Does Plugging Bass Port Affect Pace, Rhythm and Timing?

Mine are about 6" from the wall right now.  I'll try moving them out 4 more inches first before plugging the ports to see what that does. The only down side is esthetics - having the front of the speakers out over the edge of the shelf. But I could learn to live with it if the sound improved dramatically! 

OK, I will do that, and see how it works out. I don't have the original port plugs, but I do have some large chunks of foam material I could use (or just go with a pair of socks). 

OK, guys - I plugged the ports, and it really reduced that mid bass bloat by a lot. The music is much more balanced now, and those sweet highs are much more to the fore. I think I'll live with this configuration for a while before I try anything else like moving the speakers from the walls with and without plugs. Thanks for all your help!

Didn't think of that. I may try that!

I found out something interesting. The muddiness seemed more than anything else traceable to the fact that the tweeters were a good 12-15 inches above the height of my ears while listening. I tried tilting the speakers down by inserting a shim on the rear bottoms. This helped some - but when I turned the speakers over on their sides - voila! Now that the tweeters are almost even with my ears, the high frequencies and mid-range really came alive.

I didn't realize tweeters of this sort were so directional, but apparently 15 inches off axis is enough to severely attenuate the highs. I still keep the ports plugged due to the closeness to the wall. Pretty well balanced now, although I may have done something to the imaging by turning the speakers over on their sides - more experienced members than myself may be able to chime in on this.