# What's the name for the type of x-axis scale used in frequency graphs?

I'm talking about the way the spacing between frequencies typically shrinks as the x-axis increases on frequency graphs. For example, in the graph below, the leftmost (labelled) x-axis interval represents only 20Hz (between 30 and 50), but the rightmost one represents 10,000Hz (between 10k and 20k).

I'm 99% certain there's a word for this type of scale but I'm having a complete brain failure and I've forgotten what it could be...

• I'm pretty sure it's logarithmic. – Linuxios Feb 2 '17 at 3:39
• It is a logarithmic scale, frequently used when representing frequency or decibels scales. – Hagan Feb 2 '17 at 8:12

## 1 Answer

It's a Logarithmic scale & is used where a linear scale wouldn't really make sense & would reduce the detail in the lower portions of the graph.

As each octave doubles the frequency. The difference between, say, 50Hz & 100Hz is an octave, so is the difference between 5kHz & 10kHz.

If that information were to be presented on a linear scale, there would be so much space needed to represent the octave from 5-10k that the information for 50-100Hz would be lost way down the left hand side.

• I would add that the logarithmic scale a more accurate representation of our perception of the frequency spectrum. – Marc W Feb 2 '17 at 14:43