How do I choose between Wide and Narrow mode for my Beolab 8?

Select the product in the Bang & Olufsen app, and switch manually between Wide and Narrow using the buttons in the top.

A specific beam-width can also be assigned to a sound mode. 

Narrow mode is optimised for active listening, where the listener is placed in the exact sweet spot which is centred between the two speakers and with the speaker drivers at ear height.

Use Wide mode for when you are not placed at the centre of the two speakers, when more people are listening, or when you are listening more passively, e.g. casually listening to music from different places around the room.