Monitor Audio RSW 12 SubWoofer Meets The THX Select 2 Plus Standards???

Hi there from Greece.
My name is Cris and for the last 3 years i own a Monitor Audio RSW 12 SubWoofer.
For those who don't know which is , look here:

http://www.monitoraudiousa.com/support/past-products/silver-rs/rsw-12/

I wonders if that Sub meets the THX Select 2 Plus standards , because my amp which is the Pioneer SC LX 75 (SC 55 for USA) has a setting in the menu if my Sub meets that standard.
It's specifications are the following:

Lower Frequency Limit: 27 Hz (EQ1); 21 Hz (EQ2)
Upper Frequency Limit: 40 - 120 Hz (Variable)
Low Pass Filter Alignment: Active 4th order 24dB / octave (2 stage filter)
Power Handling (RMS): 500 W (RMS)
Amplifier Classification: Class - D Digital Amplifier
Drive Unit Compliment: 1 x 12” C-CAM® Sub-woofer driver featuring triple suspension and 3" long voice coil
Cabinet Design: Sealed cabinet with internal bracing
Product External Dimensions:
(H x W x D)
340 x 340 x 370 mm
13 3/8 x 13 3/8 x 15 5/8 inch

Weight: 25.5 Kg (56 lb)

What do you think?

2 months ago i was ready to chage it with a Velodyne CHT 12Q in order to achieve better results.
Would it be a good move?
Edited by Blind Guardian - 1/28/13 at 2:27am

Hi & thanks for your answer.
I did not put my question properly.
First question is about the THX Standard

And next is my other question if is a good move to change it with the Velodyne one.
I mean will i find better bass with a SubWoofer like the velodyne or with something at maximum budget 800 $

Thanks