Did a lot of reading and research but still not clear how to solve my optimal setup. Therefore starting this new tread and hoping on some expert knowlegde! Setup as it was in fully wired ML:

• BV7-55MKII  as videomaster in option 2 with 7.1 surround front BL 8000, back BL6000, side BL4500 and woofer BL2.
• BS9000 MKII sw 2.1 as audiomaster in option 0. Chromecast Audio as A.AUX input to be used as audiosource to all BV's.
• BLGW (Philips Hue, Remote acces subscription, IFTT).
• 2 BV'6-26 HDMI (kitchen and bedroom)
• All BV with Chromecast especially for video streaming.
• Bought a BLC with the BLGW for future use but was not using it

Last week I bought a Essence MKII to make my first steps in NL/Multiroom world. Together with the Essence I bought a second BLC. Simply started the installation:

1. by adding the BLC in the ML chain (parallel like the BLGW)
2. by linking the Essence to the BLC without speakers and without IR device
3. BLC setup as AudioMaster otherwise no audio distribution

in BLGW all new sources were found and added the BLC and the Essence as Network link products in the BLGW. Of cource this setup gave problems because the BS9000 is the destined AudioMaster: Radio, CD and A.MEM/A.AUX/N.Radio/N.Music still activated the BS9000. Simply turning of the BS9000 resolves this problem. Not nice as I still would like to use it (and not only as a peace of art). After doing research (thanks all for the great info!) I went for a second option:

1. BS9000 attached with ML to the BLC directly, therefore no direct connection with the rest of ML.
2. BLC linked to same network as the Essence.
3. BLC setup as A.SLAVE

Now the BS9000 can be started from the NL side (BEO App or BEO living App) but the ML devices are not reacting and therefore are not putting any audio out. Now puzzled how to make it all work, if possible at all. After reading all posts my best guess is that the BV7 should also be directly connected to NL with a BLC. If this the solution I have still the following questions about the best way to configure both BLC's:

• BLC BS9000 as VideoMaster?
• BLC BV7 as Audiomaster?
• Or the other way around?
• Or both as A.SLAVE or as Source center?
• Which App should be best controlled by the BLC's (ML Audiomaster, ML Videomaster, Essence)?

Hope all is clear enough and looking forward to your feedback.