News

The FTC Updates the "Amplifier Rule"

John Atkinson  |  Sep 10, 2024

At the end of 2020, the Federal Trade Commission proposed eliminating what had come to be known as the "Amplifier Rule," which had been in effect since 1974. Then-FTC commissioner Christine S. Wilson wrote, "Freeing businesses from unnecessarily prescriptive requirements benefits consumers."

To me, that made no sense. Far from imposing "unnecessarily prescriptive requirements" on amplifier manufacturers, the Amplifier Rule had long forced manufacturers to clean up their acts.

As I wrote in an article published on the Stereophile website in 2021, in the hi-fi boom that began in the 1960s, the Institute of High Fidelity became alarmed by amplifier manufacturers exaggerating their products' output power. Such mystical numbers as "Peak Power" and "Music Power" were used willy-nilly to produce sales-oriented ratings with little to do with reality (footnote 1). The IHF's proposed standard was examined in a paper presented at a 1967 Audio Engineering Society convention by Daniel von Recklinghausen, then with manufacturer H.H. Scott, and reprinted in the Journal of the Audio Engineering Society in July 1968. The IHF proposal resulted in much discussion in audio engineering circles, and in 1974, following open hearings, the FTC published its first Amplifier Rule. The purpose was to impose uniform, conservative standards on how domestic amplifier powers were rated and advertised.

The original Amplifier Rule was revised in 2000, imposing the following conditions on manufacturers:

• Power output was to be expressed as "average continuous power in watts."

• Load impedance should be 8 ohms.

• All associated channels must be driven while the measurement was made. (This requirement was later dropped for multi-channel home-theater amplifiers, where only the main L and R channels needed to be driven.)

• The power bandwidth or power frequency response must be cited.

• The maximum THD from 0.25W to the rated power must be cited.

• The amplifier must be preconditioned with a 1kHz sinewave at 1/8 rated power for 60 minutes before measuring. This was a revision from the original requirement, which mandated preconditioning at 1/3 power, a level that results in the maximum heat dissipation in a class-AB amplifier's output devices, for 60 minutes. Concerned about the impact of the original rule on multichannel home-theater amplifiers, the Consumer Electronics Association (CEA) changed the preconditioning time from one hour to 30 minutes in its own standard (CEA-490-A). The FTC adopted the 30 minutes requirement in 2008.

The FTC invited public comments for those concerned about the effect of eliminating the Amplifier Rule. Some 550 people responded. One of those comments, submitted by Ralph Karsten, the founder of amplifier manufacturer Atma-Sphere and for many years the main man there, summed up my own feelings: "Back in 1974 when this rule was enacted it transformed the Wild West of amplifier sales to an even playing field. It makes no sense to stop now." I made a similar point in a telephone conversation with the FTC's Jock K. Chung in May 2021, in which I described amplifier power testing in detail.

After evaluating the comments received, in July 2022 the commission issued a notice of proposed rulemaking and sought additional comments about its proposals (footnote 2), which would standardize certain test conditions for measuring amplifier power output, and on the parameters of consumers' normal use of multichannel home theater amplifiers. Then, in July 2023, the agency issued a supplemental notice of proposed rulemaking (SNPRM) for comment. Finally, in July 2024, the FTC published what it called the "Final Amendments to Amplifier Rule to Make Testing Methods More Useful to Consumers."

The new rule does not require amplifier manufacturers to disclose maximum power output—but those that do must follow the new standards. The revisions are listed in a pdf entitled "Part 432—Power Output Claims for Amplifiers Utilized in Home Entertainment Products." The preconditioning period is specified: 1/8 power with an 8 ohm load for one hour. In a stereo amplifier, both channels must be driven. Most significantly, after the input signal has been continuously applied at full rated power for at least five minutes, the amplifier needs to be able to operate "at any power level from 250mW to the rated power at all frequencies within the rated power band of 20Hz to 20kHz without exceeding 1.0% of total harmonic distortion plus noise (THD+N) at an impedance of 8 ohms." In simplest terms, the maximum rated power is that at which the amplifier's output does not exceed 1% at any audioband frequency.

As a practical matter, for most amplifiers, maximum output power will be determined by a 20kHz power measurement instead of a 1kHz measurement.

In a typical amplifier circuit, the open-loop bandwidth—the bandwidth before negative feedback is applied—can be as low as a few hundred Hz (footnote 3). The amount of corrective feedback available gets smaller as the frequency rises, so at 1% THD+N an amplifier is likely to deliver a lower maximum power—often much lower—at 20kHz than it is capable of delivering at low and middle frequencies.

Manufacturers that continue to report maximum power output must comply with this new rule, and the new specification must be presented prominently. The manufacturer may, in addition, present power measurements that do not comply with the Amplifier Rule, but such specifications must be accompanied with, "This rating does not meet the FTC standard."

The new Amplifier Rule took effect in August 2024—about the time this issue was going to press (though it may take a while for manufacturers to adjust their specifications). Traditionally, Stereophile has measured maximum output power at 1% THD+N at 1kHz. Going forward, to accord with the new FTC standard, we will add measurements at 20Hz and 20kHz into 8 ohms.

Props to the FTC for not only keeping the Amplifier Rule but even making it tougher.

Footnote 1: I gave an example of this exaggeration in an article I wrote in 1989 in which I both discussed the FTC's Amplifier Rule and announced that Stereophile was to include measurements in its reviews. "Running from, say, a 14V car supply, a typical single-ended amplifier can swing around 12V peak–peak into a 4-ohm loudspeaker. This voltage is equivalent to an RMS voltage of 12/(2×root 2) = 4.24V RMS. This is the DC voltage equivalent to that peak-peak AC voltage when considered as a source for resistive heating. By Ohm's Law, into a 4-ohm load, that 4.24 RMS voltage will raise 4.24×4.24/4 W, ie, just 4.5W! I know, I know, you're not going to sell many 4.5W amplifiers come crank-it-up season, so let's use the power that would be generated if that peak-peak voltage were, instead, an RMS figure . . . That gives, let's think up a fancy label, a "Maximum Peak Burst Power" rating, for example—no, replace the word "Burst," it implies that the amp can't keep it up—a "Maximum Peak Music Power" of 36W!"

Footnote 2: One of those comments included several references to Stereophile's amplifier measurements.

Footnote 3: See fig.3 here.

COMMENTS
cognoscente's picture
Submitted by cognoscente on September 10, 2024 - 7:08am

Rules are generally there to regulate social intercourse. On an abstract level it is a philosophical question: is a rule useful and for whom actually? That should be the question, not the issue itself.

cognoscente's picture
Submitted by cognoscente on September 10, 2024 - 7:12am

what I mean is, who benefits (the most) from the rule, then you understand where the rule comes from (and whether you want to stick to it or not)

MT_Guy723's picture
Submitted by MT_Guy723 on September 12, 2024 - 12:22pm

The consumer primarily... once he's familiar with, say, what a 100 watt amplifier actually puts out for power - compared to a different amp with the same power rating.

As it is now, such a thing as "Marketing Watts" exist and various components are advertised with more power level than they actually deliver. Standardizing the measurements and resulting specs that are published should be a very good thing for all concerned.

David Harper's picture
Submitted by David Harper on September 10, 2024 - 7:57am

The rule was a good one in that the intent was to prevent companies from essentially lying about the output power of an amplifier. The reasoning behind eliminating it is to enable the sellers of gear to profiteer more effectively at the expense of the uninformed consumer.

jimtavegia's picture
Submitted by jimtavegia on September 10, 2024 - 8:15am

Big government has looked out for the consumer, but no industry has been hurt more by them than the auto industry. Their regulations and mandates have saved some lives, but also driven up the cost of a car and has them to the point that the shade tree mechanic who loved to fix his own car has nearly come to an end.

I know metal dashboards were bad, but my grandfather installed his own seatbelts and turn-signals in his cars from kits from Western Auto. You could be as safe as you wanted to be.

Anyone could easily tune up their car with new spark plugs, a set of points and a condenser. Timing light sales were strong. Air filters were the easiest of all. No frosty head lights as you changed out the whole glass sealed beam and then aligned them. It is more fun now with the cars that nearly blind you when coming your way with the new light technology.

I even over-hauled my step-dad's 1960 180b Mercedes and ground the valves my hand, had a new valve guide installed that was the same spec as one from a Pontiac Tempest, and took out a few links from the bicycle-style timing chain. New piston rings, and bearings helped finish the job. We had turned the speedometer over 2 times so it was time. I learned a lot from that experience.

And yet we have so many accidents now with people who are just careless, and some bordering on suicidal. Go figure.

I bought my first car, a '69 429 Mustang for all of $3K, Now they are more than any of my first 3 houses. I guess that is progress.

mrstuffy's picture
Submitted by mrstuffy on September 10, 2024 - 9:19am

Using 1969 (your first Mustang) and 2022 (most recent data) as references, the death rate per 100,000,000 vehicle miles for cars has fallen from 5.2 to 1.3, or 75%. Given that there were still over 46,000 traffic related deaths in 2022, that means those regulations that have made cars more expensive are also saving nearly 150,000 lives every single year. Car maintenance might be more expensive than it was and it requires special tools, but it's very hard to argue that saving that many lives every single year isn't worth it.

cognoscente's picture
Submitted by cognoscente on September 10, 2024 - 10:11am

Somewhere in the late sixties / early seventies there was a US car model on the market of which the manufacturer knew soon after introduction how dangerous the design was, the petrol tank could easily catch fire and explode. They then calculated how much it would cost to recall all models sold and to adapt the model of cars yet to be produced and sold, or the compensation for deaths due to this defect. The latter turned out to be cheaper and the manufacturer kept quiet and sold the model for years, resulting in deaths.

And what do we think of 2008?

So some kind of rules is certainly good. In this case with amplifiers you can indeed wonder ...

jimtavegia's picture
Submitted by jimtavegia on September 10, 2024 - 10:36am

Not considering all the 100,000' of recalls going on now and every year. What you don't know is the health condition of those 150,000 as a result of those accidents and it is reported that over 25% are driving without insurance. Plus there were only 202 million people in 1969.

Unless you break down the accidents by make of car and by model year can you say what the cost of progress really is. There are a lot of older cars on the roads in questionable repair. It is also telling me that too many are not driving well, defensively, or caring about their own safety or that of others. Plus driving around any of our major cities is much more dangerous than ever with so many on the roads. Tail-gating is a way of life today. People are way more careless today than they used to be.

In 2022, there were approximately 42,915 motor vehicle traffic crash fatalities in the United States, which is a 10.5% increase from the previous year1. Car crashes are the leading cause of death in the United States.

mrstuffy's picture
Submitted by mrstuffy on September 10, 2024 - 11:51am

The 150,000 wouldn't be the accident rate, that would be the number of additional deaths per year if the fatality rate was the same in 2022 as 1969 per mile driven because cars didn't get safety updates, many of which were mandated by federal law. If the drivers have insurance or not has no impact on if they survive a wreck.

If you were to break it down by make and model because "There are a lot of older cars on the roads in questionable repair" then it would likely make cars with safety features look even better, because they account for the majority of cars on the road but those still riding in older cars are more likely to die in accidents because they don't have the safety features that are required by regulations. If drivers today are also worse and more distracted, that speaks even better to cars because more people are surviving accidents due to better cars. Again, those statistics of 150,000 per year are not accidents, but deaths.

Car crashes are the leading cause of death, but as shown by the data the number of deaths per mile driven is 75% lower now than in 1969, showing the regulations have managed to make it far safer than ever.

supamark's picture
Submitted by supamark on September 10, 2024 - 12:02pm

Rules are always a response, especially when those rules are actually consumer safety laws. Cars were death traps, and it's not just about the lives saved (and their contributions to GDP, etc) but also about the societal costs of caring for all the brain injured veggies and para/quadraplegics which is many many $billions. That's you and me paying for a lot of strangers' health care via Medicare/aid.

As someone else said, those cars were pieces of deadly crap built so poorly they had panel gaps big enough to lose your child in. Now only Tesla fits that bill (they kill emergency responders at an alarming rate and their poorly fit body parts have a tendency to fall off or are held on by like literal duct tape).

I'm surprised after Anton Yelchin (Chekov in new Star Trek movies) was killed by his own Jeep in his driveway that a sensor wasn't required in the driver's seat for the car to move (i.e. no driver's butt in the seat, no go). We have them for child car seats already... It was known issue with Jeeps, which are terrible vehicles even today (like everything Stellantis touches). It would also have saved a friend of mine from spending the last 9 months on a ventalator (just got off it!) and being paralyzed from the waist down (not Jeep related). Medicare (so all of us) are paying that huge bill - 9 months in ICU = $big. It also results in funny YouTube videos of people getting out of their cars while still in drive, not park/neutral; but that's not worth lives lost or money it costs.

On article topic, this should result in some interesting power numbers and hopefully some very interesting engineering.

David Harper's picture
Submitted by David Harper on September 10, 2024 - 10:13am

Those old cars that you reference were garbage compared to the new cars of today.

DaveinSM's picture
Submitted by DaveinSM on September 10, 2024 - 4:10pm

Yeah, well those old cars were incredibly inefficient when it came to fuel consumption, as well as having much, MUCH higher pollutant emissions at the tailpipe.

New cars are faster, more powerful, and much cleaner, and I’m not even talking about EVs. All that performance comes at the cost of refinement and complexity. Lighter weight also has been achieved by better, more efficient packaging and higher tech materials. This has allowed auto makers to incorporate many more safety systems besides just seatbelts. Airbags, ABS, side crash protection and rollover protection, etc, etc. so new cars are much much safer than vintage ones, and you’re far less likely to die in one.

Finally, they’ve managed to do all this while making them overall much more reliable. While simplicity is often the key, I defy you to find a late model Toyota, Lexus, or Honda that isn’t basically bulletproof.

All this refinement and complexity comes at the cost of complexity and expense. You are right in that most modern cars are too complex for a non mechanic to work on themselves. And maintaining them when they do need to be fixed is generally more expensive.

But you never saw cars with 10,000 mile service intervals, nor did you ever get the sort of warranties that are routine now.

As a transportation device, autos are inarguably more efficient and reliable than they ever were. Modern ICE cars are the product of decades of refinement and technological advancement.

CG's picture
Submitted by CG on September 11, 2024 - 11:02am

Funny that should bring this up.

Two days ago, I was at the gas station filling up. The price of regular gasoline was $3.28 per gallon at that station. When I got home, I saw that AAA says that is the going rate this week in these parts.

Since everybody seems to be complaining about the price of gas, I got curious and looked up what gas cost in 1968. I was a kid then, and remember my Mom complaining about the price then. According to government statistics from that year, the average price was 35 cents per gallon then, in 1968 dollars. This was before various oil embargoes and market craziness.

Guess what! If you put $3.28 into one of the online inflation calculators and convert that amount to 1968 dollars, the result is 36 cents. Just about the same as today when you account for inflation.

But, as you also point out, cars were generally less efficient then. In fact, the average fuel economy in 1968 for passenger cars was just around 12 miles to the gallon. Today, it's just about double that.

So, that means that the effective cost of fuel per mile travelled is now half of what it was in 1968. In inflated 1968 dollars, that means that you are paying the equivalent of $1.64 per gallon. Or, in 1968 dollars, 18 cents.

But, wait!

If you have a higher efficiency car today, you might get just about double the fuel mileage per gallon compared to the average car. That means that you (OK - I) pay the equivalent of 82 cents per gallon.

Yes, that comes at the cost of higher maintenance fees and so on. I suspect a lot of that would also track inflation. But, since maintenance intervals are far different than in 1968 and more aspects of a car's technicals are checked now, I can't really place an equivalent number comparing 1968 maintenance to 2024.

jimtavegia's picture
Submitted by jimtavegia on September 14, 2024 - 7:21am

Just recalled 150K cars with brake issues. 2 car companies have to have long warranties just to get people to look at them and they can't even get paint to stick to their car bodies.

All your safety features in a car are no match for a head on with an F250 or 2500 Chevy truck.

The new Chevy BelAir starts a $40K from being an affordable car back in the day. I just had the touch screen of my new car replaced $2500 if it was not under warranty. Recalls of cars are in the papers daily due to parts from the lowest bidder. But have it your way. quality on just about everything is out the window in 2024.

DaveinSM's picture
Submitted by DaveinSM on September 14, 2024 - 7:59am

You do realize BMW sold more than 100,000 cars in the 4th quarter of last year alone, right?

The number of BMWs out on the road is many multiples of what it was in the 70’s and 80’s. Back in the old days, they wouldn’t even issue a recall; they’d let the owners deal with it until they were hit with a class action lawsuit.

You conveniently forget Detroit’s planned obsolescence of parts strategy that effectively destroyed American cars’ reputation and competitiveness in the marketplace.. The cars they made back then were absolute piles of garbage, ESPECIALLY compared to modern cars.

Since 1997 I’ve had 4 BMWs, 3 Audis, 2 Volkswagens and a Porsche. All of them were driven pretty much daily, and the only car that ever had any problems was a 2000 Audi A6 2.7t that had a faulty fuel tank indicator replaced under warranty.

Even the 2023 Porsche has a 10,000 mile service interval. It also gets 26-28 mpg on the highway and is as fast as super cars were 10 years ago. JD Power reliability ratings lead me to expect it to be much more reliable than a supercar, too.

Just like with tech, I will concede that there is always a push to sell more new cars, and the new model refresh cycle is relentless. But consumers have long chosen to vote with their feet, and nowadays pretty much expect their cars to be safe and reliable at a level unheard of in the 60s and 70s. That’s why the used car market is so robust.

Your statement on quality when it comes to modern autos is simply out of touch with reality.

supamark's picture
Submitted by supamark on September 17, 2024 - 11:29am

My 4,500 pound 2018 BMW 540i actually is a match for those trucks. The A pillar is bigger than my arm, the B pillar is like 8 inches across. It's a BIG car with a very long hood to fit the inline 6 engine. Educate yourself before you make comments, you're of an age when you should already know that. It will also out accelerate, out handle, and be much more pleasureable to drive than those body on frame POS trucks (30+ mpg on the highway - 2k rpm at 85 mph, under 5 seconds to 60 mph). Oh, and the dealership experience is several orders of magnitude better than you get from non-luxury car companies and BMW is generally top 5 in reliability (70k+ miles and no major issues).

Also, it wasn't part of the original recall but may be part of the larger 1.5 million vehicle recall - possible free brake system upgrade because they're replacing the whole system (current one works great as is - enormous front disks)!

By the way, most of the current recalls are Covid supply chain related - especially Ford but I wouldn't buy any care mfg'd between mid 2020 and the end of 2022. I'm waiting on the 2023's to come off lease to get a 2023 540i (and separately a new M4 with a 6 speed *manual* transmission when my extensive house remodel is done - I miss my manual transmission cars).

zipzimzap's picture
Submitted by zipzimzap on September 11, 2024 - 6:14am

"You could be as safe as you wanted to be."
No you could not. Watch the youtube video called "chevy malibu vs 1959 bel air crash test" and tell me if seatbelts did any good at all for the Bel Air.

MT_Guy723's picture
Submitted by MT_Guy723 on September 12, 2024 - 12:26pm

Mandated seat belts have saved thousands of lives since that law was passed.

While I understand your frustration in this area, your Comment deals with pretty much everything BUT the power delivered by the vehicle's sound system.

Head_Unit's picture
Submitted by Head_Unit on September 13, 2024 - 12:34pm

$3k in 1969 is like $25k today. The $15k I bought a 5.0 for in 1990 is like $36k inflation adjusted. The base price of a 2024 Mustang is $31k, and the car has far more features and better gas mileage. And you don't NEED to $%^# around with points or condensers, you don't change the plugs as often, and I haven't heard of anyone doing anything with valves. Really I hear only very rare cases of people mucking about with the drivetrain at all until mileages far higher than what the "good old days" cars would attain.

Headlights, there I'll agree, to change them on a 2009 Jetta requires bumper removal! And to just change the outside light BULBS requires either a multijointed 8 fingered hand or massive removal. Ugh.

DaveinSM's picture
Submitted by DaveinSM on September 14, 2024 - 8:25am

Those old Fox body 5.0s and GTs were cool cars, and really fast for their time. But sadly, there’s a reason why you don’t see any of them on the road anymore. You see more 60s Mustang restomods out there.

supamark's picture
Submitted by supamark on September 17, 2024 - 12:38pm

A 1983 5.0 with 4 on the floor. Biggest hunk of crap I ever owned, swore off Ford after that one. I had to junk it, which I think speaks directly to your point about there not being many Fox bodies around today.

I owned two different Saab 900 Turbos after that; the second was an '88 SPG, very safe car - it was car #1 in a 9 car pile up that closed the interstate through downtown Austin in '97. I wasn't injured but the car was a couple feet shorter, and very totaled.

supamark's picture
Submitted by supamark on September 10, 2024 - 12:15pm

Power amps should be rated (and built) for 4 Ohm loads instead of 8 - other than some specialty speaker makers like Devore and Audio Note, every modern speaker is a 4 Ohm speaker. The worst part is that when speaker drops below ~2.5 Ohms the damping factor goes out the window and the bass gets not good, unless you use a ton of negative feedback which sounds like crap.

Your output impedence + speaker wire needs to be under 0.05 Ohms to have a decent (more than 50) damping factor into 2 Ohms. A lot of speakers drop into that 2 to 3 Ohm range in the bass. That would be a more useful metric since there's almost no musical info or power above 10kHz.

Glotz's picture
Submitted by Glotz on September 10, 2024 - 1:07pm

And a very real concern with Magneplanar owners or Apogee or ... yeah.

It should be required that figures should be shown on 4 and 2 ohm loads.

zipzimzap's picture
Submitted by zipzimzap on September 11, 2024 - 10:12am

at some point you are overburdening the manufactures to cater to a tiny fraction of the market.

Glotz's picture
Submitted by Glotz on September 11, 2024 - 10:57am

When they perform their normal battery of tests, they can add those 4 ohm and 2 ohm loads as well.

Pretty easy, JA here has been doing it for decades.

The entire industry- including well-known retail brands- would/could do it as per the law in place.

It would help all consumers- including those that shop the typical retail stores.

DaveinSM's picture
Submitted by DaveinSM on September 11, 2024 - 11:26am

I agree here too. Without this info consumers are missing some crucial information on how the amp will perform with demanding speaker loads.

John has tested many of these amps till their output is limited by the AC wall voltage.

supamark's picture
Submitted by supamark on September 11, 2024 - 1:00pm

Pretty much every speaker today spends a considerable amount of time around 4 Ohms, especially below ~500 Hz. Speakers like Devore's that are over 8 Ohms are the actual tiny fraction of the market.

What I don't get is that they do it often in bass reflex speakers with the impedence dropping to like 2 Ohms for an octave or more so that your bass sounds... not good - group delay AND lowering the amplifier damping factor? Sign me up!

Yes, I'm a sealed box guy in a relfex world. Makes me part of the prime stereo (2.2 system) subwoofer demographic. 2.1 is too inaccurate - it throws away some of the bass, the L-R side signal, and only keeps bass that's in both channels and in phase, the L+R mid signal. Mid-side processing is interesting (EQ's and compressors), and goes back to how stereo vinyl records work.

The more you know!

Anton's picture
Submitted by Anton on September 10, 2024 - 4:12pm

Terrific suggestion.

DaveinSM's picture
Submitted by DaveinSM on September 10, 2024 - 4:24pm

That’s what I loved about the early Krell amps. They were rated at only 50-100 watts, but were all business- simple, overbuilt, high current designs. Their power ratings into 4, 2, and even 1 ohm told the real story. I credit them with bringing this aspect of power amp design and ratings into more prominence.

CG's picture
Submitted by CG on September 11, 2024 - 11:23am

Weren't these the amplifiers that were known to catch on fire on occasion, with actual flames being blown out the side of the cabinet by the internal fans? Later models that did this caught the attention of government regulators, who used their extreme abuse of regulatory authority to call the manufacturer on that problem. (Some sarcasm in that last part...) You can look all that up pretty easily.

Being able to continually double output power into very low impedance loads is somewhat over-rated. Unless your loudspeakers have an effective load impedance down to an Ohm or two - and some certainly do - and you run your system at close to clipping levels, you'd never know about the doubling. In a lot of ways, that specification was a misleading marketing tool, too.

Personally, I have measured the power output of our amplifier while playing music pretty loudly into our not really efficient loudspeakers. 15 watts is pretty unappealing to listen to. But, I get that different people have different requirements, which I won't criticize at all.

To be fair, what almost certainly did matter for sound quality in the early Krell amplifiers was the higher level of quiescent current the output stages of the amps were biased to. That gave a much wider power output range for lower distortion Class A operation, which reduced much of the crossover distortion and other not so good sounding effects found in push-pull amplifiers. That was a big step forward.

DaveinSM's picture
Submitted by DaveinSM on September 11, 2024 - 11:30am

I don’t know about that. All you need is a pair of low impedance, low sensitivity speakers in a large room. Pair that with an owner who likes to listen to something like orchestral music at lifelike volumes and I bet you’ll be needing more power into lower impedances than you’d expect.

But yeah, sure- for a lot of us we with real world setups, we have much more power than we typically need.

zipzimzap's picture
Submitted by zipzimzap on September 11, 2024 - 6:24am

They need to regulate speaker specs next. Stop letting companies claim theirs are 8 ohm when they are really 4 or 6. I remember an Andrew Jones interview where he answered about his speaker being 6 ohms and very nicely danced around saying that most manufactures lie about theirs being 8.
And don't even get me started on sensitivity ratings.
I bet a lot of customers pass up speakers with actual higher impedance and higher sensitivity, just because their manufactures are honest about the specs.

Glotz's picture
Submitted by Glotz on September 11, 2024 - 11:13am

I put my suggestion forth.

"Stop letting companies claim theirs..." states the same.

Consumers should know exactly what is up with their amp's power under load.

Thanks tho.

neilgundel's picture
Submitted by neilgundel on September 13, 2024 - 2:04pm

This is all fine, but why insist on full power at 20 kHz?
I guess it makes life easy for the rule makers, but if you ever actually sent full power at 20kHz (or above the tweeter’s crossover frequency for that matter), you’d need new tweeters.

CG's picture
Submitted by CG on September 14, 2024 - 9:25am

Having the tweeters blow would actually be a safety feature. Better blown tweeters than blown ears...

You're right, of course.

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