Simple Explanation

The reduction in power transferred from an amplifier to a loudspeaker as the speaker's voice coil heats up, increasing resistance and lowering the power output.

Concise Technical Definition

Power compression is a phenomenon where the power transfer from the amplifier to the loudspeaker decreases as the voice coil heats up. As the coil heats, its resistance increases, which reduces the effective power output for the same applied voltage. Typical compression values range from 3 dB to 6 dB.

Layman-Friendly Analogy

Imagine trying to push water through a pipe that’s heating up—over time, the water can’t flow as easily because the pipe expands. In a speaker, as the voice coil heats up, it becomes harder for the amplifier to push power through, reducing the output.

Industry Usage Summary

Power compression is an important consideration in audio engineering, especially for high-power systems and loudspeakers. As the voice coil heats up during sustained loud sounds, the speaker’s performance can degrade, with reduced volume or clarity. This effect is more pronounced in long or high-output performances, like concerts or sound reinforcement systems. Managing power compression is key to ensuring consistent sound output and protecting speaker components from heat damage.

Engineering Shortcut

The reduction in power transfer due to increased resistance in a heated voice coil.

Full Technical Explanation

Power compression occurs when the voice coil of a loudspeaker heats up due to prolonged or high-power signals, causing the resistance of the coil to increase. This results in less power being transferred from the amplifier to the loudspeaker, even if the applied voltage remains constant. As a result, the loudspeaker's output diminishes, leading to a perceived reduction in volume or clarity. Typical power compression values range from 3 dB to 6 dB, and it is a common issue in high-power sound systems. Understanding and managing power compression is crucial for optimizing speaker performance, preventing overheating, and maintaining consistent sound output during extended use or under heavy load conditions.