Sadly, cable "break in" is real. You don't have to understand WHY to know that the phenomenon is real. I use 50 conductor flat computer cables (remember the old hard drive cables ? - only with 50 silver plated copper wires) for speaker cables. They "break in" in about two hours. In the first half hour, the sound changes radically; it is a wonder to hear. At first, it seems that the two speakers they feed are connected out of phase. I was sure I had done something wrong. I shut down the system and checked out my connections. They were fine. I turned everything back on and continued listening. An amazing swirl of audio shifts occurred for quite a while. The worst was over in 30 minutes or so and in the next 90 minutes the sound got smoother and smoother. A friend is using a set of these cables on his Martin-Logan electrostats (McIntosh power amps) and says they are the best he's heard. I use TV coax for some interconnects and 300 ohm twinlead for some other low impedance interconnects and the "between components" cables don't change much in time. A certain company claims that their wires need 600 hours of "break in." Long enough that the "you can send them back for a full refund" period is over. USB cables have proven to be critical and I don't try to make them. The best I've found are Zavfino's from Canada (when used between a laptop and PreBox S2 Digital). DACs seem to be very fussy about their cables and what works well for one may not suit a different DAC. Happy Listening!