Bass trombone

What it is

The trombone with a wider bore, a larger bell and two valves that lower it to F and to D (or E-flat); the bass of the trombone section.³

Range

Bb0 to F5³29.1 Hz – 698 Hz

VSL, including pedal notes Bb0-Bb1. Two valves lower it to F and to D (VSL also says E-flat or D for one of them).

Overtones reach about 4.04 kHz (the highest harmonic within 40 dB of the strongest, at a moderate level; louder playing reaches higher)⁴.

Where the sound comes from

• bell: faces along the bell axis (backwards on the horn); very directional^6,2

• The highs beam straight out along the bell axis; off axis sounds darker.^6,2

Where the sound goes

Bell rim 22.8-26.7 cm. Pätynen and Lokki measured only the tenor trombone and expect the bass trombone to behave the same, "only scaled to lower frequencies due to the larger bell" (about a third larger than the tenor's 18 cm); on the tenor the 125 and 250 Hz bands radiate almost all round and from 1 kHz up the sound is concentrated along the bell axis.^3,7

About the range

Bb0-F5, with pedal notes Bb0-Bb1; VSL's registers: low to F2, "powerful metallic sounds"; middle F#2 up, slightly darker than the tenor; high from F#3 or F#4 (VSL gives both) to F5.³

How loud

Sound pressure level measurements as published. Different kinds of figure (a playing level, a peak, a dose at the player's ear) can't be compared with each other, and neither can figures at different distances.

Sound power at forte, from ISO 23591 Annex A: 105 dB (unweighted), one dB above the tenor trombone's 104 and the highest in Skalevik's table; about 98 dB(A) of direct sound at the player's ears.⁵

Recording it

No bass trombone-specific source found; the trombone's advice applies.

Mics i

No mic is named by more than one source yet: each names its own.