I used to power my W15’s with a Crown. If you are running stereo W15’s then it is the same as any other amp - reds to (+) and blacks to (-).

If you are bridging to one W15 then you will use both red terminals on the amp and run one to the W15 (+) and the other to W15 (-), then go into the amp menu and set it to Bridge mode. Try swapping connections on the speaker, meaning try both in-phase and out of phase to see which sounds better for your W15 placement in relation to your primary speakers.