It funny to read all those comments about the issue. Especially on A'gon. Come on its not a HomeCinema forum!
When I was picking speaker cables for my system, I also experiemented with different lenghts.. there was a PROFOUND difference between 4m biwire pair and 2.5m biwire pair (both cables Nordost Solar Winds, exeptional, but discontinued cable). With shorter cable I heard much more information, I was feeling like driving a stiff sports car (feeling the road, all the bumps and turns), while longer cable gave me the comfortable sedan-highway cruise-feeling. Interesting things happened with 8m Nordost Solar winds. This kind of lenght made very, very smooth high freq, more bloomy voices, etc.
Also there are differences in interconnection cables leghts. But I choose to practical side: if I need 1m cable between third and first hif rack floor, I looking at that kind of length and do not think about 0,5m or shorter, or how do they might sound...
I think I could pass blind test with speakers cable legths.. and pin pont which is connected 10/10, BECAUSE there is actually, easy to hear difference. And you do not need $100.000 rig. And forget physics and science here - you do not know some Xs, that is why the formula and outcome you think is right is actually wrong.