Robert Harley’s book seems to be a positive encyclopaedia of audio, about 600 pages and 5th edition over 20 years. Two chapters on speaker set-up, covering about 75 pages. Not read it and don’t know his methodology. There is a whole thing about designing a listening room, which I scanned the other day in an article he put on TAS.
Personally, I use REW to measure the room and use DSP. Paul made a comment in the book against all-in-one systems, naming certain brands, saying they can do lots of things but nothing well. That will disappoint owners of Hegel, AVM, Devialet, Audionet, Vinnie Rossie, Mckintosh and no doubt many others, especially given some of these systems include programmable DSP that is much harder or impossible to do in component systems. It’s one of the reasons for buying such systems. To say nothing of active systems with DSP.
Building my new room, one of my issues is that Robert Harley and others usually assume people have stud walls that can be highly reverberant. In my room I have three brick walls and the rear wall will be 50% glass.