I've had a side hobby of making home theater subwoofers out of car stereo equipment. It's difficult to find a balance of good musical bass reproduction as well as the lower frequencies proper for home theater.
The newest build is tuned to 29hz which is the lowest I've found I can still keep a balance. If I go below that which is better for the HT aspect, things seem to drop off too low.

I've recently made a couple out of some RE Audio subs. It's a relatively new brand that has impressed me.

I know I'm not the only one thats done this, I wanna see some other set ups


I did a few videos of mine recently

 

Wow, how does it sound for movies and games through. A friend was trying to convince me to make one but decided not to. I bought a $200 BIC America f-12 from Amazon which sounds great for movies and games.

For music it sound weak though. Don't know why.