Speakers and "musical power"

[Ptron]

I was looking at some specs for Jensen speakers and noticed they have one for "musical power." Is this what I used to see referred to as "peak power" or is it some new, supposedly more relevant spec?

Anyone wanna take a stab at telling me what "musical power" really means and how it does or doesn't apply to the world of guitar amp speakers?

Sorry if I'm opening up a can of worms here. I realize the world of manufacturer specs is murky, esp when it comes to power.

BTW, if this is a marketing thing, isn't it very unwise of a speaker company to tempt folks into putting a 25W speaker in a 50W amp beacuse the spec sheet says it can handle 50W of "musical power"? Folks might tend get down on a speaker that melts down halfway through thier first gig.

[tbryanh]

It appears your guess that “musical power” is the same as “peak power” is correct.

The nominal power rating of the Jensen speaker is half of the musical power rating of the speaker.

This coincides with amplifier power ratings. A 100 watt amp puts out a maximum of 100 watts of clean power, but it can put out 200 watts of distorted power.

Amplifiers are generally rated according to the amount of clean power they can put out. Before rock and roll, amps were intended to be played clean, so a tradition of rating the maximum amount of clean power was established before rock and roll and continues today.

For most situations, to match the speaker to the amp, match the nominal rating of the speaker to the power rating of the amp.

If you do not distort the amp, the amp and speaker should last a long time, but then your no rocking and rolling. If you want to rock and roll, plan on plenty of crashing and burning.

[Ptron]

Thanks tbryanh. That's what I was looking for.

That changes my thinking on speaker ratings a bit, actually. I thought that you wanted a speaker to be rated significantly (maybe 1-1/2 to 2 times) higher than the rated output of the amp because of the greater output the amp can have when distorted. Sounds like theoretically, a speaker matched to the rated output, with peak/musical power handling of double that, would squeak by and the rest is insurance.

[Rob Mercure]

While I think TB is essentially correct years ago this issue was finally settled, as best I know, but the Federal Trade Commission concerning claims of "peak" power being sometimes 10X the RMS dissipation. And this is the primary reason that the term "peak" has disappeared. Which makes me wonder if there is a "legal" definition for "music" power. Ptron, I'll assume that you've done a google/etc., search for the term? I hope so cuz we may be a bunch of techs trying to wrestle with a legally defined marketing term and I for one still remain cautious about making my speaker decisions based on ill defined terminology. If you're dealing with new speakers then take a look at the impedance vs. frequency charts - at your lowest impedance, assuming that the amplifier produced a constant output with frequency (big assumption) the speaker will have to dissipate much more power. If this is way outside "normal" guitar frequencies then - such as 10 kHz, or 55 Hz, then you've got some extra dissipation margins. If it's 400 Hz then you might want to go the "overkill" route. If the amplifier is for your own use and you're playing lotsa heavily distorted "power chords" then you'll need more capacity for the same amplifier output than if you're amplifying an acoustic guitar and tend to move around the neck frequently.

"For every complex problem there's a simple solution - that's wrong!"

Rob

[Enzo]

Music power is largely a marketing tool. I don't know if a real definition even exists. It is generally twice the real power output of the amp.

50 watts of music is not at all like 50 watts of sine wave. A sine wave will test the full power capability of a speaker. Music however is generally a series of brief pulses - drum hits - interspersed with much lower amplitude stuff. SO when an amp is putting out "50 watts," it is really putting out 50 watt spikes with the rest much lower, so the average power might only be 20 watts.

So I can connect a 50 watt amp to a 25 watt speaker and play it pretty loud safely, as long as it is music. But if I start listening to sine waves, then I better turn it down.

Straight noise is also a full test of a speaker, as it is full amplitude at all freqs.