My 120 watt KLH subwoofer which had been working fine recently started to
rumble very loudly on deep bass sounds. I tried adjusting the various
settings and checked all the wiring but to no avail. I took the cover off
and noticed no holes in the speaker. I have owned and used it daily about a
year and a half. If anyone has any suggestions on how I might make
adjustments I would appreciate it.

Thanks.

John