i would not use that at all. depending on your speaker design. i dont know what you mean by vibration but if you are talknin about the knuckle rap on the speakers and can hear a sound change as you move up and downd the speakers that is normal and can be determined in the design. changing the cabinent resonance may not be the best thing to do. get a good pair of brass cones under them and see if this improves all the things you mentioned like tighter bass, it should. also correct speaker setup is about 80-90% of speaker problems. utilize the room correct and sitting position can make those speakers sound like you never heard them before. depending how old they are just see if drivers need a little tightening. only about 1/16 to a 1/8 turn, as to much tighness can effect the sound of the drivers if you have cone drivers as well as not stripping the screw.usually this needs to be done only once or twice depending how much you use them and how loud as well
BILL L
BILL L