The RCA part of the lead is a well shielded 75 ohm cable. The range of RF frequencies on that wire is high, so this lead should be good quality, good shielding from DC up to at least 40MHz.

The 5 way connector is not MIDI compatible. Use a screwdriver to open the connector and make a note of the connections used. The link to the metal shell of the connector is important.

Also be aware that the M lead (between your master speaker and your processor/player)has different plugs at each end, whereas the S lead (between the speakers) can go either way.

It shouldn't be too much of a challenge- just be gentle when you're opening connectors and putting them back together again.

Simon.