Help understanding this ESS crossover

[joshmonger]

Hello everyone, I am hoping to maybe find some help with understanding this vintage ESS speaker crossover network. I am actually rebuilding one of the circuits isn't working well and I am not entirely sure the problem but that is not the main reason I want to understand this. I want to understand this because it sounds exceptionally well and I have a few other speakers projects around where I want to build my own crossover networks based of ESS's design (yes they sound that good). So anyway I measured and drew up a diagram and made a photo of it. I can't understand exactly it appears to be a third order crossover on the tweeter, but a first order on the woofer with a zobel circuit??? I don't know enough to be able how to understand how to use different orders and plugging it into an equation or calculator. It's completely baffling, the original manual specifies they are 6 ohm impedance but I can't seem to make an equation so I can modify it for other speakers. Can anyone help? Here is the schematic I drew up:



or try directly on dropbox:

https://www.dropbox.com/s/8tmknp9jruhls ... 2.jpg?dl=0

[meniscus]

You won't able to crossover referenced most professional crossover designs with simple calculator formulas. These designs generally use optimizing software that considers the impedance (resistance, capacitance & inductance) and the phase relationship of the drivers.

The circuit that looks like the "Zoble" is really more of a shaping circuit that can control the knee of the woofer roll off and tweaks the midrange to the designers liking.

Mark