I am having an issue of both mechanical and electrical noise/hum emanating from my preamp. I can hear a slight noise/hum from the actual preamp unit as well as well as from only 1 of the drivers in each of my 2 RM40's. The noise/hum is only audible in the top most cone speaker.
I thought it might help the preamp manufacturer figure out what is wrong if I could give him the frequencies of this driver?
My RM40's are circa 2001/2002
Thanks