How to design a high end crossover…

Oh heck yeah. Below is a link to a free online circuit calculator for a third order Butterworth, and this has no Zobel circuits or notch filters.  

Second link is to Humble Homemade HiFi for pictures of some of their more advanced x-overs.

https://www.omnicalculator.com/physics/crossover?c=USD&v=filter_order_type:0,additional_circuit:0,spread:8,type:3.000000000000000,filter_order_type_3_way:3.000000000000000,woofer_impedance:4!ohm,midrange_impedance:8!ohm,tweeter_impedance:6!ohm,crossover_freq_low:500!Hz

http://www.humblehomemadehifi.com/assembly.html

This photo shows one of their designs that incorporates cheap to expensive inductors for their specific attributes, and bottom drawer to top shelf caps.

It's a science that’s an art.

http://www.humblehomemadehifi.com/services/assembly_99.jpg

https://www.marchandelec.com/ has lots of useful information on building passive or active crossovers.

I wind my own inductors. Easy peasy.

I have a capacitance board. Any value +/- 10 uF.  Same for non-inductive resistors.

I always use 2nd order. Not L-R.

Its painless.

@wolfie62

Specific to bass reproduction.

I just received 5lbs on 12 ga inductor wire yesterday, 14, 16 etc coming. I have two lathes and am building a setup for the small one to do this on. This will help out with costs when you make 4th order, specific, to eliminate the need for a notch filter.

I’m also interested in trying absolutely everything at a particular number, I’ve chosen 1.2 mh, that I can use to determine pluses and minuses, the only ones I don’t have yet are a 10ga foil wound and a 12 ga Litz wire, but am ordering the Litz tomorrow, Solen, with my regular order from that supplier.

In a closed range measurement, 20-200 hz for extra precision, the foils are superior in my results. Not so much by manufacturer though, Dayton’s are not bad at less than ½ the price of some others.

All of this is not going to go to waste, after I scratch this itch, I’m using some existing good quality orphaned drivers for testing, as well as existing speakers I have, and will build some speakers out of the parts and sell them if I don’t replace my existing speakers with them.

This is where the DSP comes in handy, as great inductors for subs are ridiculously expensive, and I find them perfect for subs. I just wish more sub makers would consider that many people are buying dual subs now, and so make the upper range XO on the smaller ones at 200, so they can make an excellent combo with small bookshelf speakers, where the sub is used as part of the speaker stand.