Distributed Speaker Load Calculator
Sum distributed speaker transformer tap loads and compare the result with an entered amplifier rating and headroom.
Enter tap and amplifier ratings
Speaker transformer taps
Amplifier capacity estimate
About this calculator
Enter the line-system voltage, each loudspeaker’s transformer tap wattage, amplifier output rating, and a design headroom percentage. The tool compares total tap load with the headroom-adjusted rating.
Use the tap setting planned for each speaker, not its impedance or maximum label rating unless that is the selected tap.
Method and assumptions
Total tap load is the sum of all entered speaker tap wattages. Required amplifier output = total tap load × (1 + headroom percentage ÷ 100).
This is a simple steady-load wattage comparison. It does not account for cable losses, transformer insertion loss, program duty, amplifier environmental derating, or equipment-specific design limits.
FAQs
Should I enter speaker impedance or tap wattage?
Enter the selected transformer tap wattage for each speaker. This worksheet does not calculate impedance from speaker taps.
Does a passing result establish an emergency voice system is approved?
No. System approval and intelligibility, supervision, wiring, and equipment requirements need a separate design review.
Sources
Use speaker transformer tap and amplifier output data from the exact product documentation.