Speakers vs. rated watts?

[OnlyVees]

I almost feel foolish asking this, but... I've always been told to double the output of an amplifier when choosing a speaker. In otherwords, if the amps puts out 15 watts, then use a speaker rated for 30 watts.

Is there any sense in this? I'm GASing for a Vox AC15CC, and I see the fancy version uses a Celestion Blue Dog speaker rated at 15 watts. How much would the tone change if using the same speaker but one rated at 30 watts?

Thoughts?

[SatelliteAmps]

Some depends on how the speaker is rated. The Celestion Alnico Blue (the Blue Dog is a Weber speaker) can handle an AC15 just fine.

[strat a various]

Different speakers are rated conservatively vs. hopefully; different amps similarly are rated on the high side or the low end. Also, consider that some players find a sweet spot that doesn't stress the speakers with undue distortion or peak transients, others dime the amp AND use boost pedals.
After a few years of experimenting, you get a feel for the limits of certain speakers. I've blown more hefty speakers than wimpy ones, because of their high power ratings. False sense of security, so to speak.

[rockstarjay]

Depends on how much gain you play with. Speakers are rated for CLEAN watts.

Here's the rules of thumb I go by:

speaker power handling (http://www.jayskyler.com/guitar-gear-guide/speaker-power-handling.html)

[SatelliteAmps]

Speakers are rated for how much heat they can take before the voice coil melts at a specific frequency.

Not by clean or distorted watts.

Speaker wattage ratings don't care how much gain you want to use, but purely how many watts you are pushing. The rating system you linked to is more about covering the amp's wattage, not the speaker (and that system is way overkill. It also takes nothing into account for tonality).

[jay42]

Good rules:


If you want clean go with a bit more than the rated power.
If you want breakup/OD use 50% to 100% more power handling. (40-50 watt amp = 60-100 watt power handling)
You play with lots of gain you want 4-5x the rated power.
I think a lot of players don't understand that the "musical content" has a great deal to do with these rules. If you're the blues guy, who's plugged straight in, everthing cools down a bit when you put the spaces in. (think Kenny Blue Ray) If you're playing some kind of constant chugging &/or heavily compressed part, then everthing gets hot and stays that way. (think Sex Pistols)

If you read interviews with the techs who work for some of the pioneers -- Rolling Stones, Eric Clapton, Carlos Santana or even Robben Ford, you'll find them discussing re-coning speakers as a regular part of their job...so I maintain that they don't mind blowing speakers if they're getting the tone they want. Clapton has also used EV-12Ls, which I imagine did not blow that often, or at all.

[Old Tele man]

...just remember, a clean 50W amp can easily produce 100W of ugly (ie: square-wave!) distortion.

[strat a various]

Speakers are rated for how much heat they can take before the voice coil melts at a specific frequency.

Not by clean or distorted watts.

Speaker wattage ratings don't care how much gain you want to use, but purely how many watts you are pushing. The rating system you linked to is more about covering the amp's wattage, not the speaker (and that system is way overkill. It also takes nothing into account for tonality).

It's been my experience, and the experience of every tech and engineer I've ever talked with, that speakers handle distortion with less aplomb than clean tones.

[SatelliteAmps]

It's been my experience, and the experience of every tech and engineer I've ever talked with, that speakers handle distortion with less aplomb than clean tones.

Never heard an engineer or tech say that who knew what they were talking about. A 25 watt speaker can blow with 25 watts clean or 25 watts of distortion. It's still making the same amount of heat. A watt is a watt whether clean or distorted.

I have heard many people not understand that their 25 watt amp is pushing more than 25 watts when it is cranked all the way up. I've heard a few uneducated techs who thought this means that the 25 watts of distortion is harder on a speaker, without considering that it is probably much more than 25 watts.

[plexistack]

I think the confusion comes from the fact that a 22 watt amp might put out 22 watts clean, but has the ability to crank out closer to 35 or 40 watts if master & gain are both cranked. So a 25 watt speaker might be challenged if played at high volume & high gain.

It's not really about clean/gain but amps do tend to put out more watts than rated at when cranked to saturation.

[jay42]

I've heard a few uneducated techs who thought this means that the 25 watts of distortion is harder on a speaker, without considering that it is probably much more than 25 watts.That does hold for PA horns though. Distortion is very hard on them.

[strat a various]

This PDF is directed initially at high powered car audio speakers, but read down a ways, and there are some fascinating facts about square waves, distortion, speaker damage... and addressed therein is the subject of distortion's affect on H.F. drivers (attn jay42). Loads quickly, it's a short file.


http://monstercable.biz/mpc/stable/tech/A2420_Some_Facts.pdf

[GearHeadFred]

That does hold for PA horns though. Distortion is very hard on them.

That's for a different reason.. PA speakers use cross-overs to send the highs to the horn, and the lows to the woofers. When the PA amp starts to clip, it generates a lot of high frequencies, causing the horn to receive more power than it can handle.

Think about it this way. If you crank your tube screamer pedal, but have your amp volume set low, the tone is very distorted, but you're not pushing the speakers (power wise). But when you crank the amp, it distorts, possibly putting out more power than its spec'd for.. That's when speakers can get in trouble if they are only rated for the same wattage as the amp.