I have bottom ported OHM Walsh 4's sitting on carpet in a well damped room. End result is accurate but not very dynamic sound.
When speakers are placed on 16"X16" acrylic bases the sound changes dramatically; dynamic sound and considerable more bass, mid-bass not as accurate with minor coloration in male and female voices.
However, the overall satisfaction level is greater with the speakers on a solid base but I do need to tweak that mid-bass