AV Tools / Audio & Power

100V Line Calculator

Calculate power distribution and cable losses for 100V/70V constant-voltage speaker systems.

Projects
Pro
Amplifier
Speaker Types
1 type, 4 speakers total
Subtotal120 W
Cable Loss
Estimate power lost in daisy-chained speaker cable runs

Optional check for long daisy-chain runs

Results

System Status

120W connected to a 240W amplifier

Pass

Amp Power

240 W

Total Tap Load

120 W

Amplifier Headroom

120 W

50%

Speaker Count

4

Per Speaker Type

1 configured

SPK Type 130W × 4 = 120W
Diagram
100V Amplifier 240W output 1 30w Tap 2 30w Tap 3 30w Tap 4 30w Tap
How It Works

100V (or 70V) constant-voltage systems use a transformer on each speaker to step down the line voltage. Each speaker has a "tap" setting that determines how much power it draws.

Rule: The total of all speaker tap settings must not exceed the amplifier's rated power.

Headroom: A margin of 20–30% is recommended to avoid distortion and allow for expansion.

Disclaimer

These tools are provided in beta and are subject to change. All calculations and results may contain errors and should be independently verified by a qualified professional before use in any design, installation, or safety-critical application. AV500 accepts no liability for decisions made based on these outputs.