And since this misunderstanding is far more common than I thought, the EXPLANATION.
Speaker cable is traditionally two conducters run in individual plastic sheathing, usually either different colors or marked with a stripe on one conductor and plain on the other, so correct polarity can be ensured.
In the posher verions of this, you may well find the two inner cores are then encased in one thicker outer plastic sheath.
Now the crucial difference between cable for connecting passive loudspeakers to an amplifier and cable for connecting active loudspeakers to your mixer or other output from your recording system is....
One carries AMPLIFIED signal with a lot more oomph all ready to feed your passive loudspeaker and because the signal IS so powerful, it has less need to be shielded from external interference.
The other carries low level LINE signal which is amplified by the internal amplifier in your active loudspeaker and IS sensitive to external interference.
So really what it comes down to is that, regardless of whether you use balanced or unbalanced cable to feed your active monitors, you are well advised to use a SCREENED cable.
This is where one connecting wire is sheathed in plastic as per the conventional speaker wire, but then the OTHER conductor is wrapped or braided round the outside of the first conductor to form a shield against electronic interference from external sources.
In this case, the hot or phase signal should be applied to the inner core and the neutral or `negative phase` of the signal applied to the outer wrapped conductor.
In a balanced shieded system, there are two wires insulated from each other but both wrapped or braided in the outer metal sheath. In this instance, one of the inner cables gets connected to the +phase or hot and the other to the neutral or negative phase, whilst the wrapped or braided shield is connected to ground.
And this is realistically the best of all worlds.
I am really hoping this is understandable to all.
What it boils down to is for passive speakers you need two-wire cable with good sized conductors (NOT bell wire!) and for active speakers you need either proper trs or xlr balanced, screened cables with a shield PLUS two inner conductors, or at the very least single core screened cable such as is used for guitar cables.
So. If the amplifier is built into your speakers (does it have a volume control?) you need balanced mic or unbalanced guitar leads.
I use a pair of HS80m speakers with two XLR to TRS cables because my monitor controller (passive volume control between my soundcard and the monitors) only has TRS.
But I also have a pair of Tannoy passives which run from a Quad power amp, connected with 2.5 mm squ. cable.
And of course the signal from my soundcard to the Quad amp is passed with regular screened hifi style cables for left and right.
Phew! Any questions, just ask.