My external crossovers have 1 single input pair from the amp and 2 output pairs from the board to the 2pr of terminals mounted to the back of the speaker cabinet.
The leads from amp to crossover are 6 ft. The leads from the crossover to the speaker cabinet are 30in. The speakers rest on Sistrum stands the crossovers on Sistrum platforms all direct coupled to the floor for maximum resonance grounding. TomD