Cryongenically treated in-wall AC power wire

 I tried to cryo one of my DIY power cables to see what happens to the sound.
After burning-in, I opted out of cryo treating my reference cables.
It made the sound more lean and dry, less full.
One more note - I found that the longer the power cable is, the more of its "sound" is present in the system. That can be good or bad.
If you have very fast-detailed-silver sounding power cable, 1 meter will influence the sound in that way more than 0.5 m of it.
I would bet that the same applies for the power line in the wall.
I have dedicated power lines in my system (8), and they are on a separate breaker box.
So my apartment has 2 breaker boxes - 1 audio and 1 for everything else.
I kept the wires at minimum required length, which is still several meters.
Each line has electric filter installed before the outlet.

I think the investment in AC pays off in the final sound.

Not to mention the directionality of the power cord. That’s why Audioquest controls directionality for their power cords, as well as all of their other cables. So unless you can verify which direction the wire in the DIY power cord is supposed to go, cryo might not make any difference or may allow you to hear how the wrong direction affects the sound. There’s also the issue of thermal shock when cryoing cables that means judgements should be postponed at least a week after getting the cables back from the lab.

I'm going to take it one step farther. When I installed my dedicated 10/2 wiring for my audio room I took the time to listen to music by auditioning the 10/2 wire attached to the circuit breaker and AC outlet from both directions before the wire was cut and run in the walls etc. One direction sounded more open than the direction. Yes, it was a major pain to do but I was 25 years younger.

Here’s simple info.
For wire, find and buy top quality “fanatically shielded” specialty 10 ga used for the most sensitive commercial applications; super critical robotics for example. 
For ground information go to the Equitech website. The man behind Equitech’s patents, Martin Glasband, has created products that have solved more ac power noise problems than “all” the other electrical engineers on earth! Mr Glasband is a real expert; has authored sections of the US Electrical Code. He has helped many personally. 
Also, the most important factors in your new wire are 
1. Shielding
2. Termination
3. Placement in your walls.
4. I would use at least 3 separate runs which gives you great flexibility for experimentation in the future. 
With quality cable don’t give a thought for a few feet here or there. Irrelevant. However, make sure you have enough that in each run the wire is relaxed; do not install it ‘tight’. 
Be aware that there’s an endless amount of “voodoo” and utter “nonsense” from some “fools” in this forum. They are not well meaning; just plain ignorant, stupid, or both. 
Also, if/when it’s affordable an Equitech 2Q or 3Q will improve your sound “ dramatically”. Best wishes. Pete

Draw out your new room and equipment locations precisely to scale. Consider all equipment you may want. It’s an important project. By all means have a normal compliment of wiring regardless of your hi fi demands! Seriously consider wiring through metal tubing suitable for underground use. This will also facilitate install and allow future upgrade.