Accurate reproduction requires flat response at near-original playback levels

Evidence

Nevertheless, they cannot be ignored in sound reproduction. For a sound reproducing system to accurately portray what was heard in a live performance it must have a uniformly flat frequency response and reproduce the sounds at 256. or close to the original sound levels, so that our built-in loudness processes operate on the sound in the same way. This is where complications set in, because that is rarely the case. Even if our sound systems have flat frequency responses, the playback sound levels are not likely to be what they were at live performances or in recording control rooms where important artistic decisions were made. For recreational listening, sound levels are almost always lower, often much lower, than the “original” sound. — Toole, Floyd E, Sound reproduction- the acoustics and…, 910

Categorization

• XREF: This is the classic loudness-matching problem relevant to home-listening vs reference-monitoring debates.