Do cables really need "breaking in"?

More likely it was invented by cable purveyors, who wanted to discourage returns. "Don't like it? Let it break in some more." I've never heard of a properly controlled comparison of old and new cables, though you can expect lots of personal testimonials to follow.

Given that there is no permanent physical or chemical change to cables resulting from their use, the most likely explanation for any perceived change in sound over time is, as you say, psychological. And your final point is a good one, too: There are too many confounding variables to draw any conclusions about how a cable's sound changes over time, even if it does. But that never stopped anybody.

It is possible to argue that the properties of the dielectric change with increased use. I don't know whether this is audible. Given that audiophiles can hear the difference between different cables, it isn't inconceivable that break in could be audible. Audibility can manifest in a variety of ways.

People hear things in different ways. I always used to listen for frequency response effects when switching components -- cleaner highs, tighter bass, smoother mids, etc. My first experience hearing a cable change was a little startling. I had a high quality recording of a jazz trio that I knew well. With the music playing in my family room, I could imagine the trio in the family room when I was in the adjacent kitchen. But when I walked into the family room, I could tell they weren't there live. After I upgraded my speaker cables, I couldn't hear any frequency response differences, but this recording now provided a "same room live" illusion -- if I closed my eyes, I could imagine them in the room with me! I've been a believer in quality cables ever since.

Some discussion of cable break in from an engineering point of view is provided in Audioquest's cable theory treatise at www.audioquest.com. Check out Cable Theory page 5. Happy listening!

interconnects are the most sensitive to breakin & can take several hundred hours, speaker cable not quite as long. You won't believe any of this until you hear it yourself though. I once tried to return some expensive ic's but the dealer talked me into waiting a month & I'm so glad that he did. AC cords don't seem to change much that I've noticed, but others report differently & who am I to argue?

Matt, cables do need to break in, for about 10 seconds. Consider, if cables need to burn in, what changes? And if you say they sound fine after, say 50 hours, do they stop changing by some miracle or do they keep burning out?

For those who believe in DBX tests, there have been none, zero, to prove that wires benefit from any sort of burn in. For those who prefer anecdotes, many of us have never noticed a change in a cable from brand new to broken in. Many say they have. This is one cable dispute to which I think there is an answer. You simply have to decide which group is delusional, the group that thinks nothing's changed or the group that thinks something happened.

This burn in argument offered by retailers of cables is the best argument I know of for the proposition that cables sound different from one another. If they all sounded alike, none of them would have anything objectionable about their sound to get used to during the "break-in" period.

Having an old EE degree, I thought this made no sense. However, I have noticed that cables do sound better after they have sat in one place for many hours. One article suggested that the crystaline structure is under stress when bent and that after playing for many hours, the cables "relax". Try it, you'll like it.