Musical timbre is the term we use to describe the sonic qualities that distinguish one instrument or voice from another. It's a complex and subjective quality that includes the harmonic content (the collection of overtones), the attack and decay of the sound, and the envelope of the sound (the pattern of changes in loudness over time).
Examples of musical timbre include the warmth of a saxophone, the bright and piercing sound of a trumpet, the rich and mellow sound of a cello, or the percussive sound of a drum. The human voice can also vary greatly in timbre, with differences in pitch, tone, and vibrato.
Incomplete timbre, also known as "breathy" or "thin" timbre, can occur when a sound source does not produce a full range of harmonics. For example, the sound of a flute can have incomplete timbre, as it produces a series of harmonics that are not evenly spaced. In contrast, overblown timbre can occur when a sound source produces too many harmonics, resulting in a harsh or abrasive sound. This can happen when a wind instrument is played too loudly, or when a signal is not correctly produced in an amplifier design.
In a high-end audio system, the amplification chain and loudspeakers can have a significant impact on musical timbre. The amplifier's design, power output, frequency response, damping factor, interrelationship with the speaker's impedance, and distortion characteristics can all affect the timbre of the sound produced.
In my experience, it is important to select an amplifier and loudspeaker combo that are honest and faithful to the preservation of musical timbre.
There's a lot to get right and even more to get wrong if we're not careful in our designs.
In any music system or recording, timbre is one of the easiest qualities of music to identify as either right or wrong.