W371 calculates how to integrate to 8361s based on the measurements of 8361. In other words, it calculates how to set the correct crossover frequency to 8361s etc based on your room, treatment and how you placed the speakers on them.
Place 8361s horizontally if your room is very small as this will attenuate the mid/high bass radiated to side walls. Place them vertically if your room is fine.
Yes. I never turn off my 8361s.
They are different. W371 improves clarity from 60hz up to 500hz~ because it enables speakers to interact wth the walls/room less. 7380 is just a large big subwoofer.
If you want to know how W371 does that: W371 cancels the sounds around the speaker and at the back of the speaker to make them interact with the walls around them less.
@Blockader - Thank you for those useful clarifications, much appreciated. Do you think a pair of the 8361A/W371 combo would be enough or ideal for a superb music listening experience in a home?
In one of the case studies on the Genelec site, an audiophile has done exactly that but now I understand why he added a 7380 to the mix. The job of the 7380 would the be to address the lows, for instance from 20 to 60Hz. Not sure if this is really necessary as the W371 go down to about 25Hz or 30Hz. Is there a PEQ facility within GLM, particularly for the lower 2 octaves?