I have the 90s. Previous to that the BL5s. the 90 and the 50s have settings in the BeoApp which enable threshold trigger on/off and source priority. I use the BL90s with a Beovision (Beosound Theatre) via DPL and Auralic DAC/Streamer (XLR). The triggers are set for priority XLR, the DPL (set your most used source last). The BL90s trigger on XLR signal and (IIRC, 30sec after no signal trigger off). Via DPL, it’s all controlled by the Beovision. Obviously, you will need to control your 3rd party source with a non-BeoRemote but one problem you will have is controlling your 3rd party streamer volume. I keep my Auralic DAC at 100 volume, fixed, max 4.8v output. The use of a BR1 is a PITA if using a Beovision as you have to switch modes. To get around this faff, I installed an Essence Remote (in IR mode) and a Beolink IR eye. That’s OK but a little sluggish. A Halo solved that problem via Wi-Fi control. I think a second BR1 in Beosound mode may also work well but I’ve never tried that.

Thank you so much for your enlightening post. I understand that there still a need for some trickery. I realize the complexity is dictated by many diverse factors but I was hoping in a more elegant solution nowadays. Unfortunately I don’t have any other B&O hardware in the chain. Just the speakers and BR1.  If it only allowed me to set different start volume corresponding to each source, that would have done it for me. Perhaps I should have gotten a Halo instead of the BR1?

I would check with your dealer on the controllability of BL50 with BR1 directly. It may be there as BT control. I can’t tell because of the Beovision connection. All else on the triggers/threshold remains and is easy. Ditto the 3rd party App controlling your music. If you clarify the BR1 issue, you will find it straightforward enough to operate and enjoy.

I have bl50s, and a 3rd party streamer/DAC connected directly via RCA. You can add an IR eye in/behind the side panel of your master 50 speaker, and the BR1 (set to Beosound mode) can then control its volume. (you can play/pause etc also with the BR1, but not with an analogue RCA source obviously, so just volume in that case). Its ok, not brilliantly responsive but it does work - depends on how direct line of sight the BR1 has of the panel where you've hidden the IR eye. A BR Halo now can (volume) control the BL50s using wifi - that may be a touch more responsive. But unless you can find a Halo on a cheap deal, 700GBP is a lot to spend on a volume wheel product, when all the rest of the things the Halo can do are not usable for you.  

and of course, just to add that the bl50s do not have BT, hence the need to use something else (Wifi or IR). Not sure what your audio source is?

Ok, now that the BL50 have been installed (overwhelming to say the least!) I’ve understood a little more on what you all meant. It works reasonably well although the difference in volume between RCA and spdif is huge, it still is manageable with 3rd party. Thanks again for your inputs.

As we share the same challenge how to control volume with 3rd party devices, I have tested all 3 remotes options: BR1, Halo, Essence remote. With the IR-Eye and the BR1/Essence Remote I liked the Br1 more, for what ever reason the Essence remote had always some lag in response. Put it back into the drawer. With the Halo you have some more options, you could select the input as well as the sound profiles. However, just for that purpose, a hefty price point.