Im on the road still (minor car trouble), so ill have to get back at greater length once im back in town but i can give a few quick answers for y'all.
I find that in order to deal with room nodes/resonance peaks, to play around with pulling the speakers out into the room a bit more, adjusting their toe in and the kinds of things that are behind them usually makes a more beneficial difference than to stuff the port (which tends to get the sound a bit lean for my likings). Upon full break in, the 90hz region settles down and you end up getting a bit lower bass out of just the orcas themselves to around 75hz once the FS of the driver fully drops down from the surround and spider completely loosening up.
One thing i can say from experience is that if you find yourself constantly fiddling with the controls to find the best bass per genre, then the system just isnt broken in yet, or perhaps it is not in the right position in your room to begin with (or you may be going for too high of a subwoofer level which will make it stick out in the mix alot more than its intended to).
However, the Orcas are intended to be a modular design in many ways, (including the ability to stuff the port). So while this tuning technique or that may not be not to my particular liking doesnt mean its the wrong thing to do for your space (or tastes). The point that i would most like to drive home is that they can definitely be played with to fit into a variety of situations with acceptable compromises depending upon the various room/amplifier setups.
Firstly, the most important point of adjustment is the distance from the front wall (or any similar surface) to the port on the back of the orca fullrange. This can be adjusted incrimentally and plays a huge role in being able to adjust for room modes and other idiosyncracies to each acoustic space (and also to get the right "richness" to the mix of bass/treble in the orcas. I usually recommend 1"-28" distance.
In our demo space i pull them out exactly two feet from the wall to get ideal midbass punch in that space (considering that i am using a sub as well). The speakers are roughly (iirc) 9-10ft apart and are slightly toed in ~5 degrees. The space is 13x25 and they are setup on the short wall.
In the case of a single sub, I place it right beside the left speaker (the one that is in the corner), and with the port facing out into the room (which is necessary because of the rather live nature of the corner of the room in our space). I set the dials at 9:00 for the gain and 10:10 for the frequency. This gives a nice "easy" sounding bass without boominess or undue power and it works with prettymuch every genre of music without adjustment. The RTA has confirmed these settings as well. Granted, it did take me a while to first find these settings and placement. I do tend to find myself adjusting the levels on a single sub system more frequently than on my double sub system as the integration is inherently a bit better with the double subs (for acoustic reasons, not for lack of power). For the double subs, the dials are in roughly the same spot because each sub amps' high level input section is only getting one channel instead of two, and you have two amps and two drivers working which balances things out to the same relative level. Once i get home ill put up some photos of what this looks like.
In rather damped/carpeted rooms, i have found myself turning the gain all the way up to 11:00 and the frequency as far as noon even in some cases. Most people find themselves somewhere in the middle of all this. But my steadfast advice is to echo Dan- start low and come up.
In the shop stereo we use just a sex amp and orcas w/no sub. For space reasons i push the orcas all the way against the wall and spread ~14ft apart and they make lots of bass and respectable volum for the whole 25x25 space. I have used a sub down there in the past and the settings were a bit higher than the one upstairs. 9:10 gain and 10:30 for the frequency because theres alot of stuff in the shop, though its mostly hard surfaces (lotsa orcas)
In summary, the four main points of adjustment on the orca system are meant to be really easy to access, and most importantly, are meant to work together rather than seperately: distance from the front wall, toe in (if any) and of course the subs' placement and sub amps' settings, which should usually be kept easy to reach so you dont have to bend over to be able to adjust the dials.
Cheers!
Clark