# bandwidth vs. bandwidth range

As known, Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies. OK, what means when saying that bandwidth range is 15 ~ 20 KHz ? Does that mean that the bandwidth should be 5KHz ?

• Oh, come on, Dan! You know perfectly well that a baseband bandwidth of 10 kHz means that the (two-sided) spectrum of the signal is confined to $[-10^4, 10^4]$ Hz and this signal is not referred to as a signal of bandwidth of 20 kHz) while a passband signal of bandwidth 5 kHz has (two-sided) spectrum that is confined to $[f_c-2500,f_c+2500]$ Hz and to $[-f_c-2500,-f_c+2500]$ where $f_c > 2500$. Why are you creating a new notion of double-sided bandwidth? – Dilip Sarwate May 25 '20 at 16:13