24DB 4th order ~75HZ Component Question

[mfrobel]

Greetings Fellow Users,
I am new here and I have a pretty basic question that I myself am having a bit of trouble with. I want to build a 4th order 24DB High Pass at ~75HZ for my Eminence Kappa Pro 12" speaker. Could some one please help me calculate the mH for the two inductors, uF for the two capacitors? Is there a calculator that I can use for these calculations? I hope I have posted this in the right forum section. Thank you in advance for any help you may have to offer

[wintermute]

I find this calculator useful --> Crossover Design Chart and Inductance vs. Frequency Calculator(Low-pass)

Be aware that you will need a very large inductor, and also that a theoretical filter that you get from the calculator won't necessarily be what you really need, as it will depend on what the response curve of the speaker is like, and the impedance curve as well.

at such a low frequency I would suggest you should look at an active crossover and separate amp for the bass driver.

Tony.

[mfrobel]

Very good! That was extremely useful. The box that I intend to build per the manufacturers instruction for the Eminece Kappa Pro 12A, is a large bandpass enclosure with a 24DB filter for the 12". I haven't figured out the rest of the networks yet. According to them, this is the way to get the most bass response without pushing the excursion limits. After all the speaker is really a very large mid bass. I intent to load the box with a 6" mid range, a horn, and a tweeter. The woofer, and mid will have their own manufacturer specified separate enclosures within the cabinet. It will be a fun project. I just thought I would share the fun! Thanks again.

Martin