View Full Version : Ported Rolloff Slope?

04-09-2003, 01:17 PM
If I've got 2 ported enclosures tuned to the
same frequency. One is 2.5cu ft and the other
is 3.75cu ft.

Will the larger enclosure yield a steeper rolloff
below the tuning frequency?

Also will the larger enclosure produce more SPL at the tuning
frequency compared to the smaller enclosure?

04-11-2003, 04:36 PM
TTT :)

04-12-2003, 12:47 AM
what is a rolloff slope, got any link to explain in detail if nobody wants to?
and whats this " +12dB/octave mean".... i forget

04-12-2003, 12:30 PM
Rolloff slope refers to a freq response curve where
the freq response of the speaker falls off and trails
down below a usable level. This slope can vary in degrees of
steepness. It's also used to describe x-over points.

12dB/octave commonly refers to a x-over point and how much
sound is cut out per octave above(HP) or below(LP) the
x-over freq.

For LOW-PASS: If you drop one octave below the x-over point a
12dB/octave roll-off slope will drop 12dB. Drop another octave and
your down 24dB from the x-over point.

The higher the number (36dB/octave) the more sound it
removes per octave beyond the x-over point. And the more
accurate it is at eliminating unwanted freq. Steeper Slope