Do a 6th order filter ...
Quote:
Originally Posted by
Lee in Montreal
BTW The intent of the project is to be flat fro 30Hz to 800Hz.
... and end up at 22 Hz. You need an electronic xover which can give You the missing two orders: 4 orders come from the box, and two from electronic filtering.
See the Thiele papers.
Ruediger
It's easier than You may think.
Quote:
Originally Posted by
Lee in Montreal
Hi Ruediger. You lost me here ;-) How will the 12db electronic crossover affect the lower end? Do you mean a small "bump" down there?
General Audio Discussions -> Technical References Thread -> Thiele Papers Part I -> Page 6 resp. 186: "Sixth-Order Butterworth Response". See also Figure 6 on page 8 resp. 188.
A filter of any order can be achieved by chaining filters of order one and two. Four orders will be supplied by the box, and two by the electronics.
You even have three choices, which two of the six orders You handle by electronics, and which four by the box. Not all of these choices will always lead to a good design.
There is a good design in the tables of that paper.
May I say "EV DX-38" again?
Ruediger