# butterworth 4th order setup in minidsp



## apilon (May 18, 2006)

Good afternoon 

Am i understanding correctly that if i want to set a butterworth 4th order in minidsp then i need to set the slope to 24db/oct and 48db/oct would be considered buttrworth 6th order?

Reason i am asking is i was reading about setting hpf for a vented sub and the article mentionned that you should set the filter to 1/2 octave so since my sub port is tune to 23hz 1/2 octave is 17.25hz but at 2nd order butterworth the cone excursion goes way pass the xmax of 29 mm so i need to set it at a 4th order butterworth to get it under xmax value 


Alain


----------



## Wayne A. Pflughaupt (Apr 13, 2006)

If you are asking if 48 dB/octave is a 6th order slope, the answer is no – 6th order would be 36 dB/octave. 48 dB/octave is 8th order.

Regards, 
Wayne


----------



## apilon (May 18, 2006)

Wayne A. Pflughaupt said:


> If you are asking if 48 dB/octave is a 6th order slope, the answer is no – 6th order would be 36 dB/octave. 48 dB/octave is 8th order.
> 
> Regards,
> Wayne


Thanks so what would be 4th order then ? 

12db is 2nd order right ? 

Alain


----------



## JohnM (Apr 11, 2006)

Multiply the order by 6 to get the slope.


----------



## apilon (May 18, 2006)

JohnM said:


> Multiply the order by 6 to get the slope.


Thank for the explanation 

so if in minidsp i set hpf to butterworth 48db/oct i just then set a 8th order butterworth if i understand correctly


----------



## AudiocRaver (Jun 6, 2012)

apilon said:


> Thank for the explanation
> 
> so if in minidsp i set hpf to butterworth 48db/oct i just then set a 8th order butterworth if i understand correctly


Correct.


----------

