Leave room for signal peaks
Headroom is the margin between operating level and the system limit. Music and speech are dynamic; their peaks exceed the average level. Sufficient capacity helps reproduce those peaks without clipping.
More headroom does not permit unlimited power. Thermal and mechanical transducer limits, load impedance and limiter settings still apply.
Convert decibels to a power ratio
Under equal conditions, a 3 dB increase requires approximately twice the power, and 6 dB approximately four times. A 25 W baseline with 6 dB margin gives about 100 W in an ideal model. This is an illustration, not a universal equipment recommendation.
P₂ = P₁ × 10^(H / 10)Read ratings with their conditions
Compare power ratings at the same impedance and test conditions. Peak, continuous and 100 V line ratings are not interchangeable. Audio output power also differs from electrical input consumption.
| Check | Design question |
|---|---|
| Output load | Is the amplifier rated for the required impedance or line voltage? |
| Power & protection | Are transducer limits and limiters defined? |
| Installation | Have cable loss and rack ventilation been checked? |
From estimate to selection
Enter target level, sensitivity, distance and headroom in the power tool. Check its result against the equipment data at the same output load. A laboratory sensitivity figure alone cannot describe performance throughout a room.
- Start from the application level, rather than the largest wattage label.
- For transformer lines, calculate tap totals and reserve capacity separately.
- Complete commissioning with clipping checks, limiter settings and level measurements.