The 2nd version has a curved broadband LF absorber between the speakers which makes the long walls completely non-parallel, this may be preferred acoustically, but offers less storage space for Jim, its his call. About 2/3 of the long wall is non-parallel even with the storage option, and behind the listening seat is an absorber/diffuser to help mitigate that aspect.
The plan view doesnt show that the record storage across the left corner is not full height. It is proposed to have fabric fronted openings above and below with into the space behind to provide a bass trap. The storage will provide a little welcome diffraction without too much absorption, which is generally welcome on the wall behind the speakers.
It is also planned to have diffraction between the windows on the side walls, and some absorption/diffraction on the ceiling, although with horns and their radiation patterns they are likely to be less effective than with some other types of speakers.
Domestic hifi rooms are always a balance of compromises. @Jim like’s the sweet spot, so achieving room symmetry for the mid and high range was a high priority, along with a balance of absorption and diffraction and a room which could look very nice and wouldn’t be overly dead sounding.
Could that curve be the other way around, ie concave rather than convex Simon? Just to literally add some depth behind the speakers - at the old place they were placed outside the bay with the entire depth of the bay behind them.
I didn’t realise the importance of a room for many years.
Place we lived in Plymouth was fantastic, every pair of speakers used in it worked well. The next place was useless.
God knows how much money gets wasted on hifi because the room is no good
@Jim just a thought; I’ve been looking into acoustics a bit lately, wondering if there is an external wall construction that is better suited for dealing with sound, in particular bass. Solid blockwork/masonry bounces back a lot of the low freq. energy into the room, which you then have to deal with using traps etc. I’m wondering if a metal stud internal lining with say, 200mm Rockwool before the outer skin of brick would help?! I’m guessing you want to use brick externally to match the house.
