What do audiophiles want from a cable?

Yes terry9, in some cases a cable will sound just fine.  You would never know what you were missing.

I think some cables do act as filters, but not in the sense that most think.  The cable is not filtering thru the audio signal, but filtering OUT all of the crap that is detrimental.  Mainly stuff that comes in on the a/c line that keeps the equipment from optimal performance.  I'm a fan of what ferox has done for my system as well as the Bybee products.  

I pick cables to get the best out of and not restrict the full potential of my components.To me its all about a balanced system.I run all Furutech which are better then out of the box cables .

Cables essentially are tone controls. You are basically altering the lows, mids, and highs by trial and error. It just comes down to which one floats your boat in your room with your setup.

Waxwaves, you use Purist cables, all Ferox. Have you ever tried Purist fluid cables? Now when it comes to Purist it's a fun game, there used to be fluid and Ferox cables with both Ag/Cu/Au alloy conductors, that's, mostly silver, and Cu/Ag/Au alloy, that's, mostly copper. The newest Luminist revision has no Ag/Cu/Au with fluid combination.
I have original Colossus fluid speaker cables, Neptune Luminist Single Crystal Copper fluid RCAs, original Colossus Ferox RCAs, used to be fluid that I bought with Ferox, and original Maximus Ferox RCAs that used to be fluid in my set-up. Fluid and Ferox have their strengths, the analogy could be that fluid Purist, especially all copper, sounds like a tube amp, and Ferox like hybrid/warmer transistor. The Neptune that I recently got has an incredible deep and layered soundstage that I doubt  any other Purist cable could match, and also exquisite slightly rounded highs. Other things being equal, Ferox may be a little quiter with tighter bass. So, no wonder that a number of people use both fluid and Ferox cables in their systems. Some would call it sound manipulation, yet others would call it fine tuning. I would not run all Ferox cables in my system but I could run all fluid cables, provided I had Ag/Cu/Au speaker cables. Single Crystal Silver with Ferox might give the ultimate resolution speed and bass and balance with great soundstage but it costs a fortune.

I also tend to see the system in a holistic angel like renolds 853 and waxwaves. Overall i see the software, hardware, the room and finaly ouer body ( mostly the ears) as all connected to the expirience. I too have expirienced a cable the has huge synergi in one system and very little in another. When i alter a component in the system, it creates a domino effect so some of the other components in the system again can be optimised. Getting better a better and better system makes the diffrences when changeing anything more and more audibel. I whish that i could find a cheap cable that did it all right but i have never found it yet.
At a certain level i didnt need the filtercabels that takes out nasty things. Before that i hadent been dealing so much with the room, decoupling and the electric supply. For me cabels are components, i have never heard a highperformance SOTA system without superb expensive cabels. I tend to think that the powercabels today is the most importaint cable in my system and in the low level time it was the most unimportaint.

My cables, as well as the rest, shall improve the realism, make it more involving and letting me feel more when i listen to the music. I think most will go for that but how much you are willing to offer on them.
Here i am looking for the lowers fruits first and i get a lot of help form other expirienced audiophiles. When i think i have reached a homogenic level in the whole chain, i usually start lifting one component up the ladder again and then the rest follows over the years. Which component it is, depends on many things but feeling that making a good deal, eg superb price/performance matters a lot. 
Trying new super cabels in my system is a easy way to learn more of the capacity/potential in my system, that may be hidden for me. Unluckily i dont have so many opotunities to do it,as supercabels are rare in this area. Maybee we could swift cabels with each other once in a while.
Good lisining.