That's awesome, I always forget about the DEEP knob. My old DB680 had a deep switch I liked, but it didn't have a [minus] setting, just flat, + and ++.
Is the 3012 in the ML112 high passed at the crossover at all? I guess my question is whether I even need to worry about trying to wring max volume and protect speakers if I'm using a Valkyrie and pair of ML112's...
edit: More specifically, if I were to buy an HPF to fix my current rig would it bring any tangible benefit to the planned new rig?
From what I've heard, the Fdeck HPF is very good. Whether or not it would benefit a Valkyrie/ML112 rig would really be up to your own ears. It's never a bad thing to loose those sub-sonics as long as it doesn't compromise the tone you are after. Would it really be necessary? I think that it's not really an issue because of the DEEP control on the amp. If you are really pushing your drivers too hard, then your ears are going to let you know that. Rolling off the DEEP control and boosting the BASS control instead should really cut those sub-sonics out quite nicely.