|Acoustics of the saxophone
Bb tenor saxophone
Notes are the written pitch.
At frequencies below about 1 kHz, this curve looks rather like that for G5 and G#5, but raised in frequency. At higher frequencies, however, the situation is complicated by the cut-off frequency. Here, the 1 kHz cutoff weakens the third peak. The first peak is weakened, and mistuned in comparison with that for A4, by the open register hole (operated by the octave key). This is the lowest note to use the second register hole (near the mouthpiece). The saxophone has an automatic octave key.
Compare with the impedance spectrum for a soprano sax on written A5: same fingering but sounding one octave higher.
This sound spectrum includes transient excitation from the beginning of the note, and so has traces of a subharmonic being excited, seen in the range above 2 kHz (compare A4).
Sound spectrum of a Bb tenor saxophone played using fingering for A5.
For more explanation, see Introduction to saxophone acoustics.
You can hear A5 played.