In room close mic measurement, how close??

Put the driver in the middle of the room. Raise it up if possible. Put the mic a couple inches from the dust cap. Sweep. Pull the mic back to about 6". Sweep. Keep doing that until you see the room. Probably can't get out past 6" unless your sub is well away from boundaries.

Turn it up as much as feasible once you've found that threshold which won't be to loud or you'll clip the mic or something in the system.

Is this a sealed sub or a ported sub?

Ah, good question Stereodude. I didn't think about that.

Randy, that's a little tricker. I would try by putting the speaker in the middle of the room and place it on the floor. Get the driver and port close to the floor. What size of driver? And how far away is the port? I'd then put the mic about 12 to 18" midway between the woofer and the port and lay the mic on the floor. Sweep. See how that looks. That will have captured the driver and port all in one. If the room influences the response, then raise the speaker up off the floor, put the mic 1" away from the center of the woofer. Sweep. Then right at the port. Sweep. Then hopefully your software will have a "match" and "stitch" function. Maybe do both ways, even if the further mic position works. That way you'll see the two separate outputs. Kind of depends what you're trying to do.

I'd try 12" away and try and capture both port and driver outputs at the same time. Unless you need to see the difference. You should be able to manage if you can get out in the room.