[William Sommerwerck]

But no matter how good the equipment and recording techniques,
the program in recordings will be masked by room issues if the
equipment is listened to in an untreated room. Guaranteed.

You're overstating the case. "Masked by" -- without qualification -- implies
it isn't audible at all. Which is not true. It's rather that the better the
setup (including treatment), the more one can hear what the recording
"really" sounds like.