So What Are Them WATTS These Days????

[jonfields45]

"50 watt" amps that can run 3 hours on 8 AAs???

"2000 watt" powered speakers in plastic boxes (not great heat radiators) with fans unsuitable for a small PC that ought to get as hot as a space heater at a fraction of that power (speakers are less than 10% efficient even if the electronics are wondrous class D)!!!

"100 VA" wall outlet loads (100 watts peak) powering 250 watt RMS amps???

A 40 watt AER Alpha louder than a 200 watt ZT Lunchbox Acoustic!

I like to throw around that I'm a retired EE whose career drifted into marketing at times, but this is truly flame worthy! I think I could explain all the marketing but I find it amazing they are getting away with it.

[SpruceTop]

Yeah, it seemed the component stereo world kind of got reeled-in on its wattage claims decades ago but the pro-sound audio world seems to be taking wildly inflated liberties with the good old Watt! When is a device's advertised wattage rating based on RMS Watts or Continuous Watts or Peak Watts, and over what bandwidth? It seems a watt is anything the pro-audio world wants it to be when marketing to less-than-knowledgeable buyers.

[Mandobart]

I've talked about the topic on this thread, posts #25 and #30. Don't want to clutter up the forum reposting here. Good topic!

[RayCJ]

Funny you should ask...

A Watt is the rate at which energy is consumed. In simple electronic circuits (either DC or non-varying AC) Watts = Volts x Amps. Watts is a little different than what is sometimes called VA. It has to do with the phase of voltage with respect to the Amperage. With a simple case circuit, VA will equal Watts. Usually though, VA is a little less than Watts.

The problem when it comes to musical or vocal audio is that sound varies in three ways. It is both Amplitude Modulated, Frequency Modulated and furthermore, doesn't even have a steady carrier wave. Given this, it's darn near impossible to multiply the corresponding values of voltage and amperage to come-up with a simple product of Watts.

Yes, the electrical cord to your guitar amplifier (in North America) is about 120V with a carrier of 60Hz and Amperage is limited at the wall outlet with a fuse to around 20A. In all reality, the guitar amp has an internal fuse that is probably 1 Amp. Thus, your amp might have a 100 VA power rating. Given this, one might think the max Wattage of your amp is 100 Watts. -Wrong. The amplifier could (almost certainly does) contain capacitors which store energy. They can give-out tremendous bursts of "Wattage" for short periods of time.

Someone in another thread pointed to some nice links about how various manufacturers and industry standards organizations measure power. They were good explanations and seemed technically accurate. Those would be good references to learn about how some Wattage specifications are derived.

Anyhow, if you truly wanted to measure the Watt output of your speakers, you would need to do some form of calorimeter testing. Basically, you would need to play the speakers in scientifically closed/sealed room then, measure temperature differences in the air surrounding the speakers. Similar techniques are used for high-power, ultrasonic transducers used for internal or prenatal imaging.

Ray

[Mandobart]

Not quite Ray. VA and VARs only apply to AC, and VA can never be less than watts in a given source or load configuration. For those that haven't spent their careers making electricity, VA stands for "volt-amperes." Power is a vector - it is the cross product of the across variable (voltage) and the through variable (current). Since it is a vector cross product it has three components that form a right triangle. When plotted the horizontal component is true power, expressed in Watts. This is consumed by the resistive elements of a load, usually dissipated as heat. The vertical component of power is reactive power, expressed as volt-amperes reactive or VAR. This is the power used by reactive components (inductive or capacitive). These loads are expressed in impedance, since the reactance varies with the frequency. Reactive load is a big deal on the grid and for a power station. The hypotenuse of this triangle is called apparent power and is expressed in VA. It is the largest component of the power triangle - there is no way a load can draw more true power (watts) than apparent power (VA). Any capacitive or inductive reactance effects will impact the VARs but not the Watts.

[MikeB1]

Thanks Jon, Ray, Mando, and SpruceTop for your comments. You all, obviously have significant expertise in this field.

My main point for asking this question in the “Best Amp Under $500” thread was to try to determine if two amps in the same price category could be in the same quality category when they have such large differences in specifications, such as a 50 watt amp (Schertler Guilia Y, $499, 14 lbs.) vs. a 250 watt amp (Carvin Ag200, $429, 26 lbs. Note: The Carvin video says the 200 watts goes up to 250 when you connect an extension speaker).

As a lay person, I would expect that the 50 watt amp will not be as loud, but I was wondering if it was possible for it to have the same quality tone as a 250 watt amp. This would make the 50 watt amp fine for someone playing smaller rooms who doesn’t need the volume, but doesn’t want to sacrifice tone quality.

How does wattage relate to quality of tone? From what I am getting from you guys so far, you can’t determine if these amps are in the same quality category because these manufacturers may be using the term “watt” to convey different meanings.

I always found it counter-intuitive when a company says an amp is 100 watts, but when you add an external speaker, it is 200 watts. It always seemed logical to me that the wattage would decrease by half since the amp now has to drive double the speakers. But again, from what I get from you guys, I will have to study quite a bit to get an understanding of all the meanings for the “W” word.

And what can we deduce from all that extra weight? The Carvin is almost double the weight of the Schertler. What kind of extra stuff (sorry to use technical terms) could be in the Carvin?

Jon, thanks for the response about Django Book’s assessment of the Schertler.

I never see these amps in stores so all I have to go on is these descriptions and the great information that you guys so graciously share.

Thanks so much for the education!!!

[Bobby1note]

Should call them "WHATS".



Efficiency, only seems to "sell" to a limited crowd.

[RayCJ]

Originally Posted by MikeB1

And what can we deduce from all that extra weight? The Carvin is almost double the weight of the Schertler. What kind of extra stuff (sorry to use technical terms) could be in the Carvin?

Jon, thanks for the response about Django Book’s assessment of the Schertler.

!

The extra weight is for a few reasons. It could be made of thicker, heavier building materials to withstand bouncing around during regular transportation from gig-to-gig. Heavier stuff won't rattle and if it's glued and screwed together well, it won't squeak either.

As for the amplifier head, the tube-based versions use "old time" AC to DC converters consisting of traditional soft, iron core transformers and a couple (sometimes four) HUGE capacitors. It's those mongo-sized capacitors that can hold a great deal of energy for peak times when the thing needs to crank-out the Watts. Those transformers can weigh 10-15 lbs and the caps can weigh a couple pounds each. A solid-state (semiconductor) device would weigh a few ounces (if that much).

I'm not the right person to tell you how the music industry is rating Wattage these days. -They're full of cr@p as far as I can tell.

My advice, get the one that's in your price range, sounds the best, has a good warranty -and make sure you're able to pick it up and carry it


Ray

[martingitdave]

Originally Posted by jonfields45

"50 watt" amps that can run 3 hours on 8 AAs???

"2000 watt" powered speakers in plastic boxes (not great heat radiators) with fans unsuitable for a small PC that ought to get as hot as a space heater at a fraction of that power (speakers are less than 10% efficient even if the electronics are wondrous class D)!!!

"100 VA" wall outlet loads (100 watts peak) powering 250 watt RMS amps???

A 40 watt AER Alpha louder than a 200 watt ZT Lunchbox Acoustic!

I like to throw around that I'm a retired EE whose career drifted into marketing at times, but this is truly flame worthy! I think I could explain all the marketing but I find it amazing they are getting away with it.

I'm an engineer too. I chuckle when I read some of the marketing claims for consumer and home improvememt products. Of course, wattage is less important the the actual SPL and frequency response. That's another topic that confuses people. Fortunately, most of the gear out there does what it needs to do regardless of the marketing.

Sent from my SM-G930V using Tapatalk

[jseth]

Yes, watts "ain't what they used to be", apparently! I don't know exactly when the free-for-all started, but I miss the days of a watts rating RMS @8 ohms, THD <.005%... where you had a clue at least, of what the piece of gear ACTUALLY produced...

Of course, how that power is then "mated" to speakers is a huge variable, as well...

I have an AER Compact 60/2... ONE 8" speaker... 60 solid state watts... and the thing is INCREDIBLY loud and clean! I have used this to both sing and play through in a fairly large room, and have never had the master volume up to half-way, not even close...

A good part of hearing this amp still has me just shaking my head and laughing at how in the world those engineers at AER got this kind of power and performance out of this little box...

[Mandobart]

Originally Posted by MikeB1

... to try to determine if two amps in the same price category could be in the same quality category when they have such large differences in specifications, such as a 50 watt amp (Schertler Guilia Y, $499, 14 lbs.) vs. a 250 watt amp (Carvin Ag200, $429, 26 lbs. Note: The Carvin video says the 200 watts goes up to 250 when you connect an extension speaker).

How does wattage relate to quality of tone? From what I am getting from you guys so far, you can’t determine if these amps are in the same quality category because these manufacturers may be using the term “watt” to convey different meanings.

I always found it counter-intuitive when a company says an amp is 100 watts, but when you add an external speaker, it is 200 watts. It always seemed logical to me that the wattage would decrease by half since the amp now has to drive double the speakers. But again, from what I get from you guys, I will have to study quite a bit to get an understanding of all the meanings for the “W” word.

And what can we deduce from all that extra weight? The Carvin is almost double the weight of the Schertler. What kind of extra stuff (sorry to use technical terms) could be in the Carvin?

The power rating is the most confusing part - we'll address that first. There are two things we really care about: the power the amplifier produces and the power the speakers can handle. The 200 W for single cabinet and 250 W with extension has to refer to what the speakers can handle (sometimes termed "program power"). No they don't come out and say that - I am assuming that based on other specs such as the 100 VA input. It should be intuitive that as you add speakers you add power handling capability. However you cannot raise the ultimate power the amp can produce by adding speakers.

I would not infer anything about tonal quality based on stated VA, RMS power or program power.

Transformers and speakers are the heavy electrical components in solid state amps. In a multi-amped amplifier or powered speaker you add weight as you go from one to bi-amped to more. Also the Carvin has a full three channels with two separate inputs on the two main channels. Add built in effects, a phantom power supply, a power supply for USB charging port, etc. and the weight adds up. The other components from a weight perspective are the actual construction materials - cabinet, grille, etc. At about 30 lbs its not too bad. I have a folding heavy duty cart to load everything on.

[SpruceTop]

Hey, this is great having some engineers adding their expertise and opinions to this discussion!

Okay, we've seen some power ratings of 2000 watts for some of the active PA speakers. These are usually bi-amped with one amp supplying power to the woofer section and another to the mid-range-/treble-frequency speaker or horn-loaded compression-driver. Obviously, this is misleading as in the case, for example, of QSC and their K Series speakers with their 1000 watt ratings, These active PA speakers have one 500-watt amp for the woofer and one 500-watt amp for the horn-loaded compression-driver section. These 500-watt ratings are peak watts, I think, and I'm sure both the amps are capable of supplying those wattage ratings to each section of the speaker. Let's face it folks, I don't think they're actually allowing the mid-range/treble-frequency amp to run to its maximum peak wattage rating as it would likely blow the diaphragm in the compression driver. I'd assume QSC has DSP limiting applied to the mid-range-/treble-frequency amp to regulate its output to a saner, perhaps, 50-watt maximum?

[RayCJ]

Originally Posted by MikeB1

As a lay person, I would expect that the 50 watt amp will not be as loud, but I was wondering if it was possible for it to have the same quality tone as a 250 watt amp. This would make the 50 watt amp fine for someone playing smaller rooms who doesn’t need the volume, but doesn’t want to sacrifice tone quality.

How does wattage relate to quality of tone? From what I am getting from you guys so far, you can’t determine if these amps are in the same quality category because these manufacturers may be using the term “watt” to convey different meanings.

A 50 Watt amp may, or may not, be louder than a 250 Watt amp... Depends on the configuration of amp. Amplifiers are categorized in classes. A "Class A" is barely 15-20% efficient whereas class B, C or various hybrids can be 4 times as efficient. The classic "Class A" amp is powered with a vacuum tube. They're highly linear, very low distortion. There's a reason people are paying big money for old fashioned tube amps... They kick butt (-and they're cool looking). Also, loudness (SPL: Sound Pressure Level) depends on the speaker too. Some speakers produce more bang for a given amount of power.

Tone quality... Now here's a big topic. Let's just say that some amplifier/speaker combinations have a sweet-spot range where the tone is most pleasing to most people over a given range of amplification levels. Tone depends a lot on the speaker itself, the class of amplifier (different classes of amplifier produce different harmonic distortions) the enclosure/cabinet and placement in the room. Very complicated topic.

I hate to say this but, there's no magic numbers or specifications you can look for in an amplifier to determine how good/loud it will sound.

EDIT: If the volume button goes up to 11, it will go louder than the cheaper model that only goes up to 10. -That, you can take to the bank...

Ray

[RayCJ]

Originally Posted by SpruceTop

Hey, this is great having some engineers adding their expertise and opinions to this discussion!

Okay, we've seen some power ratings of 2000 watts for some of the active PA speakers. These are usually bi-amped with one amp supplying power to the woofer section and another to the mid-range-/treble-frequency speaker or horn-loaded compression-driver. Obviously, this is misleading as in the case, for example, of QSC and their K Series speakers with their 1000 watt ratings, These active PA speakers have one 500-watt amp for the woofer and one 500-watt amp for the horn-loaded compression-driver section. These 500-watt ratings are peak watts, I think, and I'm sure both the amps are capable of supplying those wattage ratings to each section of the speaker. Let's face it folks, I don't think they're actually allowing the mid-range/treble-frequency amp to run to its maximum peak wattage rating as it would likely blow the diaphragm in the compression driver. I'd assume QSC has DSP limiting applied to the mid-range-/treble-frequency amp to regulate its output to a saner, perhaps, 50-watt maximum?

If 2000 Watts were purely converted to audio energy say at a 1000 Hz tone, it would be physically harmful at close distances (not kidding either). I don't think any speaker in the world could handle it for more than a fraction of a second.

Those peak Watt ratings are for very brief periods of time. You can put your finger on frying pan for a split second without getting a blister... -Just don't hold it there for more than a split second. At really, really high power ratings... think about if you have a glowing red hot piece of metal. If you put your fingertip on it for a split second, you will instantly regret it (i.e. blown speaker).


Ray

[SpruceTop]

Maybe the electrical engineers will chime in on this tongue-in-cheek scenario? I'm assuming with the right design, engineering and high-capacity capacitors, amps capable of super-high, peak-wattage ratings are possible. If so, how long will it be before amp companies start upping the ante in the watt wars for our dollars by offering audio amps advertised with 5,000- or 10,000-watt ratings aimed at giggers? Is it possible to do this while keeping the weight and cost reasonable for amps with these high peak-wattage ratings? I'm thinking amps of this power would likely trip a breaker in a typical 120-volt, 15- to 20-amp line if driven even moderately, wouldn't they? Although impractical and unnecessary for most of us, amps with these high wattage ratings could be used as a marketing tool to lure buyers to a company's products; if one company comes up with a product with these ratings, others will follow! Any thoughts on the possibility of something like this happening?