# What is an octave? It is said to be eight, but I cannot see the eight anywhere

When I searched for octave, I listened to the fact that if you take an octave band the lower cutoff is double the upper cutoff.

Where is this name octave coming from, that is, where does the figure eight show its significance in the above statement?

In the same way, if the above is clarified, I have some doubts on 1:2 and 1:3 octaves.

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It took me a while to figure out your question... You are puzzled by the fact that the latin root of "octave" implies "eight" while in signal processing terminology it refers to ratios of two, right? – pichenettes Dec 23 '13 at 9:20
I had the similar doubt...and I thought 10 -2 =8 makes octave will do.. – dexterdev Dec 23 '13 at 9:48
ok @pichenettes that's what really teased me octave is eight,so you mean to say it will also mean a ratio of 2 – kakeh Dec 23 '13 at 10:19
In signal processing terminology an octave refers to a ratio of 2 or 1/2 between two frequencies. For example: A band-pass filter with a center frequency of 400 Hz is said to be "one octave above" a band-pass filter with a center frequency of 200 Hz. – pichenettes Dec 23 '13 at 10:35
Do Re Mi Fa So La Ti Do. Eight notes: octave – Dilip Sarwate Dec 23 '13 at 20:26