What does the power rating of a loudspeaker mean?

[yeoshiki]

Hi all. I am an amature in audio. I recently bought a speaker which was rated at 30W. Can anyone help to explain what this rating actually means? From this information can we know what is the maximum voltage and current that can be used to drive the loudspeaker without damaging it? Also, Can a power amplifier with a rating of greater than 30W be used?

[Cyrus_s]

Originally posted by yeoshiki
Hi all. I am an amature in audio. I recently bought a speaker which was rated at 30W. Can anyone help to explain what this rating actually means? From this information can we know what is the maximum voltage and current that can be used to drive the loudspeaker without damaging it? Also, Can a power amplifier with a rating of greater than 30W be used?

IMO It depends on what you will use it for and how the manufacturer rates its drivers.

The designed alignment will dicatate your power ratings, you may come to mechanical limitations long before thermal limitations or vice versa.

Some manufacturers have questionable specifications. Take that how you will.

[AndrewT]

Hi,
there are many different ways to specify the maximum power that a speaker can survive.

Most speaker manufacturers will try to use the method that makes their equipment seem better than their competitiors.

Fo all these reasons you cannot rely on the quoted power handling. It is a very loose guide only.

Your ears are by far the best tool for assessing overdrive.

The speaker is more likely to be damaged by overdriving the amplifier. To avoid this basic problem I suggest you use a bigger amp and make sure your ears tell you that you are NOT overdriving the speaker. This way you avoid amp clipping and overdrive distortion.

The end result is the music sounds good and the speakers last forever.

[myhrrhleine]

Hi,

Speaker power rating is often the voice coil thermal rating.

[rabbitz]

.... or where it runs out of xmax.... thud.

[clem_o]

Originally posted by AndrewT

Your ears are by far the best tool for assessing overdrive.

The speaker is more likely to be damaged by overdriving the amplifier. To avoid this basic problem I suggest you use a bigger amp and make sure your ears tell you that you are NOT overdriving the speaker. This way you avoid amp clipping and overdrive distortion.

Hi AndrewT,

Most of the time, that's "sound" advice. But, I do remember several years ago we actually blew a bass driver (a sansui, i think) in a similar situation, i.e. sounding good with a power amp rated for maybe 2x the loudspeaker rating. Apparently the enclosure / driver combination resulted in an acoustic power rating greater than the driver's thermal capacity... Well, it was a bass reflex box, and we had the "rumble filter" on.

Just an fyi...

Cheers!

Clem