I'd be careful. Cryo freezing can potentially damage the non metal part of your cables sucha s teflon and PE shileds, spcers, etc. As for the effect on metals, it will depend highly on the specific metal and metal alloy used. Unless you (or whoever does the treatment for you) has access to the phase diagram for the specific alloz your cables are made of, this can be a totally random process which could even hurt. While it is true that treating metals at very low temperatures can lead to a more crystalline structure, the temperature does not necessarily have to be in the "cryo" range, and the biggest factor is time. What you are trying to do is ensure that as much of the metal is present in its crystalline (vs. amorphous) state at its temperature of use (the usual "room temperature"). With pure metals, this is pretty straight forward, since you can look up published pahse diagrams, look up the transition temperature from the amprphous to the crystalline state and "anneal" you metal at that temperature for a sufficiently long period of time, then bring it to room temperature with a warming (or cooling) regime that avoid destruction of the crystalline state.Evne with a pure metal, this is not strightforwad (just look at the many possible structures of any pure metal in a phase diagram depdning on its temperature treatment history!). With an allow, this is even tougher, since if you get the temperature treatment "wrong" you can even end up with phase separations (where the minor components of the alloy spearate into pure micordomains and break up the continuity of the alloy). This is basic materials science/metallurgy. I do not claim to know what the effect would be on the SOUND, but before you pay major ucks to have this done to your cbales, best be aware that it is NOT strightforward. If you want to know more, drop me a private e-mail. Though this is not my field of secialization, I know a little bit more about it than I can cover in this post.
Cryo your cables?
I was talking with a buddy of mine that builds racing engines for karts and the subject of cryogenic freezing came up. For the past couple of years this has been THE hot thing to have done to your engine parts to reduce wear and friction. I checked out a place on the web called 300below.com that does this work. Now for the interseting part relating to cables. They say that one of the frequently treated alloys is copper, espescially welding electrodes. Quote- "The increased durability of Copper from cryogenic treatments is increased homogeneity of the crystal structure. The material becomes more compact, dissolving gaps and discolorations or, for example, chrome carbides found in class II copper. Because of structural compactness there is less electron obstruction which improves electrical conductivity. It has also been learned that as a result of increased conductivity, welding amperage can be reduced thereby further prolonging the service life of electrodes." This got me thinking, what would such a difference in crystal structure do to interconnects and speaker cables? It would seem that what they claim of reduced electron obstruction and increased conductivity would be a positive thing in an audio environment. Has anyone ever thought about this before or actually had their cables treated? I would like some other opinions on this. I'm definitely having my drag-bike engine shipped out this winter to be treated, but I never thought before about how it might make cables sound different.