Regarding people who have noted certain sounds in certain keyboard locations with the Grotrian Concert Royal, it is normal and natural for the timbre and other sound characteristics to vary, sometimes very noticeably, in a real acoustic piano. The timbre of the notes can change abruptly when playing a chromatic scale for example, because of physical differences between the way the tones are produced at various ranges of the keyboard, from the low bass notes which are produced by single steel wires wound with a heavy copper coil, to those of the higher bass range which are produced by two wires instead of one, with smaller gauge copper, to the remaining mid and treble ranges that usually include three steel strings per note, not wound with copper wire. Various other mechanical details of an acoustic piano can also influence the sound; some dampers are at slightly different locations with respect to the piano keyboard, for example, because of the ribbing that provides strength to the heavy metal harp upon which the strings are strung and tensioned/tuned, and some strings (the highest treble notes) have no dampers at all.
In addition, certain speakers and headphones have pronounced resonances or peculiarities at certain frequencies or in certain ranges that can greatly increase the volume of some notes, or introduce distortion, accentuated overtones or rattling-like sound including mechanical deficiencies or problems with the box or headphone speakers themselves. Good reference speakers and headphones have a relatively flat response across their entire frequency range in order to minimize these problems, and quite a few of those recommended reference speakers and headphones are not that expensive. Some modern headphones have an exaggerated bass frequency response because many people who simply listen to music rather than to make music seem to prefer a strong and heavy bass, especially for some genres of music.
Anyway, I think that Pianoteq's Grotrian Concert Royal model is extremely convincing and beautiful throughout its range.
Last edited by Stephen_Doonan (07-11-2016 03:01)