Dedicated Circuits - Subpanel importance?

@djones51 Can you PM these potential violations or post them here? 

@All - Based on your responses the subpanel would reside right next to the main panel, so I do not see any advantages vs a pair of 20A breakers in the main panel. There is plenty of room. This simplifies things and I will look into a permit and inspection. Thank you.

The backstory here, which I may have mentioned in another thread, is that I learned "the hard way" of how important a dedicated line may be. My system was sounding pretty good, but I was listening alone during the day and at night. My brother visited twice and loved what he heard. My point - my system was the only thing using electricity during these times, something I didn’t realized until last Thanksgiving when we had a houseful of guests (as did the neighbors) and my brother said to everyone "you have to hear xxxx’s system". Practically every light, television, Christmas lights and tree were on at the time and a number of us headed down. The SQ was atrocious. Embarrassing! My brother walked out blaming my gear and exclaiming "what a waste of money"... A total disaster I want to avoid or greatly mitigate in my next system.

@artemus_5  I started the online permit application and it accounts for homeowner work. I stopped filling-out the form and booked a few quote calls with local electricians. I know what it will cost me to do the work and I will contrast it to a few quotes. I did get one quote for a single run in December of $800 that did not include mention of materials used. I know I can do it for less and why I've considered it. 

@oldhvymec Any chance you live in MA? :)

It is legal here as well.

My plan before starting this thread was to purchase 10,2 romex and run it through wall-mounted conduit to an audio grade outlet. I would use a 20A breaker matching the rest in the system as you should. 

I think MC is the one who suggested metal-clad 10,2 because the metal casing would reduce interference, noise or other...? I hoped to drill into this more to see if I should entertain it..

I think the only benefit of a subpanel is if the main can be split. This way you are not subjected to the noise of a shared common / grounding bus with the rest of the house. In fact, it is no longer a subpanel in this configuration. However, I would NEVER entertain splitting a main line. 

I have 3 electricians calling me tomorrow. Looks like they are video calls where I can walk them through my ask. I will follow-up here with the result. Hopefully others can learn from whatever comes to pass. Appreciate all of the input!

Thank you, everyone for the humor and solid advice. I literally chose to spend my time posting here today instead of running to home depot with my shopping list. Thankful I did. Eager to speak with the three local electricians tomorrow.

It's because I caught the audiophile bug that I am looking to save pennies everywhere I can, but maybe this isn't the place to save despite my experience. 

Great feedback as I had hoped! I will be PM'img a few of you, hopefully soon. One electrician wanted $100 just to give an estimate. Nope. The other two were in the same ballpark, which is like fives times the cost of materials alone. They were in sync as well with what they would do, which is run a line to s small subpanel in the listening room with x number of lines (equal in-phase) to x outlets. The breaker for the subpanel would be at the top of the stack in the main panel, with other breakers moved to the other bus if they have noisy end points like dimmer switches, appliances, etc. i now really want to do this myself because there is nothing complicated about it. Going to take the week to think it through. Thanks again.