ALL-Channel driven simultaneously power tests anyone?

[jeannot]

PENG, OMG. They even tested my receiver.
Exactly what I was looking for.
Thank you, thank you, thank you.

 

[M Code]

Here you go, enjoy, and don't forget to write us a book report.......

http://www.hometheater.com/content/denon-avr-3808ci-av-receiver-ht-labs-measures

http://www.hometheater.com/content/pioneer-elite-sc-37-av-receiver-ht-labs-measures

http://www.hometheater.com/content/nad-t-747-av-receiver-ht-labs-measures

http://www.hometheater.com/content/denon-avr-4310ci-av-receiver-ht-labs-measures

http://www.hometheater.com/content/integra-dtr-99-av-receiver-ht-labs-measures

http://www.hometheater.com/content/yamaha-rx-z11-av-receiver-ht-labs-measures

There are some British ones:

http://hcc.techradar.com/reviews_archive?filter0=142&filter1=&filter2=

Looks like the power output measurements were done @ 1kHz..
What about 20Hz and 20kHz..
1kHz poses little challenge to an amplifier & power supply..

Just my $0.02...

 

[PENG]

Then, I would have returned the courtesy by answering that two amplifiers may give the same power in stereo, but one of them half that in 7 channel mode because the manufacturer skimped on the power supply. That can also be an indication that they also may be skimped on the output transistors SOA, display and relays MTBF, etc... The weight, power consumptions are other indicators but I believe they are more debatable.

You made a good point and your thinking is logical. However, based on my own observations over the years reading reviews, the contrary tend to be true. For example, you will find that Denon, Onkyo, Yamaha, Marantz, Pioneer, especially Yamaha typically tested very well on the bench in 1 and 2 channel outputs into 8 and 4 ohms while not so good in 5 and ACD. NAD and HK, especially HK, would test well in 5 ch and ACD, but only relative to their published specs while not doing so well in 1, 2 channel tests into 8 and 4 ohms.

For example, if you read up on the bench test results of comparable NAD, HK and Yamaha AVRs you will see that quite often the Yamaha's 1,2 channel outputs exceed their published specs by as much as 30% (8 ohms) to 50% (4 ohms) whereas the NAD and more so HK will have 1,2 channel tested outputs only slightly higher than their published specs with 5,7 channel outputs slightly lower.

I can't help but to think that NAD (not so much) and HK (more so) might have put more money in the power supplies while skimped on the amp section such as the output devices. This is contrary to our logical thinking. If we think deeper, it can actually be logical though because let's say the manufacturer has a budget of $1000 to spend on the power supply and the amps, if you spend more on one you are forced to skimp on the other. If you spend more on both then you have to sell your products for more. HK has to compete hard with the others in big box stores so they can't affored to sell their products for more. NAD can, and that's why they tend to do better on power supply yet still hold their own on the amp section.

You can see at least one highly representative example of my points if you read the HTM reviews on the Denon 3805 and HK 630. For more recent example, you will also find that the Denon 3808 showed some impressive 1,2 channel outputs into 8 and 4 ohms. You won't find any HK or NAD AVR that beats it except for their flag ship models. In fact the 3808 had some impressive ACD outputs too, and new model such as the 4810 has a huge power supply transformer and caps in it but tested poorly in ACD but that is no reflection on their PS being the limiting factor. It has more to do with the way their protective circuit operates. Their latest model, the 4311 claimed 4 ohms capable so I can't wait to see how well they do in ACD.

 

[PENG]

Looks like the power output measurements were done @ 1kHz..
What about 20Hz and 20kHz..
1kHz poses little challenge to an amplifier & power supply..

Just my $0.02...

For 20 to 20,000 Hz I expect the numbers would drop. Not sure by how much, probably 10 to 15% based on what I read before when they did both. Still, that's just my educated guess, what do you think? As always, I value your opinion, knowing that you have the advantage of being an insider.

 

[PENG]

PENG, OMG. They even tested my receiver.
Exactly what I was looking for.
Thank you, thank you, thank you.

Sorry man, I didn't notice you have a 3808. I have A/B my 4308 with my 4 power amps many times and I can tell you in two channel applications the 4308 sounded just as powerful as the 300WPC one but that's because in my 12X20X8 room I only listened at around 85 dB with <100 dB peaks maximum. Any louder I would have to wear ear plugs.

 

[M Code]

For 20 to 20,000 Hz I expect the numbers would drop. Not sure by how much, probably 10 to 15% based on what I read before when they did both. Still, that's just my educated guess, what do you think? As always, I value your opinion, knowing that you have the advantage of being an insider.

You can't quote specific %s' as it really depends upon the AVR's cost, brand and design components.. For example, if the power supply has been costed down, with smaller capacitors and transformer power output @ 20Hz could be down 30-40%..

But I think 10-20% could be applied as a general rule..

Just my $0.02..

 

[mike c]

thanks for the links PENG.

nice to see the 3808 measure nicely against the 4310 and 4810.
even when i buy a new AVR for the updated surround features, i'll keep the 3808 for a future 2.1 or 3.1 setup.

it's too bad they haven't tested any of the new HK's. i'm interested in the HK3600's looks.

 

[PENG]

You can't quote specific %s' as it really depends upon the AVR's cost, brand and design components.. For example, if the power supply has been costed down, with smaller capacitors and transformer power output @ 20Hz could be down 30-40%..

But I think 10-20% could be applied as a general rule..

Just my $0.02..

That makes a lot of sense, thanks again.

 

[PENG]

thanks for the links PENG.

nice to see the 3808 measure nicely against the 4310 and 4810.
even when i buy a new AVR for the updated surround features, i'll keep the 3808 for a future 2.1 or 3.1 setup.

it's too bad they haven't tested any of the new HK's. i'm interested in the HK3600's looks.

You are welcome Mike. I have had those links saved and I did do an excellent spreadsheet for quick comparsion of specs.

I bet you a lot of owner don't even know how good the 3808 is. If I had read that review I would have save a few hundred bucks and bought the 3808 instead of the everything gold plated 4308. The 3808 not only tested well in terms of power, it also had very impressive cross talk numbers, in the high 80's. That is much better than even the 4810 and at least as good as or slightly better than the newer Marantz separate prepros/amps.

 

[mike c]

You are welcome Mike. I have had those links saved and I did do an excellent spreadsheet for quick comparsion of specs.

I bet you a lot of owner don't even know how good the 3808 is. If I had read that review I would have save a few hundred bucks and bought the 3808 instead of the everything gold plated 4308. The 3808 not only tested well in terms of power, it also had very impressive cross talk numbers, in the high 80's. That is much better than even the 4810 and at least as good as or slightly better than the newer Marantz separate prepros/amps.

was just thinking of doing a spreadsheet, but my laziness won

which receivers did you input into your spreadsheet? want to share a screenshot of it?

yeah, the 3808 really was a bang for the buck. i currently use it with power amps (except for the surrounds) though.

 

[jeannot]

You made a good point and your thinking is logical. However, based on my own observations over the years reading reviews, the contrary tend to be true. For example....

I skipped a long quote...

About 2 vs 5 channel performance, I would say that a receiver giving 50% more power in 2 channel than in 5 is actually a backwards way of looking at it. Reality is, it gives 33% poorer performance in ACD than in 2 channel, indicating a mediocre power supply.

I will not go in the technical stuff, but the ideal power supply will give the amp about the same power in 2 or 7 channels modes. Thus, the difference in power between these 2 modes is a measure of the poor quality of the power supply. That is why some high-end amps have separate power supplies per channel.

The other issue is that because the measurements are made on resistive loads, they are not representative of how the amp handles the inductive speaker loads, which can be equivalents to between 3 and 50 ohms, and a lot of electrical/mechanical difficulties. The ACD tests are an indication of at least how the power supply will handle these low impedances.

 

[avnetguy]

About 2 vs 5 channel performance, I would say that a receiver giving 50% more power in 2 channel than in 5 is actually a backwards way of looking at it. Reality is, it gives 33% poorer performance in ACD than in 2 channel, indicating a mediocre power supply.

Guess it depends on how you look at it. For example, if a receiver gives more than it's rated output over two channels and meets the stated output for normal program material on 5 channels but falls short under ACD, that indicates it has a good (non over engineered) power supply.

Steve

 

[TLS Guy]

I must say I find this thread a little strange.

A receiver is at its essence built to a price consumer gear with compromises you would expect.

You have heat and space limitations. The plug in the wall is a limitation.

So where do you need the power generally? Its the front right and left, the center as well. However there are usually space constraints on the center, and therefore another inherent compromise.

The surround channels with most sources are called to deliver little power and in most receiver systems are more often than not puny miserable speakers.

Now a big power supply will take up a lot of the space. So that would push me in the direction of limiting the power supply and current.

The amps in receivers usually have a close spaced small output devices. You don't want them all heating up at once. Limiting current and power therefore likely contributes to extend life before it an output device fails and the receiver goes into continuous reset.

I don't think you should consider any receiver for a reference system. If that is what you are trying to build, the get a pre/pro and good power amps.

When it comes to testing I know of very few amps tested with varying phase angles just resistive loads.

Even when you design a reference system, it probably is not wise to design for equal power to all speakers.

For instance I allowed 750 watts for each main, and 500 watts for the center.

I allowed 100 watts for each surround, and 200 watts for each rear back. However that was because the surrounds and rear backs where from legacy systems and the speakers too good to put out to pasture.

Only a few of my SACDS really make heavy demands on the rear backs. (Those are the correct speakers to use for European mastered SACDs).

So the bottom line is that if you want to play the Aho symphony No 12 with Laplanders hitting huge drums hard all the way round the room it will cost you.

So you do have to judge a device for the purpose intended. Receivers are by their designers intent limited and compromised, and that is the only practical solution.

 

[PENG]

was just thinking of doing a spreadsheet, but my laziness won

which receivers did you input into your spreadsheet? want to share a screenshot of it?

yeah, the 3808 really was a bang for the buck. i currently use it with power amps (except for the surrounds) though.

I have to apologize again. I meant to say I did an Excel (not "excellent") spreadsheet.

I listed a bunch of AVR HTM lab measurements that included cross talks, S/N, 2 channel output into 8, 4 ohms, 5,7 ch into 8 ohms etc. Unfortunately I have since replaced my desktop and laptops so I have to search through my back up drives, USB thumb drives etc. If I can't find it I can quickly do another one. I am pretty quick on spreadsheets. Even if I find that sheet I have to add the new ones to it. Another weekend project for sure.

 

[3db]

I must say I find this thread a little strange.

A receiver is at its essence built to a price consumer gear with compromises you would expect.

You have heat and space limitations. The plug in the wall is a limitation..

That same plug limitation also limits seperates.

So where do you need the power generally? Its the front right and left, the center as well. However there are usually space constraints on the center, and therefore another inherent compromise.

The surround channels with most sources are called to deliver little power and in most receiver systems are more often than not puny miserable speakers.

Now a big power supply will take up a lot of the space. So that would push me in the direction of limiting the power supply and current.

The amps in receivers usually have a close spaced small output devices. You don't want them all heating up at once. Limiting current and power therefore likely contributes to extend life before it an output device fails and the receiver goes into continuous reset..

Not all receivers are of this ilk. Take a serious look at NAD and you may walk away with a different outlook. There are very few instances where you need full power across all channels and one can offset this by using power amps for the two channels by using teh receiver as a pre-amp. The pre-amps found in the higher end Yamaha's have better SNR ratios then some of the megabuck seperates out there.

 

[PENG]

I skipped a long quote...

About 2 vs 5 channel performance, I would say that a receiver giving 50% more power in 2 channel than in 5 is actually a backwards way of looking at it. Reality is, it gives 33% poorer performance in ACD than in 2 channel, indicating a mediocre power supply.

I will not go in the technical stuff, but the ideal power supply will give the amp about the same power in 2 or 7 channels modes. Thus, the difference in power between these 2 modes is a measure of the poor quality of the power supply. That is why some high-end amps have separate power supplies per channel.

It seems to me we are almost saying the same thing differently. Given a budget you either skimp on the P/S or on amps. Some choose to put the money on amps so there is a greater chance of doing better with most (not all) real world material such as movies, jazz and classical music while others would put in stronger P/S and save money on output devices so they will do better on certain real world material such as rock concerts that typically has a lot of contents in all 7 channels, but will provide less power and lower dynamics for 2 channel applications as well multi channel applications that do not have much continuous contents in the surround channels. As consumers we have to choose one but cannot have both. If you need both relatively higher power for 2 and all channels, then you need to spend more money on separates or flag ship AVRs. Any non flag ship AVRs are expectedly products of compromise.

 

[PENG]

That same plug limitation also limits seperates.



Not all receivers are of this ilk. Take a serious look at NAD and you may walk away with a different outlook. There are very few instances where you need full power across all channels and one can offset this by using power amps for the two channels by using teh receiver as a pre-amp. The pre-amps found in the higher end Yamaha's have better SNR ratios then some of the megabuck seperates out there.

I would like to respectfully debate you to the nth degree on this but I will not do so out of respect so I will only do this once. If you could, please show me lab measurements of some NAD AVRs aside from their flag ship models that compare favorably to that of a mid range Denon AVR3808, 4310 or Onkyo 805, 875, 905/6, or Pioneer Elite SC37. As far as I know their flag ship models are not any more powerful than Denon 5805, 5308, or Yamaha RX-Z11 but again if you could me lab measurement that shows otherwise then I must be wrong.

I know NAD makes great amps, and I almost bought one but found a great deal on an Anthem in the last minute but I do feel that there are lots of near myths and hearsays out there about NAD and HK about their power outputs. Their AVRs are still just AVRs, just because they know how to make great amplifiers does not make their AVR better than the popular Denon, Yamaha, Pioneer models. They has to compete, and in doing so they also compromise. And please don't remind me of their so called dynamic power into 2 ohms and their deal weight. I don't put much faith in those numbers unless they fully define "dynamic".

 

[M Code]

Guess it depends on how you look at it. For example, if a receiver gives more than it's rated output over two channels and meets the stated output for normal program material on 5 channels but falls short under ACD, that indicates it has a good (non over engineered) power supply.

Steve

1 general statement does not apply to all price levels of AVRs..
For example...
In the entry level category when the SRP is <$699, the amount of power supply (current & voltage) available is limited.
So if the amplifier is rated @ 2-Channels driven (100W x 2) into 8 Ohms when 5-channels are driven it will output 40W x 5 as the AVR only has 200W of total capability based upon power supply current/voltage availability.

As one goes into higher priced AVR categories, this may change somewhat as the power supplies are designed with heavier duty components. Plus they frequently will use some type of regulation which tends to balance out the power available.

Regarding NAD AVRs, since we were involved in some of their technical development for certain models I actually have the entire amplifier measurements archived.

Just my $0.02...

 

[3db]

I would like to respectfully debate you to the nth degree on this but I will not do so out of respect so I will only do this once. If you could, please show me lab measurements of some NAD AVRs aside from their flag ship models that compare favorably to that of a mid range Denon AVR3808, 4310 or Onkyo 805, 875, 905/6, or Pioneer Elite SC37. As far as I know their flag ship models are not any more powerful than Denon 5805, 5308, or Yamaha RX-Z11 but again if you could me lab measurement that shows otherwise then I must be wrong.



I know NAD makes great amps, and I almost bought one but found a great deal on an Anthem in the last minute but I do feel that there are lots of near myths and hearsays out there about NAD and HK about their power outputs. Their AVRs are still just AVRs, just because they know how to make great amplifiers does not make their AVR better than the popular Denon, Yamaha, Pioneer models. They has to compete, and in doing so they also compromise. And please don't remind me of their so called dynamic power into 2 ohms and their deal weight. I don't put much faith in those numbers unless they fully define "dynamic".

I should have said flagship AVRs and which I had in mind when I said NAD.

I'm tired of the same old compromise statement touted by TLS. I understand that seperates will offer better perfomance in terms of power but not all seperate pre-amps can match the SNR of preamps of AVRs so where is the compromise there. Unless the room is a hall driving some really high reactive loads with phase angles greater than 45 degrees, I don't see the compromise personally. Level matched and within the capabilities of a receiver, I doubt very much that one could tell between seperates and a receiver.

 

[PENG]

I should have said flagship AVRs and which I had in mind when I said NAD.

I'm tired of the same old compromise statement touted by TLS. I understand that seperates will offer better perfomance in terms of power but not all seperate pre-amps can match the SNR of preamps of AVRs so where is the compromise there. Unless the room is a hall driving some really high reactive loads with phase angles greater than 45 degrees, I don't see the compromise personally. Level matched and within the capabilities of a receiver, I doubt very much that one could tell between seperates and a receiver.

I think separates to him means serious separates. I totally agree with you on this. As a matter of fact, I have the Marantz pair AV7005/MM8003 that actually offer less power than flag shop models of Denon, Yamaha, Pioneer and NAD. As crazy as it sounds, I did not buy the pair for power. If I did I would have picked up one of those flag ship AVR I mentioned and be done with it.