70-Volt Distributed Speaker Line

Tap-wattage budget, reflected line impedance (Z = V^2/P), remaining taps.

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Tap-wattage budget, reflected line impedance (Z = V^2/P), remaining taps, and run line-loss for a constant-voltage 70 V / 100 V audio line (NEC 640 / 725).

Constant-voltage line: total tap load = sum of tap watts; budget verdict total <= rating*(1 - headroom); reflected impedance Z = V^2 / P_total; line loss from wire resistance and the line current I = P_total/V.

Constant-voltage (70 V / 100 V) distributed-audio line design - tap-wattage budget, reflected line impedance Z = V^2/P, and run line-loss - per the standard 70 V distributed-system practice and NEC Article 640 / 725 (Class 2/3 audio) wiring, by name; first-principles Ohm's law.

First-principles Ohm's law. The amplifier spec governs the rated power and minimum load.

Estimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.

Field names used by the API: amp_rated_w, headroom_percent, tap_watts, tap_count, line_voltage_v, total_tap_w, budget_limit_w, reflected_impedance_ohm

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