I have designed an enclosure (using Torres and WinISD) for my Sundown SA-12 (not built yet), which is 2 cubic feet tuned @ 35 hz:


P.S. I know the 6.25" measurement is bad it's a mistake in the picture I found in this forum (which is almost the same as the one I designed).

But then, I found another box design (I don't know what type of box is that) which seems pretty nice:

Cody’s Sundown SA-12 enclosure, engineered by PWK | MiltonBilt

So I have a few questions:

1. Is my box perfect for my system or I should consider another design (just like this one)?
2. Should I put 45 degrees corners (for bracing and sound)? If yes which width?
3. Will DAP ALEX PLUS Acrylic Latex Cault Plus Silicone be ok for sealing this enclosure (I will be running it summer like winter)?
4. Where should I put bracing and what kind (I know nothing about bracing)?
5. Where can I learn box design (like transmission line or bandpass) other than simple ported ones (like bass reflex)?

P.S. I am running this subwoofer with an Hifonics BRX1100.1D amplifier @ 1 ohm and I don't want to buy a design from anybody! I want to learn first!