User Manual Pyle PDICS6 Home 6.5'' In-Wall / Ceiling Speaker System

No you cannot. These need to be connected to a receiver to power them and control the volume.

The speakers will need to be wired to a stereo. They really sound
good, especially for the price.

Yes they could be installed in a wall. There are 2 screw clamps that
go in behind the wall board that holds the mounting case in place,
then the speaker locks into the mounting case.

There are tabs that go up into the ceiling. When you screw them
down, then tighten up against the inside of the ceiling.

Its been a long time since I've used these speakers, The answer
would be no. The speaker's inner flange diameter and the
attached clamping mechanism would be too small to fit/seal
properly on a 9.5 in., hole. The best option is to properly patch
the 9.5 in., hole and cut a new hole (the size/diameter of the
inner flange) that the speaker's inner flange can properly fit into.

No. Just make a hole, connect the wires to the speakers, tight the
bolts to hold the speaker to the ceiling and put the cover on.

They are enclosed the way they look, the bottom portion is an
enclosed housing and the speaker snaps inside of it. Very easy
to install, just remove the speaker from the housing and secure
it to a rafter. Already has holes predrilled for mounting and for
passing the speaker wire through the back of the mount.