Wattage of AV receivers

[Hm5540]

Hi, I was going through the specs of many AV receivers and all of them show 100 or 130 watt per channel 1 channel driven. Does it means that when we are running just 1 channel among 5 or 7 channels, only then iy provides 130watts however when all channels are working playing a movie, will the power be reduced. And 130 watt will be divided among 5 or 7 channels

 

[lovinthehd]

Pretty much. But does indicate what one channel is capable of at a given time. The typical ACD (all channels driven) rating will be less unless they are deliberately marketing for say a lower wattage spec that can be obtained with all channels driven (but marketing being what it is and people's love for larger numbers of "watts"....). ACD ratings really aren't reflecting real life use either (i.e. needing full power simultaneously), but if you want to see what they are, try and find a bench test where they're providing such like this for example, for one of my avrs https://www.soundandvision.com/content/denon-avr-4520ci-av-receiver-test-bench

Keep in mind a doubling of power would represent a difference of 3dB spl. Difference between 100 and 130 watts represents all of 1.1dB difference in spl so typically the power among avrs is fairly close in that sense, too.

 

[Swerd]

If you want to compare the power ratings of different AVRs, pay attention to only one type of rating. That is the power available when 2 channels are driven, when measured as continuous power stated in watts, while driving an 8 ohm load, over the full audio frequency range of 20 to 20,000 Hz, with a defined level of total harmonic distortion (THD) such as 0.1% THD.

Sometimes you'll see the initials RMS or FTC (Federal Trade Commission) associated with these ratings. The FTC requires that all amps and receivers sold in the US have these power ratings. This allows you to easily compare the power available in different receivers.

Ignore the other types of power ratings. Using them is like comparing apples and oranges.

 

[Keith1964]

What i found funny is, i just bough a new in box Sony STR-DA5400ES AV receiver that retailed new for $2000, it gets great reviews but, i was on Sound and Vision's website, and they do bench tests on AV receivers. The STR-DA5400ES is rated at 120 watts 2 channels driven, but it bench tested at only 39 watts per channel with 5 channels driven at once. I then for comparison only, i looked at a cheaper $600 Sony STR-DN1060 AV receiver, the $600 Sony bench tested at 79 watts per channel with 5 channels at once. How can a $600 Sony bench test higher with 5 channels driven than a $2000 Sony ES AV receiver?

 

[ellisr63]

If you want to compare the power ratings of different AVRs, pay attention to only one type of rating. That is the power available when 2 channels are driven, when measured as continuous power stated in watts, while driving an 8 ohm load, over the full audio frequency range of 20 to 20,000 Hz, with a defined level of total harmonic distortion (THD) such as 0.1% THD.

Sometimes you'll see the initials RMS or FTC (Federal Trade Commission) associated with these ratings. The FTC requires that all amps and receivers sold in the US have these power ratings. This allows you to easily compare the power available in different receivers.

Ignore the other types of power ratings. Using them is like comparing apples and oranges.

Interesting that this is the way it used to be...when did it change to the way it was prior to the 1980s again?

Sent from my SM-T830 using Tapatalk

 

[Keith1964]

Interesting that this is the way it used to be...when did it change to the way it was prior to the 1980s again?

Sent from my SM-T830 using Tapatalk

What about all channel driven power? Especially for home theater surround sound. I still don't understand how Sound and Vision bench tested the $600 Sony STR-DN1060 could measure higher in 5 channel driven at once power 79 watts, to the 39 watts 5 channel drive at once for the $2000 STR-DA5400ES? In 2 channel the $2000 5400ES is rated at 120, and the $600 DN1060 is rated at 100. So according to Sound and visions bench test's, the DA5400ES rates higher in 2 channel, and the cheaper DN1060 bench tested better in all channel driven power. You would think the heavier 40 pounds, more expensive ES model would bench test better in all areas, than a cheaper 20 pound model.

 

[ellisr63]

What about all channel driven power? Especially for home theater surround sound. I still don't understand how Sound and Vision bench tested the $600 Sony STR-DN1060 could measure higher in 5 channel driven at once power 79 watts, to the 39 watts 5 channel drive at once for the $2000 STR-DA5400ES? In 2 channel the $2000 5400ES is rated at 120, and the $600 DN1060 is rated at 100. So according to Sound and visions bench test's, the DA5400ES rates higher in 2 channel, and the cheaper DN1060 bench tested better in all channel driven power. You would think the heavier 40 pounds, more expensive ES model would bench test better in all areas, than a cheaper 20 pound model.

It was required to do testing for 20hz-20k at 8ohms for rated power with all channels around the 80s. Prior to that it was at a single frequency, something like 1k for rated power..which meant about the same as the ratings we get now.

Sent from my SM-T830 using Tapatalk

 

[lovinthehd]

What i found funny is, i just bough a new in box Sony STR-DA5400ES AV receiver that retailed new for $2000, it gets great reviews but, i was on Sound and Vision's website, and they do bench tests on AV receivers. The STR-DA5400ES is rated at 120 watts 2 channels driven, but it bench tested at only 39 watts per channel with 5 channels driven at once. I then for comparison only, i looked at a cheaper $600 Sony STR-DN1060 AV receiver, the $600 Sony bench tested at 79 watts per channel with 5 channels at once. How can a $600 Sony bench test higher with 5 channels driven than a $2000 Sony ES AV receiver?

Link up both so we can see the details?

 

[Keith1964]

Link up both so we can see the details?

I don't know how to do that, just go to SoundandVision.com and type in STR-DA5400ES and STR-DN1060 under reviews.

 

[lovinthehd]

I don't know how to do that, just go to SoundandVision.com and type in STR-DA5400ES and STR-DN1060 under reviews.

Just copy the url and paste it here, usually it's faster to just use a search engine with a search like "Sony STR-DA5400ES bench test"

Sony STR-DA5400ES A/V Receiver HT Labs Measures

HT Labs Measures Five channels driven continuously into 8-ohm loads: 0.1% distortion at 39.4 watts 1% distortion at 45.0 watts Seven channels driven continuously into 8-ohm loads: 0.1% distortion at 37.3 watts 1% distortion at 41.9 watts Analog frequency response in Analog Direct mode: –0.04 dB...

www.soundandvision.com

Sony STR-DN1060 A/V Receiver Review Test Bench

Test Bench Two channels driven continuously into 8-ohm loads: 0.1% distortion at 101.6 watts 1% distortion at 132.9 watts Five channels driven continuously into 8-ohm loads: 0.1% distortion at 78.1 watts 1% distortion at 97.1 watts Seven channels driven continuously into 8-ohm loads: 0.1%...

www.soundandvision.com

I'd guess that the DA5400ES has a more aggressive protection design like some Yamahas seem to employ. Clearly the 5400 has more power per channel, just not ACD/simultaneously which isn't likely going to be a problem in real use.

 

[Swerd]

Interesting that this is the way it used to be...when did it change to the way it was prior to the 1980s again?

As far as I know, the FTC regulations, once they were established in 1974, were always the same. In 2007 changes to these regulations were proposed to reflect multichannel AVRs. The FTC ruled in early 2008 to keep the 2-channel requirement as it always was. It would have made more sense to rate all channels driven instead of only 2 channels, but the FTC apparantly decided it had greater problems than audio amplifiers to worry about.

https://www.ftc.gov/sites/default/files/documents/federal_register_notices/trade-regulation-rule-relating-power-output-claims-amplifiers-utilized-home-entertainment-products/080227trade.pdf

It was required to do testing for 20hz-20k at 8ohms for rated power with all channels around the 80s. Prior to that it was at a single frequency, something like 1k for rated power..which meant about the same as the ratings we get now.

As far as I know, the FTC regulations required testing at 20-20 kHz, at 8 ohms, for 2-channels (all channels until home theater days) ever since 1974. Testing power at 1 kHz, instead of 20-20 kHz, could result in higher power ratings. AVR manufacturers may include ratings like that, but the FTC never required that.

 

[ellisr63]

As far as I know, the FTC regulations, once they were established in 1974, were always the same. In 2007 changes to these regulations were proposed to reflect multichannel AVRs. The FTC ruled in early 2008 to keep the 2-channel requirement as it always was. It would have made more sense to rate all channels driven instead of only 2 channels, but the FTC apparantly decided it had greater problems than audio amplifiers to worry about.

https://www.ftc.gov/sites/default/files/documents/federal_register_notices/trade-regulation-rule-relating-power-output-claims-amplifiers-utilized-home-entertainment-products/080227trade.pdf

As far as I know, the FTC regulations required testing at 20-20 kHz, at 8 ohms, for 2-channels (all channels until home theater days) ever since 1974. Testing power at 1 kHz, instead of 20-20 kHz, could result in higher power ratings. AVR manufacturers may include ratings like that, but the FTC never required that.

It would made more sense IMO to just carry over the amplifier regulations from 2 channel to multichannel instead of taking a step backwards.

Sent from my SM-T830 using Tapatalk

 

[M Code]

As far as I know, the FTC regulations, once they were established in 1974, were always the same. In 2007 changes to these regulations were proposed to reflect multichannel AVRs. The FTC ruled in early 2008 to keep the 2-channel requirement as it always was. It would have made more sense to rate all channels driven instead of only 2 channels, but the FTC apparantly decided it had greater problems than audio amplifiers to worry about.

https://www.ftc.gov/sites/default/files/documents/federal_register_notices/trade-regulation-rule-relating-power-output-claims-amplifiers-utilized-home-entertainment-products/080227trade.pdf

As far as I know, the FTC regulations required testing at 20-20 kHz, at 8 ohms, for 2-channels (all channels until home theater days) ever since 1974. Testing power at 1 kHz, instead of 20-20 kHz, could result in higher power ratings. AVR manufacturers may include ratings like that, but the FTC never required that.

Original FTC power output statue was created in 1973, required a 1 hour preconditioning and then measured power output with 2 channels driven into 8 ohms, @ 20Hz, 1kHz, and 20kHz. But this test was too difficult for the big, high-powered stereo receivers to meet, so actually Pioneer was hit with an FTC Cease & Desist Order that they discontinued their SX-1980. Whose published power output was 270W per channel but actually 165W per channel when measured by the (73) standard....
Marantz was the only receiver brand that actually met the FTC standard into 8 Ohms and 4 Ohms, most brands never even mentioned 4 Ohms. Note the 4 Ohm can be a good indication for real power output.
Next the FTC backed off and left the power disclosure monitoring/challenge to be done by the EIA as multi-channel receivers/products entered the market such as quad...
The EIA technical standards committee made up of Bose, Panasonic and Sony relaxed the standards to 1 channel driven along with the other channels driven @ 1/8 power output. Since more and more products were 7.1 with 7 channels of amplification, it became acceptable to just do 2 channels driven technically equal to 1 channel driven and 6 channels driven @ 1/8 power output.
Since that time 2 channels driven is the defecto standard but now with our global market, internet and Euro standards many brands also quote DIN power which is highly inflated and misleading..
Just comes down to which brand can release and publish the highest number..

Bottom line...
Stay with the established quality brands, read their specs closely and when available check any test reports..

Just my $0.02...

 

[Verdinut]

It would made more sense IMO to just carry over the amplifier regulations from 2 channel to multichannel instead of taking a step backwards.

Sent from my SM-T830 using Tapatalk

With the current surround receiver trend of increasing the number of power amplifiers in the limited chassis size, manufacturers had to sacrifice on the size of the power supply and heat sinks which take a lot of space. In any case, most of the required amplifier power relates to the three front channels, and 50% of the rated power of the front left and right amplifiers is amply sufficient fort he surround channels. For all practical purposes, no Blu-ray soundtrack would require much power for the surround channels simultaneously with the front channels. The only situation where more power is required for the surround channels is when someone uses the all channel stereo feature for which AVRs are not designed to operate at full power.

 

[AcuDefTechGuy]

What about all channel driven power?

Short answer: don't worry about ACD. Why? You won't see a problem in real life.

This is especially true if you set your speakers (all speakers or just the surround speakers) to Small. It means your speakers (set to small) will require about 1 watt of power most of the time.

Example: The KEF Blade has 4 x 9" woofers. Yet even when set to Large Full-Range mode, the Blade required only 1 watt of power most of the time. And then during much louder peak music, it required about 130 watts for about a second. Remember - this is set to Large Full Range mode with four 9" Woofers for each speaker.

So if your speakers are set to small, they are going to need about 1 watt of power, probably less than 1 watt since the big KEF Blade only required about 1 watt of power most of the time for Music Full Range Large.

So long story short, ACD = for bench testing amps, ACD = NOT for Real Life movies/music.

As already been mentioned, some companies will implement very stringent circuit protection to limit power for ACD because we just don't see ACD problems in real life cases - so they do this probably to improve reliability, reduce heat.

Just focus on the 2Ch Driven Power Spec for 8 ohms and 4 ohms, especially if your speakers are 4 ohms nominal.

 

[AcuDefTechGuy]

The only situation where more power is required for the surround channels is when someone uses the all channel stereo feature for which AVRs are not designed to operate at full power.

Well, Yamaha has the 11CH-Stereo DSP on their RX-A3080. And we know how stringent Yamaha's circuit protection is. Yet, we don't see their RX-A3080 shutting down in 11CH-Stereo mode, which is why they offer it.

Otherwise, there might be a lot of lawsuits.

 

[lovinthehd]

Well, Yamaha has the 11CH-Stereo DSP on their RX-A3080. And we know how stringent Yamaha's circuit protection is. Yet, we don't see their RX-A3080 shutting down in 11CH-Stereo mode, which is why they offer it.

At full power with what speakers, tho?

 

[AcuDefTechGuy]

At full power with what speakers, tho?

No, I'm saying Yamaha is not going to allow any significant power to all channels even in their MCH-Stereo mode.

For example, the RX-A880 has 7Ch Stereo Mode. Yamaha would not even offer 7Ch Stereo mode if this will require 7CH ACD Full Power, which would cause the RX-A880 to shut down for sure.

And on another note, if the KEF Blade requires about 1 watt of power most of the time in full range mode, most speakers are not going to require more than the KEF Blade.

 

[lovinthehd]

No, I'm saying Yamaha is not going to allow any significant power to all channels even in their MCH-Stereo mode.

For example, the RX-A880 has 7Ch Stereo Mode. Yamaha would not even offer 7Ch Stereo mode if this will require 7CH ACD Full Power, which would cause the RX-A880 to shut down for sure.

Gotcha, thought you meant you could do such in that dreaded multich stereo mode without shutdown

 

[Swerd]

Original FTC power output statue was created in 1973, required a 1 hour preconditioning and then measured power output with 2 channels driven into 8 ohms, @ 20Hz, 1kHz, and 20kHz. But this test was too difficult for the big, high-powered stereo receivers to meet, so actually Pioneer was hit with an FTC Cease & Desist Order that they discontinued their SX-1980. Whose published power output was 270W per channel but actually 165W per channel when measured by the (73) standard....
Marantz was the only receiver brand that actually met the FTC standard into 8 Ohms and 4 Ohms, most brands never even mentioned 4 Ohms. Note the 4 Ohm can be a good indication for real power output.
Next the FTC backed off and left the power disclosure monitoring/challenge to be done by the EIA as multi-channel receivers/products entered the market such as quad...
The EIA technical standards committee made up of Bose, Panasonic and Sony relaxed the standards to 1 channel driven along with the other channels driven @ 1/8 power output. Since more and more products were 7.1 with 7 channels of amplification, it became acceptable to just do 2 channels driven technically equal to 1 channel driven and 6 channels driven @ 1/8 power output.
Since that time 2 channels driven is the defecto standard but now with our global market, internet and Euro standards many brands also quote DIN power which is highly inflated and misleading..
Just comes down to which brand can release and publish the highest number..

Bottom line...
Stay with the established quality brands, read their specs closely and when available check any test reports..

Thanks for your 2¢!

Still, there is the question of what power ratings should a shopper pay use when comparing different amps or receivers? Most or all AVRs sold in the US publish a list of different power ratings in their owner's manuals. At first look it can be bewildering because of all the different power ratings. I focus only on a power rating that includes words indicating that 2 channels are driven, a frequency range (20 to 20 kHz), a load of 8 ohms, and a defined level of total harmonic distortion (such as 0.08% THD). This rating may include the initials FTC in it. To compare the power of different AVRs or amps, I'd use only those ratings. I'd ignore any other rating type, such as DIN, when 1 channel is driven, when testing only at 1 kHz, or when THD levels higher than 0.1% are mentioned.

I'd also look only in the manufacturer's owner's manual for those specs. Other sources may mistakenly or intentionally get some part of these ratings wrong.