JDsr

Ok I may have the answer for you. Not sure that this is what is being to referred to as a ground isolator or not , but I found a simple ground fix to the hum. I purchased 2 r 115 sw and had both humming hence odds of a fault were not typical with the unit. I put 2 screw slide ends on a wire to test this ground issue after seeing the ground isolator theory and had success. Attach one end to the sub by simply loosening a screw on the rear amp panel. I attached the other end to a screw i loosened and re tightened on the receiver and presto it was gone on both subs. Now to decide how much it bothers me that one sub has a functioning LED light and the other doesn't lite up..... Grrrr. Never thought I would have multi issues with a couple of high end Klipschs. I have had synergy subs for many years and was tempted by the 400 watt 15 and I will say a pair of these are beast... Also FYI my units are powered through a power filter and cap power unit to clean and protect the attached hi fi hardware so I would of never thought this possible , but I guarantee if you hum this will kill it . JD