I was recently in the process of building a second system where I had the need for either:
1) 3 ft interconnects, 17 ft speaker cables
2) 17 ft interconnects, 9 ft speaker cables
When I did the research, I found that there are divided opinions on this subject. I understand that long interconnects are more subject to picking up noise from other sources, but that was not a factor in my case. Amplifier power was also not a factor.
The problem is that custom lengths of either interconnect or speaker wire are very expensive. Many manufacturers won't even do full refunding (or for some, no refund at all) of custom lengths. Others do not even make custom lengths. So, it can be very expensive to experiment.
I was really surprised that this is such a debate. It seems that the rule should be more or less a hard and fast one (Although I don't no why. It seems nothing ever is).
I know what ending up being my findings, but I do not want to bias any response.
I'm really curious in hearing the opinions/experience of others....