Receiver Power Consumption vs Output Power

[gene]

Ever wonder how your favorite manufacturer rates power consumption on their AV receivers and how it relates to maximum available output power to your speakers? I can't tell you how many comments I've read on our forums or Youtube community alleging dishonest wattage claims based on the back panel power consumption of AV receivers. This article explores this topic to determine the truth. We give several product examples including power calculations which were vetted by the brands for accuracy.

If you think the back panel tells the whole story about the full capabilities of your AVR with respect to power, you need to read this article to see what's really up.

Read: Receiver Back Panel Power Consumption vs Max Output Power

The above example shows a 140wpc x 11 Pioneer receiver which is speced to output 880 watts max output power. So how can it only consume 340 watts? Did it break the laws of physics? Read the article.

 

[PENG]

Thank you Gene, this article is long over due!! I also loss count on how many times I had posted to caution posters who evidently were misguided by the power consumption figure on the back panel as well as the "power consumption" and "maximum power consumption" specifications found in owner's manual. Note: Yamaha does provide both "consumption" and "max consumption" though not on all models and not always.

Next time such posts based on misconception/misunderstanding of specs come up, we could respond by simply posting a link to this article.

 

[lovinthehd]

Definitely can think of many times I would have pointed someone to this article and now can! Thanks!

 

[Speedskater]

Yet all these rating are based on continuous sine wave power tests. Music and even train wreck movie sound tracks place very different demands on an amplifier.

 

[highfigh]

Let's all go to Beast Buy and ask their sales people how the AVRs on their shelves can output 950W when they only use 600. They really need to stop showing power for all channels added together on the price cards.

 

[gene]

 

[VMPS-TIII]

The Monolith 7X power amp shows 1800 watts on the back panel with a 15 amp circuit breaker. 1800/7 = 257W per channel. When I use a Kill-a-Watt meter to measure energy use with all 7 channels driven at a volume of 65 on the Denon 4700 with Auro-3D mode it displays 200 watts.

When the volume is 35 the Kill-a-watt reads 158 watts. The amp seems to require approx. 150 watts to turn on and only rises by about 50 watts when you get to 65 on the volume. It's hard to imagine energy use rising 7x. Is it possible the 1800 watts is simply reflecting 15 amps?

Is there a class D amp that offers the same amplification and quality as the Monolith 7X at a similar price point?

 

[gene]

The Monolith 7X power amp shows 1800 watts on the back panel with a 15 amp circuit breaker. 1800/7 = 257W per channel. When I use a Kill-a-Watt meter to measure energy use with all 7 channels driven at a volume of 65 on the Denon 4700 with Auro-3D mode it displays 200 watts.

When the volume is 35 the Kill-a-watt reads 158 watts. The amp seems to require approx. 150 watts to turn on and only rises by about 50 watts when you get to 65 on the volume. It's hard to imagine energy use rising 7x. Is it possible the 1800 watts is simply reflecting 15 amps?

Is there a class D amp that offers the same amplification and quality as the Monolith 7X at a similar price point?

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The Monolith is an ATI amp and they are honest about power ratings. The 1800 watts is likely close to a max rating so if you factor 70% max efficiency, that's about 1250 watts available to the speakers / 7 = 180 watts/ch.

 

[PENG]

The problem with trying to use the back panel consumption number remains the same, manufacturers don't tell you how they derived that number. D+M did not do it either, until now, obviously only thanks to Gene, who somehow got the information from them. If you look at Yamaha's consumption specs from their owner's manuals, it is very obvious they are not using the same standards that D+M are using. ATI, Monolith is also different as per Gene's response in post#8.

So the bottom line, is, while the back panel numbers are useful, you can use them to project/estimate real world power output. In relative sense though, it is reasonable to say if the back panel number for say, the Denon AVR-X4700H and Marantz SR7015 are the same (and they are), then the power output of the two will most likely be the same, just don't compare it to a Yamaha AVR based on the same principles.

 

[VMPS-TIII]

So the bottom line, is, while the back panel numbers are useful, you can use them to project/estimate real world power output. In relative sense though, it is reasonable to say if the back panel number for say, the Denon AVR-X4700H and Marantz SR7015 are the same (and they are), then the power output of the two will most likely be the same, just don't compare it to a Yamaha AVR based on the same principles.

The Denon AVR-X4700H uses 46 watts of energy when amp assign is set to "pre-amp" mode and eternal amps power all speakers. The surround mode and the volume setting do not alter the energy use in my test. The normal energy fluctuation you would expect from different volume settings moves to the external amp(s) selected.

The new Denon pre-amp mode effectively turns the AVR into a preamp. I am a little surprised that the Denon will still get warm to the touch even in this mode without top mounted fans.

 

[highfigh]

The Denon AVR-X4700H uses 46 watts of energy when amp assign is set to "pre-amp" mode and eternal amps power all speakers. The surround mode and the volume setting do not alter the energy use in my test. The normal energy fluctuation you would expect from different volume settings moves to the external amp(s) selected.

The new Denon pre-amp mode effectively turns the AVR into a preamp. I am a little surprised that the Denon will still get warm to the touch even in this mode without top mounted fans.

It still has resistors & other components and the energy wasted by them is transformed to heat.

 

[Trebdp83]

It was a very informative video and it contained what is now, sorry Psycho, my favorite shower scene.

 

[jeffca]

Honestly, I'd never consider an AVR. Not that they sound terrible, but I'm not a fan of receivers because of the cost, lack of modularity and inability to easily upgrade. Also, my next system will be a DIY, fully active system so a receiver isn't an option.

 

[Trebdp83]

Honestly, I'd never consider an AVR. Not that they sound terrible, but I'm not a fan of receivers because of the cost, lack of modularity and inability to easily upgrade. Also, my next system will be a DIY, fully active system so a receiver isn't an option.

Make two and send me one.

 

[CajunLB]

Honestly, I'd never consider an AVR. Not that they sound terrible, but I'm not a fan of receivers because of the cost, lack of modularity and inability to easily upgrade. Also, my next system will be a DIY, fully active system so a receiver isn't an option.

I’m confused? Your going to diy your own processor and amplification? If so that’s impressive.

 

[Dan Maldonado]

Ok. So my Onkyo 805 is rated at 9.5 amps which is used for LCR and processing going to SVS ultra towers, and doing processing for surrounds (4 channels) to an Onkyo HTR 940, with a 5.9 amp rating. I would say that they’re adequately powered. But someone help me with the math on this please!

 

[VMPS-TIII]

Onkyo 805 offers 130 watts per channel x 70% efficiency = 91 watts per channel. Onkyo HTR 940 is the same. You should have plenty of power provided your speakers are relatively efficient.

 

[Dan Maldonado]

Onkyo 805 offers 130 watts per channel x 70% efficiency = 91 watts per channel. Onkyo HTR 940 is the same. You should have plenty of power provided your speakers are relatively efficient.

SVS Ultra speakers are not super efficient and Onkyo totally underrated the power output for the 805. They’re also four ohm speakers, not really 8. https://www.soundandvision.com/content/test-report-svs-ultra-tower-surround-speaker-system-page-3 Its more like 180 plus into 8 ohms and over 300 into four ohms for the 805.

805 bench test:

B&W 600 Series Speaker System and Onkyo TX-SR805 A/V Receiver HT Labs Measures: Onkyo TX-SR805 A/V Receiver

HT Labs Measures: Onkyo TX-SR805 A/V Receiver Five channels driven continuously into 8-ohm loads: 0.1 percent distortion at 162.0 watts 1 percent distortion at 184.5 watts All channels driven continuously into 8-ohm loads: 0.1 percent distortion at 120.4 watts 1 percent distortion at 151.7 watts...

www.soundandvision.com

940 bench test:

Onkyo HT-S990THX Integrated Home Theater System HT Labs Measures

HT Labs Measures: Onkyo HT-S990THX Integrated Home Theater System Two channels driven continuously into 8-ohm loads: 0.2% distortion at 162.6 watts; 1% distortion at 189.4 watts Two channels driven into 4-ohm loads: 0.2% distortion at 213.6 watts; 1% distortion at 263.1 watts All channels driven...

www.soundandvision.com

Are these really that powerful?!? I am not sure if it’s necessary for me to go separates to get adequate power to these speakers. Just toying with the idea of going separates (amp and pre/pro).

 

[ryanosaur]

SVS Ultra speakers are not super efficient

Ar 88dB sensitivity they are considered reasonably efficient and 64w should yield ~106dB @1meter. To milk anything more out of your speakers, you would need to double the power to 128w for a +3dB increase, and double again to 256w for another +3dB.
According to Sound &Vision, it looks like the 3 ohm minima has a pretty benign phase angle which means it may be challenging to drive at sustained high SPL but shouldn't be an amp buster... as long as the amp stage is stable for 4 ohm loads.

 

[Dan Maldonado]

Ar 88dB sensitivity they are considered reasonably efficient and 64w should yield ~106dB @1meter. To milk anything more out of your speakers, you would need to double the power to 128w for a +3dB increase, and double again to 256w for another +3dB.
According to Sound &Vision, it looks like the 3 ohm minima has a pretty benign phase angle which means it may be challenging to drive at sustained high SPL but shouldn't be an amp buster... as long as the amp stage is stable for 4 ohm loads.

Yeah these are stable at 4 Ohms. I guess my final question is it worth even getting an amp since they’re pretty good amps on their own even though they’re AVR’s?