How much power does an AVR deliver in a multi-channel and stereo setup?

[Snoopy8]

This post is now superseeded by 

Background

A question that regularly comes up is how much power does an AVR deliver in a multi-channel setup.  It is not helped by many AVR vendors delivering misleading numbers in their specifications and without any information on multi-channel performance.  To understand how and why AVR companies do this, please have a look at this old but still relevant Audioholics article.

 

In addition to the main question, the following come up as well:

1. Is there an ideal way for reporting multi-channel and stereo power numbers?
2. How to estimate multi-channel power using the total power consumption?
3. What power can a multi-channel amp deliver in a stereo setup?

Will use data from existing equipment to illustrate and support the discussion.  However, I am not technically literate on power amps and welcome input from those who are.

 

An ideal way to report power?

AVR vendors have long abused the lack of a standard for specifying power and do things their own way for marketing. Trying to find an ideal with current AVR power reporting practice is futile.

 

However, it is possible to use a multi-channel amp to find the ideal. A multi-channel amp is a dedicated device, likely to be better designed and have better power components than any AVR. Having accurate power information is essential because the target market is looking for this.  The challenge is to find a product which has both multi-channel and stereo power numbers.  And it should be using only 1 power supply like an AVR.

 

The Emotiva BASX A700 appears to be credible; the specs have RMS (continuous) power, the full frequency range and low THD for both multi-channel and stereo.

 

How does a sample of AVRs compare with this ideal?  Note that all power in tables are for 8 Ohms.

Previously owned MRX-710, now have T768V3.

 

Only Anthem came close to the ideal, but they no longer have the multi-channel power number for their current models. Worse still, Yamaha and Denon specifications also include power numbers for 1kHz, 1 channel driven, 10%THD, which are useless.

How to estimate multi-channel power using the total power consumption?

The Yamaha and Denon AVRs (and many others) do not publish multi-channel power.

 

However, it is possible to estimate that from the power consumption. Sometimes the power consumption is buried in the owner’s manual. Most AVRs have Class AB amps which have about 60% efficiency.  (There are a few AVRs with more efficient Class D amps, but they are outside the scope of this discussion).  But can the 60% efficiency be supported?

 

Again using multi-channel Class AB amps with a single power supply as a reference point.  It is a pity that Emotiva did not publish the power consumption for the BASX A-700.

According to Wikipedia, Class A/B amps are more efficient than Class A (25 to 50%) and below Class B (76%). Audioholics rates Class A/B as between 50 to 70%.  AVRs are built to a budget, so it is unlikely that the Class A/B amps in them are the best and most efficient. Given all that, a 60% efficiency is generous but will use that going forward.

 

Thus, the Yamaha and Denon AVRs with a power consumption of 600W over 7 channels at 60% efficiency can deliver 51W across 7 channels simultaneously. It is a shame that the AVR companies are reluctant to publish such smaller numbers, but the power is enough for many speakers.

 

What about the Marantz 70% Power Guarantee?  Looking at it further here, it applies to 5 channels and Marantz uses Class D amps to achieve this.  Hence, this estimate does not apply to all Marantz AVRs with the guarantee.

 

What power can a multi-channel amp deliver in a stereo setup?

*****

Section removed because new data suggest that multi-channel amp can deliver closer to specs; will update soon...

*****

Recommendations

Read the published power specifications of an AVR carefully. Be especially wary when you see 1 channel driven, 1kHz, 10% THD numbers in the specification; this is a warning that the power specifications are of dubious value. If you want to do a quick compare of AVR power, use the total power consumption as a good proxy. Sometimes the power consumption is buried in the manual.

 

In the absence of a published multi-channel driven power specification, you can estimate that by dividing the total power consumption by the number channels @60% efficiency. 

 

Removed, will update soon.

 

Thank you for taking the time to read this.  Hope this helps you to select an AVR which will give you lots of enjoyment.

 

 

Edited March 17, 2020 by Snoopy8
Superseeded

[Snoopy8]

Data used in the previous post have been reproduced here with both a link and a screenshot (specs can change, disappear).

 

Anthem MRX-710

 

Anthem PVA 7

 

Arcam AVR-550

 

Denon AVR-X3500H

 

Emotiva BASX A700

 

NAD ci 980

 

NAD T758V3 specs

 

Yamaha RX-V1085

 

[gwurb]

2 hours ago, Snoopy8 said:

In the absence of a published multi-channel driven power specification, you can estimate that by dividing the total power consumption by the number channels @60% efficiency. 

 

Unless explicitly stated as continuous or RMS power with full frequency range and low THD, treat the published 2 channel power number for an AVR with caution. To get the estimated power for driving stereo, add 40% to the multi-channel power.

A thing to note is that not all channels will be needing full power all the time. The up side of that is that only the most demanding scenes may struggle for power.

 

2 hours ago, Snoopy8 said:

Arcam AVR-550

 

Arcam, using 1kHz and 0.2% THD numbers, increased from 90W for multi-channel to 125W for 2 channels, about a 40% increase.

 

2 hours ago, Snoopy8 said:

What power can a multi-channel amp deliver in a stereo setup?

 

Using the data that you provide, in particular Arcam as an example (1kHz, 0.2% THD):

When 7 channels are being driven 7*90W=630W. The remaining 870W headroom is available to be used elsewhere.

When 2 channels are being driven 2*125W=250W. The remaining 1250W headroom is available to be used elsewhere.

 

 

Looking at Marantz SR6014 the following is published:

 

There is no way 680W power supply can continuously drive 7 8 ohm speakers at rated power:

110+110 (fronts) + 110 (center) + 110+110 (surround) + 110+110 (surround back): a total of 770 W total just for the channels, plus anything that is required for the rest of the AVR. The wording that Marantz use is rated output. At any point in time any of those channels may be driven to 110W max. Marantz does claim to offer a 70% guarantee so that is suggesting it could be using 539W for the audio channels, leaving 141W for the rest of the amplifier. That may be plausible, leaving only 77W per channel being driven at full power.

If Marantz use a lot of capacitors to store energy for small bursts of high power all channel usage, I do not know. I also don't think that that sort of demand (full power, all channels) would be needed often.

Edited March 15, 2020 by gwurb

[hopefullguy]

from memory my old denon 4311 9.2 avr was once bench tested at...

9xchannel 56w

7x channel 76w

5xchannel 92w

 

irrelevant other than that imo as an avr is not for less than 5.1 anyway

[Snoopy8]

2 hours ago, gwurb said:

 Marantz does claim to offer a 70% guarantee so that is suggesting it could be using 539W for the audio channels, leaving 141W for the rest of the amplifier. That may be plausible, leaving only 77W per channel being driven at full power.

If Marantz use a lot of capacitors to store energy for small bursts of high power all channel usage, I do not know. I also don't think that that sort of demand (full power, all channels) would be needed often.

The 70% guarantee keeps getting repeated. It was based on 1 interview with a Marantz engineer. For all we know it was based on 50% THD??  I am of course making this up, but I do not see this guarantee appearing any where in official material. Marantz is happy that this "fact" continues circulating. It is totally misleading without any supporting data

 

I agree that there is head room available and not all channels demand power simultaneously.  

 

You sound like a troubled Marantz owner by suggesting there is enough power because of headroom and using capacitors to handle bursts of power (I am not a amp engineer, so cannot comment). 

 

I am sorry to cause this angst because it is indeed troubling for people who have bought the marketing story of Marantz and other AVR companies. 

 

I am happy to debate what I have written with someone who has technical knowledge or cite examples similar to what I have done, or cite credible sources that show a different approach to working out what the power is. Even benchmarks like below.

2 hours ago, hopefullguy said:

from memory my old denon 4311 9.2 avr was once bench tested at...

9xchannel 56w

7x channel 76w

5xchannel 92w

 

irrelevant other than that imo as an avr is not for less than 5.1 anyway

Interesting, do you have the source? 

The spec sheet claims 140W for 8 Ohm, 2 CH, low THD.  

 

** Power consumption of 780W by 9 channels @60% = 52W

Edited March 15, 2020 by Snoopy8
Added **

[gwurb]

1 hour ago, Snoopy8 said:

The 70% guarantee keeps getting repeated. It was based on 1 interview with a Marantz engineer. For all we know it was based on 50% THD??  I am of course making this up, but I do not see this guarantee appearing any where in official material. Marantz is happy that this "fact" continues circulating. It is totally misleading without any supporting data

 

I agree that there is head room available and not all channels demand power simultaneously.  

 

You sound like a troubled Marantz owner by suggesting there is enough power because of headroom and using capacitors to handle bursts of power (I am not a amp engineer, so cannot comment). 

 

I am sorry to cause this angst because it is indeed troubling for people who have bought the marketing story of Marantz and other AVR companies. 

 

I am happy to debate what I have written with someone who has technical knowledge or cite examples similar to what I have done, or cite credible sources that show a different approach to working out what the power is. Even benchmarks like below.

The 70% guarantee is from:

https://www.marantz.com/en-gb/shop/avreceiver/sr6014

It's on their website, so I take that to be an official statement. I do not know the THD figure for that guarantee.

 

I do not own SR6014. The closest measured information that I can find on Marantz/Denon products is this:

https://www.audioholics.com/av-receiver-reviews/denon-avr-x3600h

Where the 70% guarantee was exceeded.

 

It is really interesting to read these two forum topics:

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-nad-t758-v3-avr.8912/

https://www.audiosciencereview.com/forum/index.php?threads/denon-avr-x3500h-avr-review.10053/

What I take away from them is that there is no point in having power if its going to lead to distortion. I also take away that some marketing material just doesn't translate to real world, and NAD are liable for that too.

[betty boop]

30 minutes ago, gwurb said:

Where the 70% guarantee was exceeded.

unfortunately only driving 5 channels ? when its  9channel AVR ? we moved beyond 5ch many years ago !  

 

infact for an amp that has 11 speaker terminals to only drive 5 of those channels and guarantee to 70% pretty much says it all  

[betty boop]

31 minutes ago, gwurb said:

What I take away from them is that there is no point in having power if its going to lead to distortion. I also take away that some marketing material just doesn't translate to real world, and NAD are liable for that too.

audio science unfortunately is quite spec / measurement based website, but putting that aside... it is true a great deal of makers ... and id put great majority of them in it. only exceptions ive come across have been specifically nad, rotel, arcam and Cambridge audio... we have lost cambridge audio now though in the AVR stakes. that is not to say other makers AVRS are no good...its just I wouldnt take too much from their spec claims...but defineiyl as go up in their range you do get what you pay for... better power amps stages as with better pre amp, dac, analog stages etc

[hopefullguy]

just from memory i picked up the 4311 results years ago. the thing is its not like the modern avr "computer" doesnt have to do much except reproduce sound.

 

these newer ones make the breakfast and weigh half my denons 18kgs. anyway the front stage is handled by 2xrotels, the denon does the rest...

 

everyone knows the stats are open to interpretation but as long as your running efficient 90+ db ,8ohm speakers it really wont matter will it?

[gwurb]

1 hour ago, gwurb said:

It's on their website, so I take that to be an official statement. I do not know the THD figure for that guarantee.

https://www.marantz.com/en-gb/support/glossary
 

It seems that the 70% is with 0.08% THD.

42 minutes ago, betty boop said:

unfortunately only driving 5 channels ? when its  9channel AVR ? we moved beyond 5ch many years ago !  

 

infact for an amp that has 11 speaker terminals to only drive 5 of those channels and guarantee to 70% pretty much says it all

SR6014 has 9 amplification channels. I don't know what it's performance is like with all 9 channels driven.

 

I know for me I don't need any more than 5 channels so I'd look at their claims. 
 

AudioScienceReview is heavily focused on numbers, but there is something great about that. It's interesting how good or bad Anthem, NAD, Yamaha, Denon, Marantz, others perform on numbers. At times even the 'best' brands simply ride on their reputation without offering a technically better performance.

Edited March 15, 2020 by gwurb

[betty boop]

8 minutes ago, gwurb said:

SR6014 has 9 amplification channels. I don't know what it's performance is like with all 9 channels driven.

680w consumption X 0.6 (efficiency) / 9 = 45wpc I wouldnt expect too much more all channels driven. and if thinking all channels are not driven well guess what in our 3D audio sound fields all channels are indeed driven to create the sound field sand plop things in 3D space.... also thats flat chat nothing to spare... a good reason folks tend to use external amps and subwoofers to lighten the load  

 

9 minutes ago, gwurb said:

AudioScienceReview is heavily focused on numbers, but there is something great about that.

what is also important is how sounds .... great specs in just power doesnt always translate to result you might like. I know i have my own preference ot brands and no matter how good theoretically some are jsut not my cup of tea ... given taste and equipment combination

 

[gwurb]

26 minutes ago, betty boop said:

what is also important is how sounds .... great specs in just power doesnt always translate to result you might like. I know i have my own preference ot brands and no matter how good theoretically some are jsut not my cup of tea ... given taste and equipment combination

Absolutely, I wouldn't buy some brand names based on how they sound: doesn't matter that they have a 'better name'. I'd also be happy to pass on cheaper options that make big claims but don't deliver on sound quality. 

 

26 minutes ago, betty boop said:

and if thinking all channels are not driven well guess what in our 3D audio sound fields all channels are indeed driven to create the sound field sand plop things in 3D space.... also thats flat chat nothing to spare... a good reason folks tend to use external amps and subwoofers to lighten the load

But if there are no speakers connected to the channels then they are not using that power. I won't get the height 3D audio without height speakers. As far as I understand virtual height will only use up to rated power per channel, so that 70% guarantee still applies for 5 channel owners using virtual 3D sound.

I would prefer AVRs that have pre outs as than enables the use of external amps. 

 

I don't think it's worth dismissing an AVR because the producer does not publish all the data. 

[betty boop]

4 minutes ago, gwurb said:

Absolutely, I wouldn't buy some brand names based on how they sound: doesn't matter that they have a 'better name'. I'd also be happy to pass on cheaper options that make big claims but don't deliver on sound quality. 

 

But if there are no speakers connected to the channels then they are not using that power. I won't get the height 3D audio without height speakers. As far as I understand virtual height will only use up to rated power per channel, so that 70% guarantee still applies for 5 channel owners using virtual 3D sound.
 

I think it was mentioned what it will be like with driving 9 channels and hence I responded.

 

if you asked re 5 channels I would have responded as so. re the 70% thing as I mentioned its an utter joke given the 9 channels the amp is able to drive and yet guarantee only cover 5ch ! and only to 70% of claim ! its not also like height channels are just some effects or something either, they do indeed very much get used as do other speakers in the sound field to place objects in space.  its not like the old prologic days 

 

10 minutes ago, gwurb said:

I don't think it's worth dismissing an AVR because the producer does not publish all the data.

no one is dismissing AVRS. its jsut a matter of being realistic about them. I've had gains  with using an external power amp myself in using a very gutsy AVR far more gutsy than the 6014 here being discussed, and even though that AVR could only power 7 channels and the maker was far more honest in publishing data that matched up with power claims. 

 

10 minutes ago, gwurb said:

I would prefer AVRs that have pre outs as than enables the use of external amps. 

and yes for good reason that is why most power amps the ones beyond budget in the range do indeed come with  pre outs,

 

 

[gwurb]

18 minutes ago, betty boop said:

no one is dismissing AVRS. its jsut a matter of being realistic about them. I've had gains  with using an external power amp myself in using a very gutsy AVR far more gutsy than the 6014 here being discussed, and even though that AVR could only power 7 channels and the maker was far more honest in publishing data that matched up with power claims. 

The SR6014 was an easy example to pick as it's widely available, has a lot of technology/features and has pre outs. 
 

I found it hard to get much data on Onkyo or Integra. Pioneer specs look interesting:

 

310W power consumption with 205W x 9ch (6ohm speaker). Class D. I wonder how close it is to the specifications. I would be sceptical.

One of the things I would be curious about in AVR selection is how much is really needed for the buyer. Of course then the speakers, physical space and listening volume come in to affect. If only one could demo a range of AVRs on their own setup, maybe for a week or so at a time.

[betty boop]

1 minute ago, gwurb said:

310W power consumption with 205W x 9ch (6ohm speaker). Class D. I wonder how close it is to the specifications. I would be sceptical.

theyve always been over optimistic to the EXTREME  all class D brings is better efficiency from say 60% upto ~ 90%  

 

0.9x310 / 9 = 31 wpc  

 

that they say 205 wpc and 6 ohm should smell a rat... what THD ? and freq range and is that all channels driven hehe

 

if look other ways 205w x 9 woudl need a 1845w power supply presuming nothing lost in heat  not many AVRs come with that sort of power supplies. usually need to go to external amps for that sort of thing  

1 minute ago, gwurb said:

One of the things I would be curious about in AVR selection is how much is really needed for the buyer. Of course then the speakers, physical space and listening volume come in to affect. If only one could demo a range of AVRs on their own setup, maybe for a week or so at a time.

find a helpfull dealer... might lend you their demo... after have demoed a few options and settled on a choice or two. what will find is while will get you plenty loud... with more power reserves what comes is better clarity, refinement and dynamics all fantastic things that add well to the experience  

[ViVa]

Recently got the NAD Masters M32 and one good reason was their power ratings. What do we make of this?

 

[Snoopy8]

15 hours ago, gwurb said:

The 70% guarantee is from:

https://www.marantz.com/en-gb/shop/avreceiver/sr6014

It's on their website, so I take that to be an official statement. I do not know the THD figure for that guarantee.

You are correct it is official.

16 hours ago, Snoopy8 said:

The 70% guarantee keeps getting repeated. It was based on 1 interview with a Marantz engineer. For all we know it was based on 50% THD??  I am of course making this up, but I do not see this guarantee appearing any where in official material. Marantz is happy that this "fact" continues circulating. It is totally misleading without any supporting data

And I was WRONG!   That inspired me to dig further.

 

From Marantz Glossary

 

All current Marantz AVRs have the 70% Power Guarantee. Looking at 2 of them:

 

Marantz SR5014

100W for 2 channels on the SR5014 will produce 70W for 5 channels based on guarantee. 

Using the power consumption 650W / 7 channels @60% efficiency will give estimated 55W per channel.  This is lower than the guaranteed power but for 7 channels.  7 channels will undoubtedly reduce the available power but by how much?

 

Marantz NR1510

50W for 2 channels will give 35W for 5 channels based on guarantee.

With 210W power consumption for 5 channels @60% efficiency, estimated power is 25W per channel.  Again, lower than guaranteed power, but this time for the same number of channels.

 

It appears that the NR1510 can do at least 83% efficiency (5x35W divided by 210W power consumption) which suggest that Marantz is not using Class AB amps which cannot exceed the efficiency of Class B at 78%.  This is likely Marantz  HDAM which I will read further.

 

Interesting.  Will revise my original post to include this.

 

[Snoopy8]

10 hours ago, ViVa said:

Recently got the NAD Masters M32 and one good reason was their power ratings. What do we make of this?

 

It is fine and a nice box.  

 

Generally, stereo power specs are truthful.  It is AVR power specs which is the problem and my focus in this thread.

[gwurb]

4 hours ago, Snoopy8 said:

It appears that the NR1510 can do at least 83% efficiency (5x35W divided by 210W power consumption) which suggest that Marantz is not using Class AB amps which cannot exceed the efficiency of Class B at 78%.  This is likely Marantz  HDAM which I will read further.

HDAM is either A/B or B. I had a look at some schematics online but didn't look hard enough to consider biasing. It's FETs used for buffering instead of op amps. The justification is that op amps are noisier.

 

I think NR series are not A/B. They don't have HDAM.

[Snoopy8]

4 minutes ago, gwurb said:

HDAM is either A/B or B. I had a look at some schematics online but didn't look hard enough to consider biasing. It's FETs used for buffering instead of op amps. The justification is that op amps are noisier.

 

I think NR series are not A/B. They don't have HDAM.

Can you tell if it is Class D?  That is the only way the the slim line can have such efficiencies.  I also think an Onkyo high end model is Class D with only 320W of power consumption but getting some high power.  Are there other classes I should look at?

 

Also, I am re-writing my original post because of new data that I have found that totally invalidates  some of my earlier thoughts. 

[gwurb]

19 hours ago, Snoopy8 said:

Can you tell if it is Class D?  That is the only way the the slim line can have such efficiencies.  I also think an Onkyo high end model is Class D with only 320W of power consumption but getting some high power.  Are there other classes I should look at?

 

Also, I am re-writing my original post because of new data that I have found that totally invalidates  some of my earlier thoughts. 

I have only found that the NRxxxx don't use HDAM. One of a few places that talk about it:

https://www.avsforum.com/forum/90-receivers-amps-processors/3074034-official-2019-marantz-nr-series-sr-series-avr-owner-s-thread-faq-posts-1-6-a.html

 

As far as classes go here is a quick rundown of the different classes:

https://www.audioholics.com/audio-amplifier/amplifier-classes

Marantz could be using G, H or D. I would think that they would not be using A/B in the NRxxxx as it can't give them the 70% guarantee. It would most likely be D as it's common. I have read that someone used G in their product but it is uncommon. I would give them some credit as they have a reputation to uphold. I may be wrong about credit and reputation

Edited March 17, 2020 by gwurb

[Snoopy8]

3 minutes ago, gwurb said:

I have only found that the NRxxxx don't use HDAM. One of a few places that talk about it:

https://www.avsforum.com/forum/90-receivers-amps-processors/3074034-official-2019-marantz-nr-series-sr-series-avr-owner-s-thread-faq-posts-1-6-a.html

 

As far as classes go here is a quick rundown of the different classes:

https://www.audioholics.com/audio-amplifier/amplifier-classes

Marantz could be using G, H or D. I would think that they would not be using A/B as it can't give them the 70% guarantee in the NRxxxx line. I would give them some credit as they have a reputation to uphold. I may be wrong about credit and reputation

Thank you for searching.  I was surprised that the slimline NR range was included in the guarantee.  Everyone else's slim AVRs are a disaster with power, a case of form over functionality. 

 

It will be nice to know what class they are, but does not change what I have to say with a revised version of this thread.  Some interesting things backed by data and I made a few wrong assertions earlier.  Will be out soon...

[surprisetech]

1 hour ago, gwurb said:

I have only found that the NRxxxx don't use HDAM. One of a few places that talk about it:

https://www.avsforum.com/forum/90-receivers-amps-processors/3074034-official-2019-marantz-nr-series-sr-series-avr-owner-s-thread-faq-posts-1-6-a.html

 

As far as classes go here is a quick rundown of the different classes:

https://www.audioholics.com/audio-amplifier/amplifier-classes

Marantz could be using G, H or D. I would think that they would not be using A/B in the NRxxxx as it can't give them the 70% guarantee. It would most likely be D as it's common. I have read that someone used G in their product but it is uncommon. I would give them some credit as they have a reputation to uphold. I may be wrong about credit and reputation

NR1501 & NR1508 are Class AB, so the others in  between those models probably are too.  I've got schematics for the 1501 & 1508.  

Not sure about the newer 1509 & 1510.

I'm only driving the Centre & Surrounds with my 1508 and very happy with it's performance.  Power available to each speaker would be very close to the rated 50W RMS given that I'm only driving 3.

[gwurb]

11 minutes ago, surprisetech said:

NR1501 & NR1508 are Class AB, so the others in  between those models probably are too.  I've got schematics for the 1501 & 1508.  

Not sure about the newer 1509 & 1510.

I'm only driving the Centre & Surrounds with my 1508 and very happy with it's performance.  Power available to each speaker would be very close to the rated 50W RMS given that I'm only driving 3.

Could you post the schematics please?

[Snoopy8]

I have updated the original post which had inaccurate info and wrong advice.  I am now using independent Test Bench data from Sound & Vision who measured 2, 5 and 7 channels!  That has forced me to change my views on AVR power.