The BL11 was targetted to be added to a BL4/6/8000/BV10/11/14 The Level was never designed nor intended to have an additional external speaker attached to it. All the internals are designed to match the speakers in the Level. Same thing as adding a Porche 911 motor to a BMW320. Also.. Geoff will haunt you for the rest of your days...  

Thank you for your response. I'm, of course, aware that Beosound level and Beolab 11 are from different generations and functionalities, but I also need to mention three aspects here that I believe play a role: 1- Bang & Olufsen's philosophy encourages integration, where Masterlink, network link and older versions of the links are good examples and mixing products from different generations has never been a problem from what I understand 2- Sound doesn't discriminate between old and new designs but is perceived by us as listeners. BS-level, for example, cannot reproduce the lowest signals with proper pressure due to its physical form, so adding a range of missing signals could potentially improve it. You are correct about the devices being balanced individually but within their physical capacities. It is clear, for example, that a three-way speaker sounds fuller than a two-way speaker as it covers the range of the sounds better/less compromised. 3- Finally, the perception of sound depends on the individual listener, which is why everyone in this forum suggests that we should listen to the speakers before buying. After listening to my BS levels, I feel that BL11 could improve the sound image (for my taste) Having all of this said, I do, of course, respect your view, while that is not what I asked. I wondered which technical solution could provide the best and most seamless solution to combine the speakers from a purely technical perspective.  

Think the short answer is that it is not possible (in any convenient way). Im not super technical but you need to get the left and right channels, at line level out from the Levels. I do not see how that could be done.

Honestly I never thought that I should be answering such a question ? I’d agree with the simple short post from Hiort….not possible! The only option I could think of is - like you mentioned - adding a CCA directly to the BL11 and then create a group of all devices. N.B. You’d need a trigger solution for the 11 as well. However, I am pretty sure that this among other things would cause delay issues between the 11 and the Levels……but testing is better than believing. Furthermore you would be limited to using Chromecast for streaming to the setup. And chromecasting means using the CC function within the source app - no way to integrate the Bang & Olufsen app there!   The “simpler or more elegant soltion” would be to get a Core (or an Essencense MK2) and some plain Beolabs to run along with the BL11 ?   MM

Thank you both Hjort and Millemissen, I’m getting a bit confused, So as a general question, if I for example stream music using B&O-app from a BS-core that is connected to Beolab 11, can BS-Levels be joined without delay?  If there will be a delay in such a system, what would it be caused by? After all they are supposedly using the same sound source, or are they?

Level has a delay to do equalization DSP (supposedly only in some orientations?).  But does this get applied to Line-In?  You should probably test this yourself: hook up a turntable or musical instrument to the Level's Line-In jack to see if it's noticeable. I believe the BeoLab 11 has zero delay.  But the 11 -- and of course the Level -- is not in @geoffmartin 's list of speaker delays at https://www.tonmeister.ca/wordpress/2017/12/06/bo-tech-beolab-loudspeakers-and-third-party-systems/ B&O TV's are supposed to correct automatically if you choose the speaker by name from a menu list.  But the Core?  Via the App?  Please let us all know...

A Level can join a core/essence mk2 with no perceptible delay via Network Link... I can listen to multiple NL devices, one being a Balance, without an "echo".   Not the path I went...  I bought two Balances, but you do you.  If you like the sound that is all that matters.

Thanks, Trackebo, for providing detailed information about the delay sources and Stan for confirming the functionality with the composite BS-Core + BS-Level environment. Now I need to get a Beosound core and keep my fingers crossed.

Looking forward to hear about what you’ll find out. There is no doubt that you can adress both these parts in the app - e.g. by activating the Core/BL11 and then joining on the Level pair. However - and that is what I meant above with “among other things” - you have no option of controlling the crossover between the BL11 and the Level. The BL11 only offers a minimum of settings there and the Level has its own ABL based bas management built in….meaning that this is variable = dependend on the SP of the device/how loud you play. This may lead to dips or peaks in the frequency response of the setup. However, if you can live with that or even enjoy the result - it will also very much depent on the room, where you listen and the placement of the BL11 - why not do it! Also the handling of the playback will be somewhat inconvenient - especially if you want occasionally to move one Level to another room and back etc. All in all not a setup that I would want……..or recommend! This said - I hope you’ll come back to tell about your impressions in case you make the setup. MM