Can anyone explain cable risers?

Cable risers are for those are seeking "street cred" from their audiophool friends. You can bet your bottom dollar that NONE of the various recording/mixing/mastering facilities are suspending their cables during the making of a recording.

Nor do they place bags of rocks or crystals on their interconnects, speakers and such.

If folks would spend more time and effort acquiring the very best source materials to playback and fixing the response anomalies found in their listening room, they would be rewarded handosmely with a much better sounding system...

-RW-

Not something i worry about but some carpets are prone to static electricity which can only be bad.

Also, running wires parallel to each other and in close proximity over a distance is generally not a good idea due to em field interaction and risers are one way to avoid that.

YES but the best explanation will come from your friendly neighborhood voodoo doctor.