An amplifier’s ability to go beyond its rated average power (RMS or continuous power) for a short time in order to recreate loud or explosive audio signals that rise very quickly. In order to have high headroom (an ability to achieve loud peak levels without distorting), and amplifier must have a solid power supply with a good amount of reserve energy on which it can call. he reserve power needed is similar to a car engine when passing another driver. A small car with a 100 horsepower engine may be able to travel at 60 miles per hour but will have difficulty speeding up to pass another car. A sports car with a 300 horsepower engine, however, will be able to quickly pull around the other car and accelerate to higher speeds with no difficulty. In such an example, the sports car has higher headroom than the economy car.eadroom, also referred to as dynamic headroom, is measured in decibels (dB). An amplifier with a rating of 3 dB can double its output power for peaks. So, if an amp were rated at 100 watts RMS (continuous) power, its peak power rating would be 200 watts with a headroom of 3dB. If the headroom were increased by another 3dB, there would be another doubling of peak power (to 400 watts in this example).ote that amplifiers with high headroom numbers are not necessarily better. In fact, most quality, high-end amps have headroom numbers of 3dB or lower. This is because those amplifiers have robust power supplies that can react to transients and sudden power demands within their continuous power envelope. The best amplifiers may have very low headroom figures of say 1dB or even less. Conversely, beware of amplifiers with very high headroom ratings, say 6dB. Such amps most likely use poor power supplies that only able to provide higher output levels for short periods of time.