Booming bass from WP6

Perhaps your sitting in an area affected by a standing wave. Try moving your chair and see if there is any change. Ditto your speakers. If you want specific help you can post your room dimensions and indicate where your chair and speakers are now located, or do some research into room acoustics in the archives on this site, in Audio Asylum FAQ's, and/or look at the Rives site.

If your condo has a common wall with a neighboring unit, you may actually be hearing the booming sound of a broom handle being pounded against the other side of the wall.
It took me a while to identify the characteristic leading-edge "slam".

It's probably true. Your room is too small for the WP6. A speaker that size really needs room to breathe. I wonder how the cubs would sound in there though. Small rooms need small speakers. I doubt that any full range floor standing speaker isn't going to come off sounding "boomy".

Newbee already mentioned us (thank you), but I wanted to be sure that you found this part of our site:
the room simulator
This allows you to put in your room dimensions and move the speakers and listening position. Watch the frequency response graph below 500 Hz. You would like to get a good flat response. The WP6 is not in the database, but the Sophias are and should be a reasonable replacement for this exercise. Placement can improve things to a degree, but in your case it is not likely the cure.
In a room that small there are relatively few modes at the lower octaves and the result--even with good dimensions (in terms of ratio) is boomy bass. The two alternatives is a smaller speaker that is less likely to excite these modes, (or at least to a much lesser degree) or to use a device such as our PARC, which compensates specifically for this one speaker-room interaction problem.

Have you tried stuffing something (like a sock) in the port to cut down on the speaker's bass contribution?