Difference between RCA & audio coaxial cables?
"Is there any difference between a regular RCA connection audio cable (like the stereo red/white ones) and the ones you use for digital coaxial audio connections?"
Video cables and coaxial-digital cables must be made with 75 ohm coax.
Audio RCA cables can be made with any of the popular coax like 50, 75, 110, 300. As long as the L/R are the same, the lower speed audio signals dont care about the impedance.
The SPDIF was designed around using a video cable with 75 ohms impedance for the coaxial-digital connection.
A normal RCA cable works great for subwoofers.
But sometimes you get hum with an ordinary cable. This is because the subwoofer has an amplifier and the AV Receiver has an amplifier. A normal RCA cable ties the signal ground from these 2 together. The two amps 'fight' over who is the source of 0.000 volts and this is called a 'ground loop'.
A "subwoofer cable" with little arrows is really a broken RCA cable. The shield is not connected at one end. This keeps the two amplifiers from seeing each others ground and solves the ground loop problem.
"if I buy the specialized cables will I notice a sound enhancement?"
But does the 5.1 sound drop out every few minutes? People have used an audio RCA cable for the coaxial-digital connection and it appears to work. But they noticed the sound skips/drops out every so often. Using a proper 75 ohm video cable solved the problem.