was previously using my sub's high level inputs (speaker connections) to connect to my amp and recently switched to connecting my sub via its low level inputs using el cheapo rca cables...
Is this in a surround or stereo system?
If this is in a stereo system, I likely to stick to high level inputs so the sonic character coming out of the amp feeding my sonic channels is the same as the ones going to the subwoofer.
If this is in a surround system, I'd use the dedicated .1 channel out via RCA jacks.
can i also use decent component video cables for stereo (or 2x component vid cables for 6-channel analog audio)?
Possibly. Note though that video and digital cables have different design characteristics from analog interconnects. I've read that video/digital cables can be used for analog but not the other way around.
What's your objective? If it's to save cost, ask Hyperaudio to make you six runs of Ixos I/C using Pheonix connectors. Pretty decent cables for the money.