25hz Infrasonic Filter Recommendations?

[subnet]

Hi all, I've got a kenwood 7205 amp (doesn't have an infrasonic/subsonic filter) and am just getting ready to purchase some kicker solo-baric 15" subs, does anyone have recommendations for a 25hz filter or sound processor of some sort to put in place? Obviously I would prefer it to be on the cheaper side, but not at the expense of sound quality - for example I've heard that although the the f-mod is inexpensive it can muddy up the bass. Any thoughts?

 

[subnet]

ok so with the online research i've done i came up with the following options that have an infrasonic / subsonic filter, any comments?

outdated - hard to find with no easily available replacements yet have the features i'm interested in:

phoenix bass cube gold
maxx bass

current - readily available, potential replacements to the above:
maxx sonics
hifonics bx-pro2 / bxi-pro2
hifonics mx-3
hifonics hdbr

audio control epicenter - will modify the bass frequencies, can order a variety of subsonic filter range plug-ins. i would prefer to stay out of processor that is changing frequencies however lots of people are recommending it so it's worth mention/consideration.

there's of course also the harrison labs fmod which is strictly an infrasonic hpf however i am hearing very mixed reviews on its quality and i don't want to put something into place that's going to muddy anything up.

am i missing any that are better around the same price range (e.g. $200 or less) that i should consider, or do you have comments on any of the above that you have used yourself with a decent 12" or 15" stereo sub system?

i'm leaning towards the mx-3 as it is reasonably priced, has an adjustable infrasonic filter, parametric variable band/width.