I have read it is better to use ceramic electrical insulators (isolators)and keep speaker wire something like 4" away from any material, to avoid electical effects.
To do that, I have to send the wire up to the ceiling, across the room, and down to the speaker. It's pretty easy to do and keeps the wire off the floor, although it will look strange. This is a 6 speaker HT system.
However, it adds 50% more length to the cables, some of which are already long (9 meters).
The question is whether the extra length will degrade the signal more than just laying the cable on the wood floor.
thanks,
LesHalles