Have you done a resonant modes analysis of your room, as must be done by Everest in the book you mention? (He does several in Sound Studio Construction on a Budget.) It shouldn't be over your head--just a bunch of divisions to get the modes for each dimension, then listing them in order of size, then looking at how they're spaced. If your 27' were 26', you'd be in some trouble and would need some kind of absorption at certain frequencies. You may anyway, but only a room analysis will tell. Speaker placement is important too, but that can be done by trial and error.
All this applies, roughly, to frequencies 300Hz and below. For above, absorption and/or diffusion will be called for, ideally. Everest should be clear on that. If by any chance you're handy with tools and have a workshop of any kind, I have DIY plans for one- and two-dimensional diffusors of the RPG kind, and for Argent Room Lens clones, which I'd be glad to email to you.
It's not rocket science, as they say, and I'd urge you not to give up too easily if Everest seems confusing at first. Good luck with the project!
All this applies, roughly, to frequencies 300Hz and below. For above, absorption and/or diffusion will be called for, ideally. Everest should be clear on that. If by any chance you're handy with tools and have a workshop of any kind, I have DIY plans for one- and two-dimensional diffusors of the RPG kind, and for Argent Room Lens clones, which I'd be glad to email to you.
It's not rocket science, as they say, and I'd urge you not to give up too easily if Everest seems confusing at first. Good luck with the project!