Time for dedicated outlets!

I would like some advice on what exactly to tell my electrician to be sure I get what I need. Is just saying that I want two separate dedicated lines to the listening room sufficient or are there other key fraises that should be included in my description of the work I would like done?
I grounded the sub-panel separate from the main panel using a grounding plate buried outside connected with 6-gauge grounding wire
That's a violation of the NEC and potentially hazardous. All grounds must be bonded together at the service panel, without exception.

The highest quality ground is a low impedance ground, and that's the ground provided by your utility. If there's an issue with your utility's ground, it's their responsibility to correct it.
Cleeds, that is true. If the run is 50 feet or more you should use # 10. If 100 ft  go to # 8.
10-3 was used for greater distance. My nextdoor neighbor who is a electrician ran that. So I have 2 20amp. At the wall we put 2 sets of outlets each set is on a separate breaker

Outlet. Outlet. Outlet Outlet
Outlet. Outley. Outlet Outlet
     1.          2.         1.        2
Breaker Breaker Breaker Breaker

It is this way so I can decide how much load is on each beaker.
Why are you guys using 10/3 Romex? What are you doing with the extra wire? 10/2 Romex has 2 insulated conductors and a bare ground. 10/3 has 3 insulated conductors and a bare ground.  Maybe you guys are confused about the wire naming? If not, I'm so curious what that extra wire is for!
Baddoge, if u have four breakers u have four circuits and u did not get that with 10/3 wire. 10/3 wire has 2 hots a neutral and a ground and is good only for 2 circuits. You must have run more wire