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Has the FTC Failed Consumer Audio Regarding Amplifier Power Claims? P2


AV Receivers

Onkyo TX-RZ3100Up until the recent explosion of Dolby Atmos in the consumer marketplace, most AV receiver manufacturers were rating power with two channels driven at a specified distortion (usually <0.1% THD+N) at 8-ohms. Only a rare few companies (i.e. NAD) would also specify an "All Channels Driven (ACD)" rating.  However, things seemed to get really mucky once manufacturers stamped Atmos on their receivers and started cramming 9 or more channels into the same sized chassis, with the same sized power supply that their 7-channel predecessors had only a year prior. Instead of getting a 2-channel rating at less than a specified distortion into an 8-ohm impedance, we started seeing something far more dubious.

It started with Onkyo, but others followed suit shortly after.  Instead of rating at 8 ohms, 2 channels driven at a low distortion level, they started rating power with only 1 channel driven, at 6 ohms, at near clipped distortion levels.  The reality of the situation is rating only 1 channel driven isn't very realistic of how a consumer uses an amplifier or receiver since both channels typically draw nearly the same power simultaneously with stereo program material. Also, rating an amplifier at say 0.1% THD+N vs 10% THD+N represents very different behavior of that amplifier. The 0.1% case is arguably an inaudible amount of distortion while the 10% case is not only visible on an Oscilloscope as a clipped wave form but is also very audible. It's at the point where the amplifier can no longer supply additional voltage and instead is turning a sine wave into a square wave with very high audible 2nd order harmonics and potentially damaging signal to the loudspeakers tweeters. Again this is power rated on the vertical trace in the power vs distortion curve previously mentioned.

This allowed the manufacturer to inflate power claims by a good 35-40%, which looks impressive to the uninitiated. More power must be better right? Sadly, most casual shoppers don't realize what's going on and come home with a much less powerful product than they thought they’d purchased.

When the first generation Atmos receivers popped up, some manufacturers were only listing the 1-channel power measurement.  After we called them out on it, they all changed their websites in unison to list both ratings methods (1 channel, 1kHz @ 6 ohms clipped, 2 channels 1kHz per FTC). Though, the FTC states full power bandwidth must be specified, not just one discrete frequency (1kHz).

For an expanded discussion on this topic, read: Power Manipulation in Dolby Atmos AV Receivers

Onkyo TX-RZ3100 & Pioneer SC-LX901

MSRP: $3,099 & $3,000, respectively

 Onkyo Power  Pioneer Spec

Onkyo and Pioneer Both Showcasing inflated 1CH power rating above the 2CH FTC Rating

Denon AVR-X8500H

MSRP: $3,999

Still, some manufacturers are a bit craftier and stamp a power sticker on the front panel of their receivers.  Take for example the new Denon AVR-X8500H 13.2 channel flagship receiver. That 260-watt sticker on the front panel looks impressive. Denon got this magic number by rating only 1 channel driven, at 6-ohms and 10% THD+N (hard clipping).  This is a completely ludicrous way of rating power, similar to peak power rating that FTC Rule 46 CFR 432 warned against. The AVR-X8500H is already a very powerful receiver when honestly rated at 150 watts/ch with 2 channels driven.  It's doubtful most consumers plopping down $4k on an AV receiver wouldn't at least be aware the 260-watt rating is inflated, so why bother if it only serves to cause doubt among your core customers?

Denon AVR-X8500H

Denon AVR-X8500H 13.2CH AV Receiver with 260 watt front panel sticker

Yamaha RX-A3070

MSRP: $1,999

Yamaha does similar with their JEITA power rating (1kHz, 1 channel, 8 ohms, 10% THD), but at least they don't slap a sticker on the front panel. They also disclose 2 channel power at 1kHz and full bandwidth with specified 8-ohm load impedance and distortion levels.  However, not too many years ago, they used to give you a summed power rating of all channels (i.e. 100 wpc x 7 = 700 watts), despite the fact that the receiver was incapable of delivering that power with all channels driven.  At least they've moved away from that rating style in their more recent product releases from what we've seen.

Yamaha RX-A3070

Yamaha Power Rating

Yamaha RX-A3070 Power Ratings various methods with 2CH ratings shown first

NAD T787 Receiver

MSRP: $2,500

NAD T787 Receiver Power

NAD T787 7CH Receiver is ONLY major brand rating ACD Power

Now in comparison, look how NAD rates their AV receivers.  Full disclosure of power per FTC for ALL channels driven.  They are stating rated power more honestly at 120 watts/ch x 7 then you're getting with the examples above with only 1 or 2 channels driven at 6 ohms, 1kHz and high distortion.  Sure, the number doesn't look as impressive, but it's real. Bravo!

The reality is the Denon receiver previously mentioned has a pretty beefy power supply (900 watts) spread across 13 channels, while the NAD has around a 1100-watt power supply spread across 7 channels. The latter clearly can hit its more honestly rated 120 wpc x 7 while the Denon cannot do 150 wpc x 13, let alone for 7 channels.  NAD rates this receiver as 200 wpc x 2 and de-rates for all channels driven.  Denon could have simply rated their AVR-X8500H 150 wpc x 2 and probably still achieve 115-120 wpc x 7 based on the size of the power supply and how their predecessor 7200WA performed on the bench.  This is an example where both products are very capable despite one manufacturer being more conservative in how they rate the power of their amplifiers. Manufacturers know this, but they're banking on the fact that you may not know as much, in order to make their product stand out among its competitors as being more "powerful."

Power Amplifiers

Loose power specifications aren't limited to just AV receivers. We are also seeing this trend with dedicated power amplifiers, most commonly with Class D topologies. The reason for this is most Class D amplifiers can easily deliver high power ratings at 1kHz, 8 ohms, but some have varying performance based on load impedance.  We've seen older ICE modules, for example, that did great at 1kHz at 8 ohms but couldn't deliver more than 1/3 rated power into 4 ohm loads above 3kHz. This is something often missed in most AV review magazines that only test at 1kHz and something that isn't usually disclosed in manufacturer specifications of these types of products. 

MSRP: $6,500


Lyngdorf TDAI-3400 Integrated Amplifier

Here is an example of a very expensive two-channel integrated amplifier from a company named Lyngdorf.  Their 2 x 400 watt (4 ohms) and 2 x 200 watt (8 ohms) power ratings look impressive upon first glance. But, when you look closer, they don't disclose bandwidth or distortion at full power but instead, only at 1 watt.  For a product of this caliber, that's simply unacceptable especially when many of their competitors still using Class AB amplifier topologies give full disclosure of power. It is possible that this product can deliver full rated power at full bandwidth with both channels driven. But, you'd never know it from their poor specsmanship.  

Wyred4Sound SX-1000R
MSRP: $1,799/ea

The next example can be seen from a company called Wyred4Sound. Their SX-1000R Monobloc retails for $1,799/ea and is rated for 625 watts into 8 ohms, and an impressive 1225 watts into 4 ohms.  Again, no specifications for distortion or bandwidth are given.

 Wyred4Sound SX-1000R

Wyred4Sound SX-1000R Monobloc Amplifier

These may be great products and I'm not debating their fidelity. However, the manufacturers should be embarrassed to offer so few objective performance metrics. As Dr. Floyd Toole says, "You usually get more useful information from the sidewall of a tire than you do from loudspeaker manufacturer specifications...."  I'm going to extend the usefulness of that phrase to how Class D amplifiers are being specified and sadly how the FTC is letting this go under the radar.

Monoprice Monolith-7

MSRP: $1,799

 Monoprice Monolith-7

Monolith Specs

Monoprice Monolith-7 Specifications

Yet when we look at relatively inexpensive amplifier from Monoprice ($1,799 for 200 wpc x 7), full disclosure of power is given for ALL channels driven per FTC testing protocol.  In fact, their website even shows full test data from the same Audio Precision audio analyzers we use for our product reviews! It makes you wonder just how many of these "high end" amplifier companies have access to this type of test gear or if they're just taking amplifier modules from chip vendors and just stuffing them into a box and hoping for the best.

Outlaw Audio Model 5000

MSRP: $599

 Outlaw Model 5000

Outlaw Model 5000 5CH Amplifier

If you take a look at every amplifier Outlaw Audio sells, they too give full disclosure of power.  In fact, we measured this very amplifier and it exceeded the 120 watts x 5 ACD.  How is it possible that a company can offer so much transparency on such an inexpensive product while another manufacturer of a product costing 10 times the amount cannot? Incidentally, both examples disclosing full power are classic AB linear amplifier designs.  Again, we typically see the lack of specifications on Class D power amplifiers and hope this article exposes that deficiency in order to nudge manufacturers to be more forthcoming with their power specifications. 


PutinSo, what have we learned from all of this?  Basically, the FTC has bigger fish to fry (like the Russians hacking our election) than worrying about amplifier power claims for consumer audio.  Since the work by the FTC to further study how to properly rate multi-channel power amplifier claims ceased over a decade ago, we don't expect much enforcement these days. Also, don't count on most manufacturers to do the right thing and offer full disclosure of power.  In fact, some receiver and most HTIB manufacturers are showcasing their bogus power claims via a sticker on the front panel or as the primary power rating in their online product page.  Sadly, consumers often have to be extra vigilant on seeking out the true 2CH, full bandwidth, 8 ohm power ratings to not be mislead by these inflated ratings.

Editorial Note about the FTC by Steve Feinstein

The FTC never evidenced any particular expertise for the finer points of audio amplifier design, and that lack of expertise was—and is—apparent in the many loopholes and inconsistencies in their power guidelines. The FTC should have hired experienced audio designers and industry professionals as consultants to implement their rulings, but to our knowledge, this was never done, or if it was, they never said so. Although the initial 1974 effort was well-intentioned, if a bit naïve (per the ridiculous and ignorant 1/3-power preconditioning requirement), their haphazard approach since 1974 makes it obvious that the FTC never really had the technical or organizational wherewithal that was required to do a truly credible, complete job.

At what point does full disclosure even make sense as we start seeing multi-channel amplifiers serving 10 or more channels from a single chassis?  The reality is, we don't listen to music or even watch movies with all channels driven.  However, that doesn't mean we should just accept inflated power ratings with little to no specifications of how they were derived does it? 

At Audioholics, we test 2-channels driven, full bandwidth for 8 and 4 ohm loads and ACD for up to 7 channels at 1 kHz for 8-ohm loads.  We also do CEA 2006 dynamic power testing as well to see how capable the amplifier is at delivering dynamic performance similar to how we listen to music.  This isn't a perfect test, but it will usually identify shortcomings in an amplifier’s ability to deliver stable power under heavy loading conditions.

For more information, see: Audioholics Amplifier Measurement Standard

As a consumer, it's of paramount importance to read the fine print in how manufacturers are specifying power, so you can make as close to an apples-to-apples comparison as possible.  If you see your favorite manufacturer fudging their power ratings like the examples shown herein, it wouldn't hurt to pop them an email asking them to do better.  Don't forget to tell them Audioholics told you so.  Be sure to vote in our online poll in the associated forum thread. Let your voices be heard!


FTC amendment for amplifier power 1998

FTC amendement at the register as of 2007


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Recent Forum Posts:

Johnny2Bad posts on August 01, 2018 20:38
The FTC Rule of the early 70's was developed at a time when the audio component marketplace was simpler than today and suffered from some abusive marketing. It's important to note that the FTC Rule never applied to a lot of products that are common in our market today, and the rules still apply to the same components they ever did. It has never applied to boom boxes, car audio, TVs, any device that is designed to operate as a complete system (such as a product comprising of an amp and speakers together),anything “portable” which means not connected to AC or one that contains a “handle” somewhere … the list goes on, actually.

It's also worth noting that the FTC Rule only applies to advertisements in print where certain power claims are made in the text. It does not prohibit other forms of power claim, only that they cannot be more prominent (text size, bolded, etc) than the FTC method figures. And to repeat, only to ads.

Not to webpages, not to downloadable brochures, not to owner's manuals, not to video, and not to non-advertising product literature of any kind. Since people no longer shop Bricks-And-Mortar stores they no longer encounter printed brochures. Back in the 70's and 80's a store would have hundreds of different take-home brochures on display.

And if you're not reading an ad in a printed magazine, or if that ad doesn't make certain power claims on certain component products, it doesn't apply either.

Most reputable manufacturers follow the FTC rule in composing their spec sheets.

The FTC attempted to expand the FTC rule to apply to multichannel components but yielded to industry pressure. The main argument against expansion was that buyers of multimedia gear would feel cheated when the new rules came into force and power claims fell at the same price point.

So it only applies to certain types of stereo and mono amplifiers, distributed from a US-based company, and only products sold by that company within the US, which doesn't come close to covering the entire market today.
PENG posts on August 01, 2018 16:48
T1m, post: 1261176, member: 86125
I bought my first stereo as a teenager in the early 1980s when everyone was posting the TRUTH, eg. 40 watts rms per channel, both channels driven into 8 ohms from 20hz to 20 kHz +/- .5 dB at no more than.05% thd.

It really isn't that bad. If you want manufacturers based their product's power ratings on 20-20000 Hz +/- 0.5 dB and 0.05% THD, you can simply look to current Denon models such as the AVR-X4400H, X6400H, X8500H, or Marantz models SR7012, SR8012. They all have THD rated 0.05%, 20-20 kHz, and in the past the 4000 series Denon and 7000 series Maratnz all measured well, with results better than their advertised specs. They do include some garbage specs such as the XXX watts, one channel diven at 1 kHz at 10 % THD, but as an informed consumer, you know full well to pay attention to the good stuff only.

Below is one example of the lab measurements I mentioned above.


"Denon rates the AVR-X5200W as follows:
  • 140 watts < 0.05% ; 20Hz to 20kHz 8 ohm load, unspecified channels driven
  • 160 watts (8 ohms, 2CH) and 250 watts (4 ohms, 2CH) dynamic power
Our test results validate Denon’s power specification at least for two channels driven. In fact we were even able to validate their 250 watt sticker slapped on the front panel, but only for one channel driven at 1kHz into 10% THD +N. They could really do away with that sticker but more POWAH sells, especially to less informed consumers, which is who they are targeting with this claim."
T1m posts on August 01, 2018 15:30
I just read the article and the posts. I am very disappointed with the manufacturers so called power ratings on their web sites! I had been thinking about purchasing a budget integrated amplifier or 2 channel stereo receiver and could not believe the garbage that most manufacturers had posted on their webpages and the almost complete lack of true power ratings. I bought my first stereo as a teenager in the early 1980s when everyone was posting the TRUTH, eg. 40 watts rms per channel, both channels driven into 8 ohms from 20hz to 20 kHz +/- .5 dB at no more than.05% thd.

I was fortunate enough to have subscribed to Canada’ Sound magazine in the early 1980’s and had the benefits of learning about speakers, amplifiers, and many related topics until it went out of print in about 1997 or 1998. Thanks to people like Len Feldman, Alan Lofft, Ian G. Masters, Peter Mitchell, Andrew Marshal, and especially Floyd E. Toole I was much more knowledgeable than the average person when I went shopping for audio and video equipment.

So when I started looking for the manufacturers specifications for their audio equipment I soon became frustrated and angry that they were posting such garbage for their “power ratings “. Almost completely useless!

Thank you so much for pointing out the lack of compliance to the FCA ratings. I wish that every magazine tested their products as thoroughly as Audioholics. I also would like to point out that it is not just the mid to high end products but also the budget equipment were the vast majority of people spend their hard earned money that should be concerned about too. If somebody is earning $20,000 a year has $500 or $1,000 that they have to purchase a piece of audio equipment they have the right to know what they are getting, just as much as someone who earns $100,000+ and has $5,000 to $10,000 to spend on some audio equipment.
gene posts on April 25, 2018 20:05
MrDIY, post: 1244892, member: 58198
Several thoughts:

The issue is esp acute in whole-house sound systems when all channels are driven by identical program material. This is not the case in home theater systems.

Yay for NAD for giving an IM distortion figure! IM seems to have been all but totally forgotten by the industry. I could say the same for tuner ratings in AV receivers: 30 & 50db quieting sensitivity in mono & stereo, adjacent channel rejection, distortion, capture ratio, selectivity, drift, etc. People who can afford a $3-10k piece of equipment are old enough to remember when such things were SOP for mfrs.
I've seen a few comments on this thread or perhaps others about IMD distortion testing.

The reality is, in most cases, THD+N is good enough info to have for today's wide bandwidth amplifiers. In fact, it's been my experience if you see good THD+N performance, than IMD will also be similarly good. IMD alone doesn't give you noise sprectra so I'd rather have full disclosure of power bandwidth with THD+N.

See: https://www.audioholics.com/audio-amplifier/the-most-memorable-audio-receivers-of-all-time/distortion2014sidebar
MrDIY posts on April 25, 2018 17:14
Several thoughts:

The issue is esp acute in whole-house sound systems when all channels are driven by identical program material. This is not the case in home theater systems.

Yay for NAD for giving an IM distortion figure! IM seems to have been all but totally forgotten by the industry. I could say the same for tuner ratings in AV receivers: 30 & 50db quieting sensitivity in mono & stereo, adjacent channel rejection, distortion, capture ratio, selectivity, drift, etc. People who can afford a $3-10k piece of equipment are old enough to remember when such things were SOP for mfrs.
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