bit left to seal with the driver cover at the top of the half-moon. I remember not cuting that at all on my T-39, and I don't see it trimmed in the sketchup model.

You're right. It doesn't say to trim it in the plans. It says that if the driver won't fit, then install the top horizontal brace with screws and gasket tape in between to seal the joint. I wasn't real comfortable with that seal. And I saw elsewhere on the forum where someone else did a similar technique...I ripped it off from them. Also, I ensured that I have at least 1/2" for my gasket tape.

You have cause for concern and it will be a point of attention for me. I'll report back how it works.

I haven't glued it down yet. So if it doesn't work then I'll just replace it with a piece that hasn't been trimmed.

Thanks for looking out.

Bigcox4002001 wrote: ↑Sat Jun 08, 2019 9:59 pm There is approximately 1/32" space around the driver to allow for expansion.

Ohh cool, that's great then. I thought you meant tight!!!!

Bigcox4002001 wrote: ↑Sat Jun 08, 2019 9:59 pm Thanks for the tips, Grant.

Always a pleasure

It's been a long summer. Moving, relocating a family member, 6 weeks of 12 hour days and no weekends, exercises, inspections...all the things that come with being a military leader. In the end though, we're all settled and the first Titan 39 is done. Far from perfect, that's for sure. But so was my first Otop 12. The next three will be a much smoother process. I'll have to wait awhile on those since I have three gigantic, ancient Philco radios I have to refurb and a car to get ready to sell. But once all that is over I'll be back on track. Thanks to all that have helped along the way! It's all done save for the grill.