Finally I bought Ryhtmik Audio's subwoofer kit which includes bash ampilifier and 12'' driver. Kit is direct servo and blaa blaa.. more info you can find from:
This sub gives around +100dB pure bass in the room. Unfortunately amp is too small:
After order I figured that I need a enclosure for driver. :D
I study in vocational school (Amis) so I have chance to do anything what I want for free so I decided to do enclosure from steel. Cylinder is nice shape and hottest trend nowadays. Soo I made cylinder from 2mm thick steel plate. Diameter is 370mm and height is 580mm
Using the Mangle machine wasn't so easy as I expected. Cylinder needs more welding and grinding...