What's new

What is an octave? (1 Viewer)

eryn shannon

Stunt Coordinator
Joined
Jan 22, 2004
Messages
62
If a subwoofer plays 2 octaves below your main speakers what does this mean? Is 1 octave a specific number of Hz?
 

Craig Chase

Gear Guru
Joined
Oct 21, 2002
Messages
1,774
Location
Pennsylvania
Real Name
Craig
An Octave is the doubling of frequency... for example, 300 Hz is one octave above 150 Hz... and the 150 to 300 Hz range of tones represent one octave.

We also have the human hearing scale...

20 - 40 - 80 - 160 - 320 - 640 - 1280 - 2560 - 5120 - 10240 - 20480 Hz...

We have a hearing range of about ten octaves...as shown above...and if your main speaker can play to, for example, 80 Hz, and a subwoofer adds 2 octaves, it would play to 20 Hz...
 

Chu Gai

Senior HTF Member
Joined
Jun 29, 2001
Messages
7,270
And you may have also heard of things like 1/3 octave as in 1/3 octave equalizers. One might think that is nothing more than divvying into numerically equal thirds the spaces between two octaves. However it doesn't work like that.

While in a 1/3 octave equalizer, the spacings are three to an octave, they are spaced by the cube root of 2 = 1.2599. An example of frequencies spaced by 1/3 octave would be: 20hz, 25.2, 31.7, 40, 50.4, 63.5, 80 and so forth. Note how every third number (20, 40, 80) is another octave (doubling).

20 * 1.2599 = 25.2
25.2 * 1.2599 = 31.7
31.7 * 1.2599 = 40

Make sense?
 

Users who are viewing this thread

Forum Sponsors

Forum statistics

Threads
346,090
Messages
4,766,542
Members
141,672
Latest member
BAMatter
Top