That's what carpet dealers call it (Transition). It's a wooden, metal or rubberized partition (molding like)a little curved in the middle to cover the endings of a carpeted floor,ceramic floor or linoleoum. There is plenty of room in the middle to get your wire thru.

If for any reasons you don't have a transition were you need it, install one so will allow you to bring your speaker wires accross the carpet. Also the transition doesn't have to be that wide, because you will be running only one speaker wire along side each wall for the 2 speakers in the back.

On the other side of the transition start pushing the carpet down underneath the molding with a large flat screwdriver and use a hammer if necessary to make enough room for tucking the speaker wire in there.

Beleive me it's very easy to do, and when you reach beyond a sofa you don't have to be to fussy with it, nobody sees the wire there.

The 2 microphone stands cost around $ 25 each at any large musical instrument supplier including the large base. You will need to buy also 2 little L shaped brackets (3 inches)long total lenght and drill a larger holes at on end of the bracket in order to be able to mount it onto the threaded top section of the pipe and fasten it with a washer and nut. The other side of the L shaped bracket will screw right onto the bottom of the speaker.
Hope I expressed myself clearly enough, wish things work out for you.
J. Bond