It does not have to be in-walls.....
Option 1 - On walls
MONITOR AUDIO
https://www.monitoraudio.com/en/product-ranges/soundframe/
https://www.whathifi.com/monitor-audio/soundframe-1/review
MARTIN LOGAN
https://www.soundandvision.com/inwallspeakers/708ml
https://www.martinlogan.com/en/product/fresco
Option 2 - bookshelves that are designed and made to placed on a shelf or wallmounted
REGA R1 / RS1 /RX1 ( model in succession)
http://v2.stereotimes.com/post/the-rega-r1-loudspeaker
”....Immediate impressions are a clear and transparent portrayal with very high detail retrieval, fast and controlled transient response, and superb musical timing, both in articulating rhythms and tempi, and in placing instruments within the temporal flow and context of the performance. The RR125 is an outstanding mid/bass driver, sonically and musically right in line with the midrange performance of Rega’s amplifiers and phono cartridges. Get the midrange right and everything else will fall into place. Get it wrong, and all the king’s horses…
The Rega R1 becomes my new budget reference speaker. In addition of its ability to get the fundamentals of music right, it adds clarity and resolution, and an ability to lay out a vivid and coherent 3-dimensional stereo image. In small room applications, what more could you want?...”
https://www.analogueseduction.net/rega-upgrades-parts-accessories/rega-rs1-speaker-wall-brackets-pai...
http://v2.stereotimes.com/post/the-rega-r1-loudspeaker
http://www.rega.co.uk/rx1-loudspeakers.html
Option 1 - On walls
MONITOR AUDIO
https://www.monitoraudio.com/en/product-ranges/soundframe/
https://www.whathifi.com/monitor-audio/soundframe-1/review
MARTIN LOGAN
https://www.soundandvision.com/inwallspeakers/708ml
https://www.martinlogan.com/en/product/fresco
Option 2 - bookshelves that are designed and made to placed on a shelf or wallmounted
REGA R1 / RS1 /RX1 ( model in succession)
http://v2.stereotimes.com/post/the-rega-r1-loudspeaker
”....Immediate impressions are a clear and transparent portrayal with very high detail retrieval, fast and controlled transient response, and superb musical timing, both in articulating rhythms and tempi, and in placing instruments within the temporal flow and context of the performance. The RR125 is an outstanding mid/bass driver, sonically and musically right in line with the midrange performance of Rega’s amplifiers and phono cartridges. Get the midrange right and everything else will fall into place. Get it wrong, and all the king’s horses…
The Rega R1 becomes my new budget reference speaker. In addition of its ability to get the fundamentals of music right, it adds clarity and resolution, and an ability to lay out a vivid and coherent 3-dimensional stereo image. In small room applications, what more could you want?...”
https://www.analogueseduction.net/rega-upgrades-parts-accessories/rega-rs1-speaker-wall-brackets-pai...
http://v2.stereotimes.com/post/the-rega-r1-loudspeaker
http://www.rega.co.uk/rx1-loudspeakers.html