Altec Best
My L & R cab's are Carmels with a 15" hole for a single 605. I added a port : 8"x3"x4" and sealed the box. The vol is about 6 cu ft. The center is also a 605, in a cab similar to an 861, 3.5 cu ft and ported. So that is why I developed the XO for 605s.
I have worked with Seadweller on an XO design for his 604Gs. Since he is in FL and I am in Chicago it was slow going, and we did not complete the project. I feel bad about that.
The test signal is a result of that work. So I wanted to share it with others.The test tone icon is after the schematic and has volume, FF, and Rewind controls. Your computer audio level control also is in the chain, so make sure it is turned up.

Don