Do these really make that much of a difference? I have all my equipment, mixer, preamps, and soundcard hooked up with some rca cables that I had lying around from dvd, tv purchases. IS this a bad thing?
They will be fine. The big problem with cheap RCA cables is reliability. They will work until they don't, then throw them away. In a home studio situation, they will likely last quite awhile.
Cables make a difference. A nice and cheap option is to pick up a pair from bayoucables.com, ca. $15 for a pair, a little more if you need lengthy ones.
They have canare cable and good connectors. I use a 2m instrument cable of theirs for my electric guitar. Good clean signal, better than generic "low noise professional bla-bla" ones, branded as if you were supposed to expect noise from a short cable in the first place. Poor soldering and connectors make them unstable quickly too.
You could also make your own cables pretty easily: here's how.
And keep your cable runs short and balanced if you can. Silver cable from homegrownaudio.com seems to be medicine for harsh treble,
but it's a little expensive at ca. $5 - 8 for the three conductor cables per foot, but not much compared to b.l.u.e. and monster cable.
