Absolutely would like to resolve it.
Thanks
Do some simple tests first to establish the nature of the issue; which could be a fault; an ground loop; or the cable shielding not being that good (regardless of price and the bollix that the manufacturer/retailer claims)
First thing, test for a ground loop (earthing issue) by powering the sub from the same mains sockets as the amp. Try this with your existing subwoofer signal cable and a substitute.If there's no hum with either, then it could be a difference in the earth levels between the mains sockets for the amp and for.the sub''s main home. Solution: buy a ground loop isolator.
If the hum comes back with your existing sub cable, then the shielding isn't good enough. LMK and I'llpoint you in the direction of a sub lead that will kill the external interference.
Where there's still hum in all circumstances, and you get this with the sub'svolume on the 50% setting on the sub's volume control, then have a word with the retailer.