I have two identical powered 12" subs, the quite budget friendly Chinese-made Monoprice 9723, operating in a 5.2 system via dual sub outputs of my Denon AVR.
This model gained some notoriety for having intrinsic hum issues out of box...on some units. Wirecutter tested two and found no hummers. In my case, one hums, the other doesn't. It's not the cables or the AVR or the position of the sub. I even packed up and returned the humming unit under warranty and was sent...another humming unit. At that point I chuckled and called it a day... it's very low level hum anyway and these subs will surely be swapped out for others evernutally. Until then, I'm curious to know --
-- what tends to be the cause of an intrinsic hum in a sub? (I presume it's 60Hz but haven't actually measured) . Grounding? Amplifier?
-- is it something a very modestly experienced soldering-iron/multimeter wielder like me could diagnose and fix without electrocuting himself? Accessing and removing the power amp plate is not a problem.
This model gained some notoriety for having intrinsic hum issues out of box...on some units. Wirecutter tested two and found no hummers. In my case, one hums, the other doesn't. It's not the cables or the AVR or the position of the sub. I even packed up and returned the humming unit under warranty and was sent...another humming unit. At that point I chuckled and called it a day... it's very low level hum anyway and these subs will surely be swapped out for others evernutally. Until then, I'm curious to know --
-- what tends to be the cause of an intrinsic hum in a sub? (I presume it's 60Hz but haven't actually measured) . Grounding? Amplifier?
-- is it something a very modestly experienced soldering-iron/multimeter wielder like me could diagnose and fix without electrocuting himself? Accessing and removing the power amp plate is not a problem.