Do I need 10 gauge power cord if I have 10 gauge from panel?

8th-note

Watt meter is nice but it doesn't in my view accomplish everything you want.

Not sure it measures the extremely high speed changes in Power fluctuations needed for Music.  
Isn't the benefit of larger gauge wires throughout the electrical food chain to avoid any unnecessary impedance when power demands occur?? As tiny and subtle as they may be for all those gentle nuances in sonic transmissions.

@fsonicsmith1 Bad AC perhaps?  The one thing that nothing but an AC Regenerator or top notch power conditioner can help with. This is especially important to consider if you live in a high density population area or are near a commercial zone “dirty” AC  can be a very real problem. 

@jasonbourne52 … “It is unlikely a 14 gauge power cord is not negatively impacting the sound." That is poor grammar!”

You are correct. I have no idea what I was thinking: It is very likely a 14 gauge power cord is negatively impacting your sound quality. 

No.  Listen to JasonB

@jasonbourne52 … “Do you really believe that you can hear a difference between the Hurricane vs. the Thunder? A degreed electrical engineer will tell you otherwise! ”

I can hear the difference between a 1 meter and 2 meter Hurricane… as well as all the other power cords I own.

I came up with my own sonic rating scale years ago, but more recently found this one. It helps to systematically evaluate sound quality changes.

Also, you cannot honestly speak for all electrical engineers. I have know hundreds. I can say that most of those that actually sit down and listen to a good system will hear the difference… those just asked may say that is impossible.