View Full Version : Ported Rolloff Slope?

ShaunMac

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?

ShaunMac

04-11-2003, 04:36 PM

TTT :)

more_spl

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

ShaunMac

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