I dont know what is good for you. But if you are citing the prbm you specified, What I can suggest is to put the tone (treble/bass) control of your receiver to the DEFEAT position (extreme counter clockwise), put off any loudness switch. Then from there, start with the TREBLE, slowly turn TRB clockwise until you want what you are hearing. Do the same for the BASS next. If it is still boomy, use small gauge of speaker wire to further tone down boominess.
ABove is to avoid ur stated prbm. There is not much u can do after the above experiment. If I have to force the issue, I may even open the speaker baffle and check whether there is damping materials inside, especially at the back of the driver - and experiment with fill materials if it does not have any.
