Rear Ported versus Non Rear Ported floor standing

You should stay away from ported speakers. Unless you like an overly heavy bass. A speaker with a leaner precise bass response ( non-ported ) will give you far better transient response and the roll-off of 6 db per octave (versus 12) makes this ideal to place against a wall where you get reinforcement in the bass (as a bonus you actually get more ultra LF energy than a ported speaker at frequencies below the port resonance - so the bass sounds smoother and integrated rather than a mupy one note bass)

A sealed design may be the best way to go (if you can find one you like), and if you must place the speakers that close to the wall. If you go with a ported design...I'd go front port.

Dave

I'm using Spendor S8es which have a rear port and are only about 8" from the rear wall without any problems. (I had the smaller Spendor S5e prior to that and they had no issues either.) Spendor makes a point that their slotted linear flow port is designed to be less sensitive to placement near to a rear wall than some other designs. My experience supports that statement.

Of course, the best thing to do with ANY speaker is to try it in your listening room and see what you think of it before you buy.