Dull, thunderous, booming, deep, heavy, powerful, mellow, velvety, substantial, resonant, round, rumbling, dead, dry, hollow.
Due to its great dynamic range the timpani part must be precisely planned and regulated and carefully balanced with its partner instruments. This exactitude must be reflected in the notation. Although when played piano and mezzoforte timpani allow other instruments to the fore, it is very easy for them to drown them out in forte and fortissimo passages.
Basically the timpani sound is composed of two elements, the attack and the resonance. The resonance of a mf tone lasts about 4–5 seconds on the large drum and 3–4 seconds on the small one.
The timbre is determined by three factors: what the mallets are made of, where the head is struck and how hard the head is struck.
How the mallets influence the sound
A mallet with a small head stimulates the higher harmonics (which are inharmonic on timpani): the sound is brighter and more incisive. Wood drumsticks produce the same effect.
A mallet with a broad head stimulates the deeper harmonics: the pitch appears more definite (the first six partials are relatively harmonic), and the timbre becomes darker.
In funeral music muffled mallets are used.
The sound produced from different parts of the vellum
Ideally the vellum should be struck at a point a hand-width from the rim. This guarantees that the pitch remains clearly defined even in low tunings in which the pitch otherwise tends to lose clarity.
In general, the number of higher (inharmonic) partials decreases toward the middle the vellum, while striking the head on the rim stimulates them. The closer to the middle the vellum is struck the less definite the pitch becomes. If struck in the middle, the timpani sound like a drum.