The hiss with your ear next to the dome tweeters means they are working. Agree with Herman it's not a malfunction. Advise you not increase the volume above normal listening levels to listen only to the hiss.
You can lift ground by adding a two prong cheater to the end of a three prong plug. So long as one component is properly grounded all the others linked via interconnects will share that ground. That's why if you did have hum, which sounds like you do not, the hum will persist even if the offending units are turned off but remain connected.
Dissatisfaction with the system's sound indeed indicates distortion. Surely it has nothing to do with your operating dome tweeters.
Enjoy that pretty room you have but move the carpet over so it's centralized equally between your speakers.
You can lift ground by adding a two prong cheater to the end of a three prong plug. So long as one component is properly grounded all the others linked via interconnects will share that ground. That's why if you did have hum, which sounds like you do not, the hum will persist even if the offending units are turned off but remain connected.
Dissatisfaction with the system's sound indeed indicates distortion. Surely it has nothing to do with your operating dome tweeters.
Enjoy that pretty room you have but move the carpet over so it's centralized equally between your speakers.