Speaker cab wiring schema
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The topology is relatively straightforward: a series/parallel arrangement for the speakers, with the Midax horns over the top. The 2uf capactitors filter out the low frequencies, protecting the horns from excesses of bass.
For the maths underlying the circuit (impedances and so on), see the notes on this page.
The arrangement of the wiring is clever. If either or both of the horns fail, all four speakers remain in circuit. In addition, if one pair of speakers fails, the other remains active, though the impedance of the cab rises to 32ohms.