Does creating a loom in cables in a system make a significant difference?

using cables from the same company makes more sense but if you're going to use any kind of cables get OCC single Crystal because it is far superior than anything ofc on the market at any price, but there's also cheaper and higher-end OCC single crystal wire as well so as you go up in price things get better and better but OCC single crystal is the best wire for audio and it has been proven for over 50 years to be the best.

While I respect the views of those who through personal and in some cases very long positive experience with a cable loom, my ears will probably never discern a difference among high quality elements from different companies. I don't have the Golden Ear ability to distinguish between the subtle differences in SQ described by equipment reviewers and members of this forum.  When I was at Axpona in April at a Nordost exhibit, the rep there put me down for not having a Nordost loom. My system sounds great nevertheless with mix and match.  I am able to distinguish some differences in cables. I started out with inexpensive Cullen IC and digital Cables (heavy gauge copper) but I sensed a "blanket" over the music compared to my older Kimber cables. My speaker cables were Nordost Blue Heaven, (upgraded to Tyr 2) in both cases.  My outlets are 20 amp and my conditioner and power cables are Shunyata.  I then switched to Synergistic silver and the difference to me was dramatic (and no harshness as some have warned).  But posting the question was my own reality check.

I always thought a wire loom was a way to keep your wires neat and tidy, regardless of brand. 

I've messed with "high end" cables since the late '80s. Yeah, you can hear a difference. Maybe you shouldn't- that is, the cable is coloring the sound. I dunno. 

One serious guy I know swears by basic old stock Rat Shack and his system is beyond the pale.

I think the one advantage of a "full loom" is that it enables you to hear the "house sound" of that brand/line. Cabling can be tricky if you are trying to use it to compensate. I use very basic stuff in my vintage system- trying to stay close to period. In my main system, I had great success with Kubala-Sosna, which nicely matches the character of my system. But, I can't extrapolate. I will say K-S stepped up when a very long XLR had a bad connector- 17 years later. He replaced it at no cost and no cost shipping back. 

If you do indulge in cable comparisons, you can get a headache. There are some known synergies for people with certain speaker/amp combos. I would start there if that's a question. 

I'd also say, with some experience, that I would rank the importance of cabling low on the priority list if you are building an entire system from scratch. The cables can make a difference but I wouldn't put cart before horse (or something). 

I say if you have crappy cables it's important to have ALL crappy cables for consistency. Also, if you decide otherwise, it's important to use a forum like this to note how you've bought expensive cables and like to be recognized for the serious listener and real smart person you obviously are. Otherwise, what's the point?