@bigtwin
It will depend on your equipment and which 12 cables you compare.
If you have high quality components, you are comparing high quality interconnects and you know your system well… like have listened to it for a thousand hours without change. Then a couple tunes will be enough to identify significant changes. If otherwise… maybe not.
There are levels of sonic changes in high end systems. The first question is: is this a high end system. These are like scientific instruments… they reveal very small changes. Then there is what you are testing… are they significantly different? Today I swapped a fake Nordost Odin 2 interconnect for my genuine Transparent Ultra XLR interconnect. Wow, the fake Odin 2 sounded terrible! Harsh, restricted sound stage, dynamics… it stayed in my system for about 2 minutes.
You have to consider swapping interconnects or cables as a complex scientific experiment. Typically, if I know my system well and the interconnects are fairly close on price… I will allow a week of listening to each. If you know your system well, compare vastly different performance / value interconnects… then part of a tune is plenty to make a decision.