"Acoustics. With this made-up word derived from Greek one designates the doctrine of sound or that science that is concerned with the nature of sound and forms part of the science of nature. It is an auxiliary musical science covering 1) the way in which sound is produced, 2) the different genres and 3) duration of the same, 4) the velocity with which sound is reproduced, 5) the echo, 6) the sympathy of the tones, and 7) the special phenomena explainable by the known properties of sound" (Heinrich Christoph Koch. Kurzgefaßtes Handwörterbuch der Musik für praktische Tonkünstler und Dilettanten. Leipzig, 1807).
"Good acoustics" is not an absolute. Listening impressions and subjective judgments about was is thought to be pleasant, beautiful, or good are involved here. It has been known for thousands of years that certain physical laws underlie pleasant sound. Pythagoras identified the harmonic overtone structure of musical sound on his one-stringed monochord, and Jubal, the forefather of violinists and pipers, is mentioned in the Book of Genesis.
Ancient architects were experts in acoustics, and this we know on the basis of ear-witness evidence. Even today we can visit a Greek theater and experience how the speaker's voice carries into the very last corner without a microphone. During the baroque era curiosities like the whispering galleries described by Athanasius Kircher in detail in his Neue Hall- und Tonkunst (Nördlingen, 1684) evidently engaged the imagination.
A comparison of the general pauses in the autograph scores of Haydn's London Symphonies (whole rests) and those he composed for the Esterházy court (quarter rests) shows that composers consciously or intuitively made adjustments to the acoustic givens of the place of performance of their works. The reverberation in the historical London performance hall was much longer than that in the royal festival hall in Eisenstadt. At the dawn of the recording era, all parties involved had to put up with the limited horizons of the new technology. Pictures of a musician craning his neck at the horn on the early gramophones are well known: His instrument's voice?
Peripheral devices offering to the sound engineer countless means of sound improvement have been developed with remarkable speed ever since the early years of electric recording. One used to have to raise the levels in a recording transfer so that the sharper sound would cover all the cracking and crackling. The CD has eliminated such noise and led to a reorientation in recording philosophy. Away from productions in a sterile studio atmosphere and to recordings in selected rooms in natural acoustics!

[The way to the Classical-CD]