What does 12 dB mean?

The smallest amount of electronic components that makes a low or high pass filter creates a slope of 6 dB per octave. That’s called a “one-pole” or “first order” filter. IF you double the components, you create a 12 dB per octave low or high cut filter and that is called “two pole” or “second order”, and so on.

What does dB per octave mean?

“Decibels per octave” is a way of expressing how quickly the response, or gain of a circuit changes as the frequency of the signal changes. This is a slope in the frequency response which can continue for several octaves, it doesn’t have to be just one octave.

What is a dB slope?

In audio filters, slope refers to how quickly frequencies are attenuated by the filter once the cutoff frequency is passed. A first order, or single pole filter will have a slope of 6 dB/octave.

What is slope for speakers?

Crossover rolloff (or slope) describes the rate which the audio level increases/decreases per octave as the frequency increases/decreases. It is usually given as a number (6, 12, 18, 24…) of dB per octave. Electronic crossovers commonly have a 12dB/octave slope.

What is a 12 dB slope?

A 12 dB per octave slope is a more gradual cut off and is sometimes useful in coupes or sedans that have the subwoofer(s) in the trunk. The rear seat material acts as a filter which can reduce upper bass range amplitude.

What does 1 octave higher mean?

To say that a note is one octave higher means to say that the note is the same, but it is in a higher section of the instrument. As the notes get higher, it is easy to see that the next C will be higher than the previous one. Whenever a cycle ends and the note returns to C, an octave is completed.

Which is better 6 or 18 dB per octave?

A 6dB per octave slope is useful for gentle shaping – a little less bright, a little less heavy, depending on whether the filter is high-pass or low-pass. 12 dB/octave is more useful in a creative musical context. 18 dB/octave even more so as you can cut out great swathes of frequencies and hear hardly anything that you don’t want left behind.

How to calculate the slope of a dB / octave plot?

Frequency f1can either be less than or greater than f2. The formula will work either way. Let dB be the slope with units of dB/octave from the lower frequency to the higher frequency. The formula is:        log2 dB/10 2 1 1 2f f y y (1)

What kind of filter does 12Db per octave mean?

A filter specified as 12dB/octave, however, is pretty certainly a 2nd degree Butterworth filter. Chebyshev and elliptic (Cauer) filters have ripple in pass and/or stopband instead of proper asymptotes and higher slopes, Bessel filters have much more linear phase response and lower slopes.

What is the rate of attenuation per octave?

For a low pass filter, higher frequencies are attenuated more. For this filter, the rate of attenuation is 12 dB per octave. An octave is a doubling of frequency.