RSD12D box - could it be better

[Towncar 10+ year member]

I am in knoxville towncar. Well the box seems solid but i will check it out some more. What kind of amp settings should i be messing with? The crossovers are at sensible settings but the HU crosses it over a little lower than the amp is set for anyway. The gain isn't set by the meter yet, its about in the middle right now. And i have twisted the phase all around hearing no real difference i assume its irrelevant for one sub or something.
One difference i notice between my rsd and the type-e's is that the e's hit each notice efficiently and seem ready to take on the next note before the current one is over, while the rsd seems a little sluggish and just kind of takes the notes on as it can.

First things first, you want to make sure the gain is set right. You may be clipping the amp as we speak. I suggest you get a dmm. Or if you want Ide lend you some help, as Im also in the area. Pm me if your interested.