Understanding a speaker’s power handling capacity

Klipsch RF-7 MKII

Should you consider a speaker?s power handling capacity before making a purchase? Can you use an amplifier whose power handling capacity exceeds that of the speaker? Why does power handling vary so much from one speaker to another? How is a speaker?s power handling capacity measured’ How powerful should an amplifier be in relation to the speakers? Here are our answers to these questions.

What is power handling?

The electrical power handling of a speaker is directly linked to the size of its drivers? copper winding. If an excessive amount of electrical current travels through the coil, the latter will overheat and melt. In this case, the speaker would be greatly damaged, while the amplifier might also sustain irreversible damage if not fitted with a protection circuit. Most manufacturers therefore indicate the power delivered by their amps and handled by their speakers.


How is a speaker?s power handling capacity measured’

It is determined by the speaker?s manufacturer according to the characteristics of the driver bearing the biggest coil. Most of the time, this is the bass driver. Tweeters, designed to emit high frequencies, feature light, flexible components and therefore have a smaller coil. When Elipson specifies a power handling of 150 Watts for the Elipson P4i, they are referring to its two 8″ drivers, as the tweeter can probably only handle around 50 Watts at the very most. Due to the fact that low frequencies require a lot more energy, the amount of power sent to the bass drivers is always much higher than that sent to the tweeter. The distribution of power to the different drivers is carried out by the speaker?s electronic crossover filter. It prevents, for instance, the tweeter from receiving low-frequency signals. Since the reproduction of bass frequencies necessitates most of the amplifier?s power, it is not rare that the tweeter receives only one Watt from the 20 W delivered by the amp.

Tannoy XT6F

The Tannoy XT6F floor-standing speaker, featuring a power handling capacity of 75 W. A number which may seem low, yet is amply sufficient and, above all, realistic.

Why do comparable speakers sometimes display different power handling capacities?

Some manufacturers only indicate the drivers? electrical power handling capacity, while others indicate the power handling capacity of the drivers while in operation (such as Tannoy or Klipsch, for example). It is important to note that a driver?s power handling capacity differs from that of the speaker.

The operational functions of a speaker determine its power handling capacity.

Let us explain. The presence of a significant  amount of air equates with a longer excursion of the cone. A driver?s cone moves within a precise excursion range, beyond which the mobile parts would be pushed beyond the magnetic field’s reach, thus risking severe damage to the driver. It is possible that a driver whose coil can handle 100 W, once placed in a speaker cabinet, will reach its mechanical limit at around only 10 Watts. Nevertheless, such a limit would only be reached in a specific situation, i.e. with a signal containing extremely low frequencies (< 100 W) and the volume turned up very high.

Vue en coupe d'un haut-parleur

Sectional view of a speaker

Should the amplifier?s power be inferior to the that of the speakers? power handling capacity?

No, and the contrary is actually recommended. First of all, it is important to note that a 2×100 W amplifier does not constantly deliver this amount of power. The power sent to the speakers depends on the sound level adjusted via the volume potentiometer. A low-power amplifier pushed to its limits (with the volume turned way up) can malfunction, sending potentially dangerous signals to the drivers. A 2×100 W amplifier with a 50 W speaker is not an aberration, especially since the 100 W mark is reached only during peaks and the maximum continuous power is more likely to be around 50 W. At this level, the sound volume is already deafening with most speakers.

It is important to note that with 1 Watt of power, most speakers can deliver around 90 dB, which is a substantial level.

Micromega IA-400

[The Micromega IA-400 amplifier, capable of delivering 2×400 W, can also power speakers with a much lower power handling capacity

Which speaker will let you max out the volume?

When produced at a high volume level, low frequencies require the largest amount of power and are mechanically demanding for the drivers. This is why we recommend choosing a speaker equipped with several bass drivers and, if possible, of a large diameter (6″ and above). Floor-standing speakers featuring 8″ drivers such as the Elipson Prestige 4i, JBL ES90, Klipsch Reference R-28F, Wharfedale Diamond 250, Davis Acoustics Dhavani, and Klipsch RF-7 MKII are excellent choices for a powerful listening experience. But, if you would rather acquire compact speakers for esthetic reasons, combining them with a home cinema amplifier and a subwoofer will also allow you to enjoy a high sound level. In such a setup, a home cinema amplifier can transmit the very low frequencies to the subwoofer, thus increasing the speakers? power handling capacity.


This post is also available in: French

About the author

Tristan Jacquel

Tristan est rédacteur chez Son-Vidé Passionné de musique, d'acoustique et de high-tech, il réalise notamment les tests matériels pour notre blog.

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