Sounds like an enclosure issue to me.
Either the box is too large, too much port area, or playing too below/above tuning.
could be lots of problems... to big.... wrong port... ect.....
could be tuned higher than you think.... mathematical errors are quite common when building boxes and measurements //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif