I don't know.... I'm just passing on the news.
The O-Audio 500W BASH amps are a better match for Shiva-X & Tempest-X but its over twice the $$$
They have an adjustable high-pass, single band PEQ & 4th order variable low-pass filter. Your into $239 plus shipping for them but if I where taking the time to build a sub, I'd spend the extra money.