PA1 - Speaker Connection

Got a SNOM PA-1, all registered etc no problem there , I also have a brand new Adastra AH-25 Speaker for it . the PA1 has the standard red/black 2 terminal outputs . The AH25 has a 4 wire cable labelled as Signal , +12V and 2x Grounds - any ideas how to wire this together ? I know the Speaker is effectively the same as a NR-24 KS by Monacor - any help would be appreciated!