I'm guessing that ISF is supposed to be the infrasonic filter...if not, ignore what I'ma bout to say. I'd leave it at 25 since there typically isn't much information there and I wouldn't think your system could take advantage of any tracks that played that low.

The LPF looks fine where it's at but you can go as high as 100hz or 125hz in my opinion. It really depends on what your mids play. Play your sub too high and it'll muddle your sound. You'll definitely know.