I spent 1h11m total on 11/20 - 11/22 applying three more coats of Duratex. I turned the sub once between each coat, so the sides all have 3 coats total, and 4 coats on the back. I put 3 coats on the access panel outer surface, too. I had previously painted the backs, sides, and flanges of the access panels with normal (non-Duratex) white paint+primer, which is the same stuff I used on the inside of the horn.
On 11/22, I installed the terminal cups and soldered the wires. I had some 3/4" wide black foam weatherstripping left over from my THTLP build
, so I tried using that for the access cover. However, when I started screwing down the access panel, the weatherstripping proved to be too thick. It would have been excellent if I had made the flange a little deeper, but I really did not leave much room. I ripped the weatherstripping off the flange, and did my best to scrape it away. That stuff really sticks well, and there was still a lot of residue left, but I figured it would not be a problem. Finally I used some highly compressible gray foam 1/2"-wide weatherstrip I had left over from the handles on my Econowave SR build
. That stuff does not stick nearly as well as the black foam weatherstrip, but it worked out fine. The lesson learned here is to make sure you recess your flange enough for the good black foam weatherstrip -- it seems better if it will fit.
Here's a pic of the access panel after installation:
And well, that's it! With 2h32m spent on 11/22, the final total comes in at 40h28m
to build my two AutoTuba subs. It may be the slowest AutoTuba build ever, but I like putzing around in the garage and playing with tools. And I'm running out of space for the projects I have already built, so I don't want to be too
prolific out there.
Last night I hooked them up to my new Crown XLS-1500 amp for testing. The Crown amp worked out nicely -- easy to hookup to a home stereo with RCA inputs and binding post outputs. I replaced the Behringer A500 that I was using to power my THTLP, and ran the THTLP off one channel and the two AutoTubas off the second channel in parallel. I used a y-cable to feed both channels. The fan in the amp turns very slowly and is virtually inaudible, even after running it hard for a while -- no mods required for home use. In hindsight, however, the iNuke3000DSP might be a better option -- the fan mod looks easy enough and doesn't seem like it would lead to thermal shutdown under practical loads, and it would be nice to have the DSP features, even though you need a Windows computer to program it. Hmm... I am tempted to pickup an iNuke via Guitar Center's Black Friday sale.
I haven't really had an opportunity to give the AutoTubas a fair audition, since my system is EQed for the THTLP (Anti-mode 8033 box + Audyssey XT in the receiver). But they work and make bass, with no weird sounds (that would indicate interior air leaks) or access panel air leaks. My unfair, uncontrolled impression is that the AutoTubas seem to have really good "chest hitting" impact, but the deeper extension of the THTLP is very noticeable, even with music. I have been listening to bass-heavy music, though. I think the additional power of the new amp has helped the THTLP performance, too.
(I still need to touch up a few spots inside the horn with white paint, after sanding off some Bondo. And maybe paint the glue squeeze-out, too. But I'm calling these "done".)