Some gear will be affected much more than others. The magnitude of difference a cable makes is largely dependent on what it is connectd to. It makes little sense to speak of cables without the specific equipment. Cables are passive. Ideally they should have no affect. In the real world, they may or may not make a difference, depending on the type, design and choice of equipment.
A New Believer
I have listened to many systems over the years, and have never appreciated the difference speaker cables can make to a sound. In fact, I was so skeptical of the sound changes they can make that I have always not bothered with any special type of cables, generally going for generic (and dare I say it) roughly made ANY copper wire plugged in to amp and speaker. Well, imagine my surprise when I decided to do a blind test and listen to what difference cabling can make. Wow, my Vand 3A Sig's had been getting strangled! (some of you guys may want to strangle me if I told you what connects I had been using). So I am now a firm believer, cables DO make a difference.