Current situation: space available for records and CDs on current stock of Expedit = 20.5 squares given other stuff.
Space required for current stock of records and CDs: more than that.
Given that, does anyone know CD storage options¹ out there, possibly wall mounted, that are worth having and will fit into an accountant/engineer’s aesthetic tastes?
¹ As my CD player is better than my DAC in the main system and they are already ripped for use in the mancave system, the loft is not the answer.
Probably no help,but I have expedit with a couple of doors so don’t have to see them.
Utterly hopeless if I want to use them as they are just stacked.
Luckily I don’t play them.
I started out with a pair of 4x4 and a 4x3 Kallax. But quickly ran out of space. I put a couple of 2x4 on top and then squared things off with 1x1 kallax boxes. It is all solid as a rock. See if you can go up with your Kallax to create more space.
Before I had some storage made for me, I was interested in this kind of set-up:
The basement? 
My final solution is the now defunct Ikea Benno CD rack, but still plenty available used.
No doors, so you need to dust it off from time to time. On the plus side, you have a complete overview of the collection. Not wall mounted though. (But secured with a screw on the wall.)
In various colours, including black, blue or silver. Example from the web in wood:
PS: if you choose silver, be aware that they used various shades of silver over time. It did bother me then, but now not any longer.