How loud and soft tubas play!

[SRanney]

And I'm assuming everyone's in phase.

While I am not a acoustical engineer, I learned (albeit a long time ago) that to be in phase, two or more people must be playing at identical frequencies. Identical. Even in professional brass sections playing in unison, how often do you think this happens?

[kingrob76]

You can't tell the difference between 31 and 32 violins.

I can tell. The latter requires more ammo to sufficiently address their intonation issues.

[Rick Denney]

You can't tell the difference between 31 and 32 violins.

I can tell. The latter requires more ammo to sufficiently address their intonation issues.

Hey, I said Jonathon can't tell. I wasn't talking about you.

Rick "scared of Rob" Denney

[DonShirer]

Although decibels are a common measurement of sound pressure level (SPL), they are not a measurement of perceived loudness. For that, acousticians use the unit of a phon (loudness level) or the sone (loudness). The sone has the advantage of being additive, i.e. a sound of 2 sones plus one of 3 sones give a perceived loudness of 5 sones. Both are frequency dependent: At 1000 Hz, a change of 10 phon is equivalent to 10 db, but 30 Hz it is a change of about 5 db at moderate sound levels. 40 phons is arbitrarily set equal to 1 sone, and increasing the loudness level by 10 phons, doubles the perceived loudness (i.e. to 2 sones). So it takes 10 violins (playing at the same level) to sound twice as loud as 1 violin.

A just noticeable difference of SPL is about 1 db for very soft sounds and about 1/2 db for loud sounds in the tuba range of frequencies according to published tests. However, in a actual performance situation with the distraction of many different instruments playing, Rick may be right to say that it would take a bigger change, maybe 3 db to produce a noticeable change (less than double) in loudness). Many experts quote the width of a musical dynamic level (ff to f, say) is about 6 db, so a total range of about 30 db is necessary for 5 dynamic levels (Rick's soft to loud range), for an intensity change of about 1000:1. However a 1965 study showed that many good musicians can only produce ranges of less than 15 db, with the woodwinds being the worst off. At that rate, Neptune's average 30 db range between pp and ff for a tuba is pretty good!