|Acoustics of the saxophone
Bb tenor saxophone
Notes are the written pitch.
Compare with the impedance spectrum for a soprano sax on written C4: same fingering but sounding one octave higher.
In the sound spectra for the low notes, we can notice a sudden increase in the negative slope of the spectral envelope that occurs close to the cut-off frequency of about 800 Hz. For general comments about the sound spectra of the first register, see A#3, which is the first note of that register.
Sound spectrum of a Bb tenor saxophone played using fingering for C4.
For more explanation, see Introduction to saxophone acoustics.
You can hear C4 played.