Can Sound United Bring Honest Power Ratings to AV Receivers?

Last year I wrote about  how the Federal Trade Commission (FTC) has failed consumer audio in its Amplifier Rule to combat the unrealistic power claims made by many hi-fi amplifier manufacturers established back in 1974. I discussed how we've noticed a trend of grossly inflated power ratings lately with many Atmos AV receivers that is now also bleeding over to multi-channel power amplifiers too. It seems the FTC has become too complacent with validating and enforcing amplifier power claims since their efforts to rule on multi-channel power amplifiers ceased over a decade ago and manufacturers are taking advantage of it. This is especially true since, other than Audioholics, there are NO major AV publications or 3^rd-party advocacy groups in the USA measuring AV receiver amplifier power claims. Sadly, Sound & Vision magazine has recently abandoned measurements in their product reviews.

In this editorial, we make a call to action to both manufacturers and consumers to specify amplifier power more honestly, and to demand it from their favorite receiver and/or amplifier companies.

Join our Movement by signing our TiP (Truth in Power) Petition NOW!  (please don't donate $$$, just signing is good enough)

Editorial Note about the FTC and Power Ratings by Steve Feinstein:

Back in the ’60s and early ’70s, stereo manufacturers would use all kinds of deceptive wattage ratings. There was Continuous or RMS, but since this was the smallest, least-impressive number, it was always listed last, in small print, if listed at all. Double the RMS was “Dynamic” or “Peak” or “Music” power—the rationale being that an amplifier could likely deliver about double its continuous rating on a temporary peak in the music. Double that was a really bogus number called “IPP” or Instantaneous Peak Power. The flimsy rationale was that an amplifier—if it had enough of a power supply—could probably muster about double its Peak power for the briefest of instants, if it had the wind at its back and you completely disregarded the distortion.

So a 30-watt/channel RMS stereo amplifier became a 60-watt/ch peak amp, which became a 120-watt IPP amp. Adding together the two channels, manufacturers would advertise, “240-watt Amplifier!” for a 30-per-side unit.

Therefore, in 1974, the FTC came in and mandated that audio amplifier power specifications had to state RMS/continuous power first, in the largest type, and that it had to be specified over what frequency bandwidth, at what THD distortion level, and both channels had to be driven simultaneously. Furthermore, the FTC mandated a warm-up or “preconditioning” period of an hour at 33% of rated power at 1kHz before measurements were taken.

The manufacturers hated this one, because 33% power is right in the heart of the least efficient operating range for typical Class AB amplifiers (which all of these were), and so the amps would run very hot during the preconditioning period. That necessitated large, heavy heat sinks for new designs, or sometimes a downgrade in power ratings for existing designs in order to meet the new requirements. For example, Dynaco—a well-regarded manufacturer of better-than-midgrade electronics—had to de-rate their popular SCA-80 integrated amplifier from 40 watts RMS per channel to 30 watts RMS per channel, because the unit ran too hot during the new FTC-mandated preconditioning period.

But the FTC mandate applied to 2-channel stereo equipment, so when multi-channel home theater receivers, self-contained powered subwoofers and computer speaker systems came on the scene about 20-25 years ago, the original 1974 FTC mandate didn’t apply to them. Manufacturers saw this loophole and took big advantage, hence 7-channel receivers with bogus ratings of “150 watts x 7,” subwoofers that say they have “2000 watt” amps and $150 3-piece computer speakers that claim to have “300 watts.”

With Sound United's recent offer to acquire of Pioneer and Onkyo/Integra, it got me thinking. This Sound United entity can be a force of goodwill if it so chooses, since it will eventually hold a major stake in the AV receiver marketplace (assuming Pioneer Onkyo/Integra sale finalizes) and thus they can lead by example to get the other brands to fall in line and rate amplifier power honestly and consistently.

Sound United wields great marketing power and influence with their collection of audio brands. This is their opportune time to step up and lead the industry!

What Do We Mean by Honest Power Ratings?

Honest power ratings should be rated at unclipped (aka. undistorted), continuous power levels and should start with the following for stereo and multi-channel AV products:

• 2CH Driven, Full bandwidth 20Hz to 20kHz @ 8-ohms over a specified distortion rating as % THD+N (preferably under 0.1% THD +N)

Yamaha RX-V659 Full Power Bandwidth Test (2CH Driven, 8 ohms < 0.1% THD+N)

At full continuous unclipped power (132wpc x 1; 8 ohms, 120wpc x 2; 8 ohms; full bandwidth with less than 0.1% THD+N), the RX-V659 still maintained excellent bandwidth linearity with a -3dB point of 65kHz despite the fact that we were driving the receiver way beyond its rated 100wpc power specification. This was the type of performance we got from a $400 AV receiver only 13 years ago. You don't get an amp section this good in most AV receivers costing twice as much these days. Yamaha conservatively rated this receiver to be 100wpc and it over delivered. Bravo!

2CH driven full bandwidth continuous power should be the FIRST power rating a consumer sees both in product literature and store displays. Peak or MAX power figures should NEVER be listed as the first power spec consumers see.This is per mandate of the FTC Rule, which over the years hasn't been rigidly enforced.  Otherwise, the reason for this article and call to action wouldn't be needed.

While most AV receiver manufacturers still rate power of their products 2CH driven FTC method, it's often buried in the user manual or shown below a much less conservative rating method as follows:

• 1CH Driven, 1kHz @ 6 ohms < 10% THD + N

Note: 10% distortion represents hard clipping on an oscilloscope and is only -20dB below the fundamental. This is very audible and should NOT be considered to be a usable long term power rating.

Top Image: Pioneer VSX-834 ; Bottom Image: Yamaha RX-A3070

Last time we wrote about this topic (Pioneer Inflating Power Ratings), many manufacturers were spec'ing 1CH driven power or high distortion power first as you can see in the Pioneer and Yamaha examples above. The Pioneer example is just utterly ridiculous. It has inexperienced consumers believing they are getting a 165wpc AV receiver for under $400 when in fact they are actually only getting 80wpc, properly rated.

Alas, if you complain enough, changes happen!

Sound United Receiver Power Ratings

Notice how each of the brands NOW show 2CH, full bandwidth 8 ohm power ratings FIRST in the specs on their website, followed by the 1CH driven, 6 ohm, 1kHz rating at 10%. I'm happy to see this progression since we've been talking about this. But, I'd ultimately like to see the 1CH 10% power spec dropped completely off product literature for amplifiers and AV receivers.

The Dreaded AVR Power Sticker

Dreaded 1CH Driven, 6-ohm, 10% Power Sticker on Newer Denon AV Receivers

This is really a 150 wpc receiver inflated to 260 watts.

Despite 2CH power specs are on most manufacturer websites, they still often stamp a 1CH driven, 6-ohm, 10% power sticker on the front of their AV receivers which is what the consumer sees first. BIGGER numbers sell to the uninitiated.

Sticker on Front Panel of an Onkyo Receiver Displayed at Best Buy

Notice how the inflated 155wpc power is the primary selling point of this product with very small fine print below disclosing the actual power is almost half that rating at 80wpc per FTC.

In our opinion, the 10%, 1CH driven power spec is a nonsense way of rating a multi-channel product and is only done so to inflate power ratings. A 150wpc receiver normally rated with 2CH driven can now be rated as 260wpc with this 1CH inflated power rating method. This gives the illusion that their AV receiver is much more powerful than it really is. It doesn't even account for the fact that said product couldn't deliver anywhere near this 260 watt power figure with multiple channels driven simultaneously.

A Silver Lining in How Marantz Rates Power?

Marantz 70% Power Guarantee on AV Receivers (5CH driven)

If you carefully look at the way Marantz specs most of their AV receivers on their website, they have an additional power spec - the "70% rule" which mandates that their products will deliver 70% of rated 2CH power with up to 5 channels driven simultaneously. That's a great spec and we hope Sound United makes a BIGGER deal of this rating in future products and marketing literature. It's a true silver lining in how they rate power in AV receivers especially while most of the industry has moved to the dreaded 1CH driven spec. Marantz still specs the 1CH driven, 10% power as well, but we really hope that becomes a relic of the past as it's just noise, or in this case, distortion.

Understanding the Power vs Distortion Curve

Rating at least 2CH driven, full bandwidth, ensures the end user gets a product that can deliver real rated power for stereo music operation. It allows them to plan accordingly when matching speaker sensitivity and room output requirements to how much power they may need.

Denon AVR-X3300W Power vs Distortion (2CH Driven)

The horizontal line represents the linear operating region of the amplifier (where the noise floor dominates) while the vertical curve upward past the knee represents the distortion dominant region. Amplifier power should be rated to the left of the knee, NOT at the distortion dominant vertical region.

For more information on this topic, read: Receiver Power Ratings Game

Understanding Power Ratings in AV Receivers

More honest ratings also ensures that the manufacturer rates power at the horizontal portion of the power vs. distortion curve where the amplifier behaves linearly instead of the vertical line where distortion starts to dominate. This is why I believe power ratings should be specified at or below 0.1% THD + N and like to refer to this as the "fidelity firewall" when it comes to rating electronics.

It doesn't take the detective work of Sherlock Homes to realize multi-ch AV receivers from 20 years ago not only had less channels of internal amplification and were rated at less output power, but also had larger power supplies and weighed more. Technology advances do NOT account for this discrepancy, even factoring in the more efficient Class D amplification found on some models.  Less transparency in power ratings does.

Let’s give a simple example: A Denon AVR-3600 5CH receiver from the late 90s had an 8amp fuse, weighed 48lbs and was "only" rated at 110wpc x2CH driven and 90wpc all channels driven (ACD). Yes, they actually gave an ACD rating while also conservatively rating full power bandwidth compared to a similarly-priced product from the same brand today that boasts 250wpc 1CH driven, packing in 11 amplifiers and weighing a good 18lbs less. The older Denon power ratings were measured on the linear portion of the Power vs. Distortion curve and they built in a beefy enough power supply to deliver near the same power with ACD as their 2CH power rating.  Those were the “good ole days” of only 5 or 7 built in amplified channels. Today those same sized chassis have to carry 9, 11 or 13 amplified channels using the same or smaller-sized power supplies.

It’s important to emphasize unequivocally that we aren’t picking on Denon. We’ve given many of Denon’s products stellar reviews and you’ll find Denon gear in some of our reviewer’s setups (including yours truly) over the years. To Denon's defense, this is common with all of the AVR brands today since their products do so much more in terms of HD audio and video decoding and switching, streaming, room correction, and licensing of technologies to make this all happen. Furthermore, some other brands are fudging and inflating their numbers in grossly more suspect ways, especially in HTIB products. This further strengthens the case for more oversight needed.

How We Suggest Power Be Measured on AV Receivers

While some enthusiasts may rightly want All Channels Driven (ACD) tests all the time, it’s often impractical and not a real world test condition since there is never any time when real program material will require full-bandwidth power from ACD simultaneously. It's particularly impractical to rate ACD, especially in products with more than 7 channels of internal amplification because they will often exceed the available power from your wall outlet even if they were capable of delivering it.

Marantz SR8012 ACD Power Test

We currently do test ACD for receivers with up to 7CH driven in most of our reviews as you can see in the Marantz SR8012 power vs distortion graph above.

There comes a point where even if you build an amplifier with an infinitely large power supply, you're testing the limits of the wall outlet under such testing conditions (i.e. 15A, 120V = 1800 watts). Factor in 70% efficiency for Class AB amplification, that leaves you with a best case scenario of 180wpc x 7 or 140wpc x 9, 115wpcx11, and 97wpc x 13 ACD. In a dedicated amplifier, it's possible to have a power supply big enough to hit these power figures but most AV receivers simply don't.

Thus in addition to a 2CH driven, full bandwidth rating, we'd like to take the power spec one step further by proposing an additional power rating as follows for AV receivers:

3CH driven, full power bandwidth, 8 ohms, at specified % THD+N (max 0.1% THD+N) with remaining channels driven at 1/8th power.

Having this data will prove that the AVR has enough juice in its internal power supply to handle a real load condition while maintaining at least 70% power rating across the 3 front LCR channels.

How About Specing Maximum Power Consumption?

If receiver companies would go back to specing maximum power consumption on the backpanel of their AVR's, that would also give consumers useful information in trying to guesstimate available power with multiple channels driven. For example, if the back of a 9CH AV receiver says "max power consumption: 1100 watts", then the end user can be confident that the power supply is probably large enough to deliver 90-100 watts/ch ACD (factoring in inefficiencies). Another example would be like how Denon spec'd their venerable AVR-5803 with a 12A max power consumption on the back panel. 12A at 120V is 1440 watts usable for 7 internal amplifiers. Now that's a receiver that came damn close to delivering rated 170wpc x 7 ACD. What a beast! Sound United please bring back the super receivers!

Note: Unless the power consumption on the backpanel of an AV receiver says "max power consumption", don't assume that is the actual maximum power the unit can draw. In many cases, we've found the power consumption #s to be rated with only 2CH driven or with remaining channels driven at 1/8th power.

Sony STRDN1080 7.2CH AV Receiver Product Sticker @ Local Best Buy

1155 watts is NOT Max Power Consumption or Power Delivery. It's BOGUS!

Beware of the LARGE Fictional Total Power Specification

Sadly, we noticed a disturbing trend with many lower cost products on the display floor at the local Best Buy. Some manufacturers are specifying total power by taking the max 1CH power rating and multiplying it by the number of channels to advertise the product can produce that much power! This is obviously NOT a maximum power consumption rating as we suggested before but instead power manipulation being pawned off as bad science fiction. A quick glance at Sony's website reveals they don't even specify amplifier power 2CH driven per FTC. Instead, they listed this particular model as "165 W (6 ohms, 1 kHz, 1ch driven THD 0.9%)" and thus multiplied by the # of channels (7) to come up with their fictional 1155 watts figure. This 20lbs budget receiver would be lucky to produce 100wpc with 2CH driven unclipped into 8 ohms and certainly much less once multiple channels are driven simultaneously.

Yamaha YHT-4930UBL 5.1CH HTiB

Just look at this example of a Yamaha HTiB system that actually gives a total power output by summing the maxed clipped 10%, 6 ohm power with 1CH driven with the # of channels (5) for a whopping 725 watts despite the receiver of the system is only rated at 70wpc with 2CH driven per FTC method. I'm actually surprised Yamaha spec this system as 825 watts since it also comes with a 100watt powered subwoofer. Sadly, this is a very popular and highly rated system by consumers. It wouldn't even be in this article had Yamaha just spec'ed it more conservatively.

In our observations, it appears as though marketing pressure may be a factor for premium brands eaggerating their power specifications to compete with these inflated summed power numbers of lower tier products. High quality brands (let’s use Denon again as an example) have to compete against inferior quality products that slap “1200 watts of power!” stickers on their products. To the uninformed consumer, which would you choose? The "1200 watt" AVR that comes with FREE speakers or the properly spec’d Denon at 90wpc?

What About 4-Ohm Power?

I do think it's important to check power into 4-ohm loads for at least 2CH driven, but in order for most AV receivers to get the UL certification to be 4-ohm safe, they put in an impedance switch and test at the low setting to let the amplifiers clip at a lower power level, and thus dissipate less heat. Using the low setting (if an AVR has it) does NOT allow the receiver to drive the low impedance better. In fact, it starves your speakers of power when you flip to the low setting which is something we usually recommend against. I am not really urging AV receiver companies to spec power into 4 ohm loads since I realize it's unrealistic for most products to be expected to do so without current limiting. However, it would be great to differentiate flagship products IF manufacturers provided a 2CH driven full power bandwidth rating into 4 ohm loads which will again help consumers make more informed purchasing decisions to determine whether or not they need to boost amplification of their system based on having difficult speaker loads.

For more information, see: Setting the AV Receiver Impedance Switch

Emotiva XPA-9 Gen3 9CH Amplifier rated with only 1CH Driven, Full Bandwidth!

What about ACD Power Ratings?

Dedicated amplifiers and very high caliber AV receivers can still be measured ACD (8 ohms) if the manufacturer chooses to do so within the limits of the available wall power. In fact, we commend brands like NAD and Arcam for providing both 2CH full power bandwidth and ACD power ratings. We also commend brands like Parasound, Monoprice, ATI, and Outlaw Audio for also giving full disclosure of power with 2CH and ACD driven. In our opinion, Emotiva has been a little less transparent with their power ratings of some of their Gen3 multi-ch amplifiers (ie. XPA-9 and XPA-11) which employ SMPS power supplies unlike their older generation XPA series that ulitized linear supplies. It's sad to see many of their recent Gen3 products rated with just 1CH or 2CH driven and we hope this editorial is a call to action on their part to provide ACD power for their products like many of their competitors do (ie. ATI, Monoprice, Outlaw, etc).

See our article: ACD Power Amplifier Test for more information on this topic including the limitations and practicality of this type of testing.

Can Sound United Lead the Way?

Sound United has recently captured MOST of the AV receiver market with the following brands:

• Denon, Marantz, Onkyo, Integra, and Pioneer (the latter three aren’t yet a done deal, pending shareholder vote).

The only major players remaining in the AV receiver marketplace now are Yamaha and to a lesser extent, Sony and premium brands like Anthem, NAD and Arcam.  NAD and Arcam already disclose power honestly so we exclude them in this comparison. Good job! Anthem rates power in their receivers with 2CH driven at a time and so far hasn't published the 1CH driven, 10% power spec to our knowledge.

We think there’s a unique opportunity for Sound United to make a mark in the industry. Imagine now if Sound United brands dropped their 1CH driven power ratings and instead switched back to 2CH as default with an abbreviated mult-ch power rating as we suggested above? Yamaha and Sony would have no choice but to follow their lead. Receivers will finally be rated at realistic power levels giving consumers realistic expectations of performance to make better educated decisions on whether or not they need to add additional amplification to their systems to achieve higher output levels, especially on difficult to drive speaker loads.

Inflated power ratings are a pet peeve of mine since I feel the industry has just taken it too far with recent AV receivers and HTiB products. Let's stop deluding ourselves into thinking a $1k 9CH receiver is really delivering 150wpc  x 9 for a total of 1,350 watts and instead put forth realistic claims about these modern marvels that decode, switch and stream everything to our hearts’ content. They are, however, NOT powerhouses in terms of driving speaker systems and that should be kept in mind. I personally think ALL AV receivers starting at $1k should come standard with preamp outputs capable of outputting a clean 2Vrms signal for those wanting to add external amplification to take the performance of their systems up a notch. Good amplification is cheap these days, so instead of starving consumers with a promise of inflated power, we should be guiding them to an upgrade path to more power when it's needed through external amplification.

Take our Amplifier Power Quiz to see when it's time for you to upgrade the power of your AV receiver.

> Join our TiP Movement - Demand Honest Power Ratings in AV Receivers! <
(please don't donate $$$, just signing is good enough)

The Audioholics Proposed Solution

In our opinion, ALL manufacturers should rate their AVRs as follows:

1.  2CH Driven, Full Bandwidth continuous power, 8 ohms @ a specified % THD+N (recommended < 0.1%).
2.  3CH Driven @ Full Bandwidth continuous power, 8 ohms @ a specified % THD+N with remaining channels driven at 1/8th power rating.
   (3CH driven should be > 70% 2CH driven power rating.)
3. Specify maximum power consumption either in amps (ie. 10A) or actual power (ie. 1,200 watts).
   

*Note:  Additional power ratings can be given as the manufacturer sees fit, but these first two primary power specifications should be listed first in all product literature and store displays.

Additionally, all sales based websites (Amazon we’re talking to you) and big box stores (Best Buy we’re talking to you) should commit to asking manufacturers to adhere to these minimal standards.

I think many (if not all) enthusiasts will agree that we have an underlying problem here that needs industry leadership. That leadership needs to come first and foremost from a company that has the respect of the audio and home theater community; the company portfolio and market share to move the needle; and the sheer will to do the right thing for the consumer and the hobby we all care passionately about.

I formerly ask Sound United to consider my proposal for honest claims in receiver amplifier power ratings as a service to the industry and their large consumer base most of whom are receptive to buying higher caliber, more powerful products IF they can actually be differentiated more transparently. I also ask that Yamaha, Sony, Emotiva, and all AVR brands take the lead in adopting this honest ratings opportunity. We ask that the 1CH driven, 10%, 6-ohm power figures be terminated from ALL products. Let's strive for more realistic power specifications at or below the "fidelity firewall."

Truth has become a marketable commodity in an era of fake news. Let the truth set you free!

We’re calling this the Truth in Power (TiP) Movement. And that challenge is going to need our readers’ voices too. Tell us what you think and please sign our petition! Let's MAGA - Make Audio Great Again!