What is the difference between Watts Rms & Watts Aes?


Now maybe I'm not the best person to speak to about this topic but will give you a crash course on the topic, though if this is of more interest to you for what ever reason I hope to remove some myth around Watts. None the less here it goes and I will include how this effects audio beyond what you might realize. 

here's an explanation of the difference between watts RMS and watts AES when measuring the power handling capacity of loudspeakers, including some of the AES standards:


Watts RMS and watts AES are both units used to measure the power handling capacity of loudspeakers. The main difference between the two is in the way the measurement is taken.

Watts RMS is a measure of the average power that a loudspeaker can handle over time without being damaged. This measurement is typically determined by applying a continuous sine wave signal to the loudspeaker and gradually increasing the power until the loudspeaker starts to distort or become damaged. The power handling capacity is then expressed in terms of the maximum power that the loudspeaker can handle without exceeding a specified distortion level. This maximum power is typically expressed in units of watts RMS.


Watts AES, on the other hand, is a measure of the maximum power that a loudspeaker can handle without being damaged when subjected to a specific test signal. This test signal is typically a band-limited noise signal with a specified crest factor, and the measurement is taken at a specific distortion level. The power handling capacity is then expressed in units of watts AES.

The Audio Engineering Society (AES) has defined several standards for measuring the power handling capacity of loudspeakers, including the AES2-1984 (r2003) standard for measuring continuous pink noise power rating. This standard specifies the use of a continuous pink noise signal with a specified bandwidth and level to measure the maximum power that a loudspeaker can handle without exceeding a specified distortion level. The power handling capacity is typically expressed in units of both watts RMS and watts AES.

Another AES standard is AES2-2012 (r2017), which specifies the use of a pink noise signal with a crest factor of 6 dB and a specified bandwidth to measure the thermal power rating of a loudspeaker. The thermal power rating is the maximum power that a loudspeaker can handle without being damaged due to thermal overload. This rating is typically expressed in units of watts AES.

The AES standard AES2-1984 (r2003) for measuring continuous pink noise power rating, for example, uses a continuous pink noise signal with a specified bandwidth and level to measure the maximum power that a loudspeaker can handle without exceeding a specified distortion level. This standard specifies that the loudspeaker be tested for a specified duration, typically 2 hours, with the power gradually increased until the distortion level is exceeded. The maximum power that the loudspeaker can handle without exceeding the specified distortion level is then expressed in units of both watts RMS and watts AES.

In summary, watts RMS and watts AES are both units for measuring the power handling capacity of loudspeakers, with watts RMS representing the average power over time that a loudspeaker can handle without being damaged, and watts AES representing the maximum power that a loudspeaker can handle without being damaged when subjected to a specific test signal. AES has defined several standards for measuring the power handling capacity of loudspeakers, including AES2-1984 (r2003) for continuous pink noise power rating and AES2-2012 (r2017) for thermal power rating. The power handling capacity is typically expressed in units of both watts RMS and watts AES, and the measurement method can significantly affect the outcome of the power handling rating of a loudspeaker.


The Audio Engineering Society (AES) standards were introduced within broadcasting and recording to provide a common set of guidelines for audio professionals to follow when designing and producing audio equipment and content. The standards help ensure that audio equipment and content meet certain technical specifications and performance requirements, which in turn helps improve the quality and consistency of audio reproduction.

In the context of loudspeakers, the AES standards for measuring power handling capacity were introduced to provide a more standardized and reliable way of measuring and rating the power handling capabilities of loudspeakers. Prior to the introduction of these standards, manufacturers often used their own methods for measuring power handling, which made it difficult for consumers to compare and evaluate different loudspeakers.

By establishing common testing procedures and criteria for measuring power handling, the AES standards make it easier for consumers to compare loudspeakers from different manufacturers and make informed purchasing decisions based on accurate and consistent information. Additionally, the standards help ensure that manufacturers are providing reliable and consistent power handling ratings for their products.

Overall, the introduction of AES standards has had a significant impact on the quality and consistency of audio equipment and content within broadcasting and recording industries, helping to standardize technical specifications and performance requirements and improving the overall quality of audio reproduction.