Burmester 877 MKII XLR pin polarity

The pinning is the following: XLR Pin1 = ground, Pin2 = neg, Pin3 = pos. This pinning is a standard pinning for Burmester units.
helle Koslekt1 , this info supplied by Burmester Germany

Another answer to your question about connection if the pins are iverted , no problem , you can 't damage anything .You can change the connection at the speakerbox
to have the proper phase , just try it to hear you notice any difference