Ill tell you how they sound, once I have found that out myself
Put your fingers in the gap and pull downwards (toward the bottom of the speaker)....then each of those small circular holes above, open up to accept (thin) wire.
The sliding bits you pull down are spring loaded, so they clamp the wires when you let go.
(The metal that clamps is only thin - so ensure it clamps the bared conductor and not the insulation of the wires).
If you can see the polarity markings, fine, but they don't appear to be clearly marked to me.
If not, you can easily connect for
relative phase (so the two speakers are in phase with each other) by just connecting your red / black the same way round on each cabinet.
But ideally you want
absolute phase to also be correct - you don't want both drivers to be 'sucking' when they should be 'blowing'.....you want a positive pressure on the studio mics to be causing your drivers to move forward.
If there are no markings, get a
1.5 volt battery and look for an initial
forward mid/bass cone movement as you make a
1 second connection to it - then mark the terminal that was connected to battery positive with a
+