Arrange circuit breakers in panel

           I've been following the discussions on this forum for many years, first time I've posed a question. I am in the process of adding two more dedicated lines to my rig. I was wondering, has there been a consensus on the best location, within the main service panel, of the placement of the audio/video breakers? I realize load balancing will dictate space used, but I've read that folks will place double pole breakers at the top of panel (in my case Square D QO 200 amp main panel) and some prefer single pole breakers toward the top. Has anyone experimented, come up with a better arrangement of the breakers? As long as I have the panel open, thought I might try to squeak a little more SQ out of the rig. Thanks.
If anyone has a more extensively tweaked panel than mine I would like to see it. The panel was taken down to the bus bars, cleaned, treated and reassembled. The entire panel, every contact surface is treated with Total Contact. There's a Gate, Mats, and more. Yet even I am not nuts enough to mess around with what you are asking. That is so far down the list of things that would be audible improvement it literally is not even on the list!
get your ugly loads ( motors, switch mode stuff ) on the opposite leg of those two dedicated lines.
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i forgot to add clean and tight and the highest quality breakers you can find, put your panel on a maintenance schedule as heat and load cycles can loosen connections. ( and in my case close proximity to salt water and therefore salt fog )

Heavy - good to see you weigh in also, hello to Rabbit and the pup.
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@ditusa ,
+1. Jea48 is my go to guy/person when it comes to electrical issues.
Second only to the late Almarg.
Hi       Just got in. Thanks for all the responses. Yeah, I've pretty much got the initial dedicated lines tweaked out,10 gauge wire, audio circuits on same leg, noise producing breakers on opposite leg, added ground rods all bonded to main. Like I said, I was just kinda curious if anybody had played around with breaker position in the panel. Was hoping the great and powerful Jea48 would have kicked in an idea. Maybe on the flip.

Thanks again
The back plane on modern breaker panels is ENORMOUS. You will never measure a voltage or noise difference between the first and last breaker on a leg.

IMHO, If you want the absolute best, lowest sagging lowest noise solution run a 220V line to your listening room with balanced step down transformers.

You can run 8 gauge or bigger cables with the lowest possible current, while the transformer in the room will provide the best noise filtering and ensure DC cannot get to your gear from the pole all the way to your equipment.

IMHO, I would run a 10/AWG BX/MC cable with solid copper core conductors from the breaker panel to a metal receptacle box. The metal sheathing on the BX/MC cable absorbs the (EF)) electric fields emitted by the wires and shunts it to ground. Now from panel to plug is shielded. The upside is low line noise and reduced antenna effect on AC power lines/branch circuits.
Downside BX/MC cable is pricier. I would run at least two dedicated 20 amp lines for audio. I have four in my audio rig. All four dedicated audio circuits are 250 volts 20 amps. With no noise or ground loops. Also, all four dedicated audio circuits are at the top of the breaker panel numbers 1-8. See the link below. Hope that helps. Mike                                                                                                              
   Thanks for reply. I've already run Diamond 10/3 w/o ground I found in a small hardware store. I believe the spiral configuration is all the noise rejection I'll need, since I live in the sticks. Was more interested in the mapping out of the A/V breakers, whether their position in the panel, either top, close to entrance feed lines, or down towards bottom away from household double pole breakers might help in noise rejection. 
I just bought a Square D 100amp. It has six spaces to mount one main breaker and five double- or ten single-pole ones.
I would recommend making sure your "audio/video" breakers are definitely on the same pole.  In most standard US panels, the poles alternate on each sequential breaker position.  So you would have to "skip" a breaker location in between each audio/video breaker so that it's placed on the same leg/pole. 

A normal US 220V breaker takes two breaker slots/connections and uses both 110V poles in a push/pull configuration to produce the 220V.