Help understanding Harman/Kardon AVR power ratings

[mtrycrafts]

Looks like they can in two channel according to Home Theater Mag's measurements, but not in 5 channels. in the Pioneer 1019 review, looks like distortion starts setting in at 34.3 watts per channel, 5 channels driven. And when they measured the Sony 5400ES, which I've tried using and rather liked), it started distorting at 45 wpc, 5 channels driven. However, it's two-channel power seemed to measure higher than stated and pretty boss

Well, those companies didn't advertise them with 'all' channels driven power but the current FTC standards and they seem to put out more for that claim. I think that is what matters more so.

 

[valvesnvinylfan]

Definitely agreed. Just trying to say that, overall, it's nice when we can see more measurement specs on receivers/amps; I just wish there were more published specs out there--from other review mags, 3rd party sources, etc.--when it comes to power delivery. I will also say, as far as the original topic of this thread goes, I've owned a couple of H/K AVRs in the recent past and thought they always seemed to have more power on tap then the specs would lead you to believe.

 

[PENG]

I've owned a couple of H/K AVRs in the recent past and thought they always seemed to have more power on tap then the specs would lead you to believe.

Sure, if their specs say 50 and you get bench tests routinely showing 80X2, 5X50 and 7x45, you should definitely think that way but at the end of the day you may get more from your Sony that you pay about the same money for. Another factor is that over various forums you have people telling you the same thing over and over again that HK typically puts out more real power than what they show on paper. That, I suspect, may have prepared you psychologically to think that way also.

Now let's look at something objectively. The fact is that bench tests cannot be taken to the bank either, as the test results may depend on how the tests are conducted. For example, when they do ACD test, do they always hold the power supply voltage constant, or do they simply let it drops as the current demand increases during the ACD and/or low impedance tests?

You cited the poor ACD showing of your Sony ES in the HT mag test but if you take a look of the bench tests done by the British, e.g. the H.C.C. you may be happier with your Sony because even a non ES model came up with decent numbers (5X112W into 8 ohms at 0.5% THD).

http://www.homecinemachoice.com/reviews/new_reviews/sony+str+dg820+av+receiver+24+11+08

http://www.homecinemachoice.com/reviews/reviews_archive/Sony+AV+Receiver+-+STR-DA5300ES

The 5300ES actually managed 5X126W into 4 ohms, 5X112W into 8 ohms, 2X140W into 8 ohms, fidelity firewall 125W!! It beats the 40 lb+ HK AVR635 in all categories of tests!!!

http://www.homecinemachoice.com/node/6012

HKAVR635: 5X125W into 4 ohms, 5X90W into 9 ohms, 2X90W into 8 ohms, fidelity firewall 100W into 8 ohms.

By the way, some British magazines including the HCC and WhatHifi also tend to rate Sony higher or equal to the NAD most of the time, yet NAD is thought of at least two notches higher than Sony here in NA. I tend to pay less attention to reports/reviews based on perception and opinion and pay more attention to technical specifications that are supported by properly conducted lab measurements and other physical factors.

 

[valvesnvinylfan]

Sure, if their specs say 50 and you get bench tests routinely showing 80X2, 5X50 and 7x45, you should definitely think that way but at the end of the day you may get more from your Sony that you pay about the same money for. Another factor is that over various forums you have people telling you the same thing over and over again that HK typically puts out more real power than what they show on paper. That, I suspect, may have prepared you psychologically to think that way also.

Now let's look at something objectively. The fact is that bench tests cannot be taken to the bank either, as the test results may depend on how the tests are conducted. For example, when they do ACD test, do they always hold the power supply voltage constant, or do they simply let it drops as the current demand increases during the ACD and/or low impedance tests?

You cited the poor ACD showing of your Sony ES in the HT mag test but if you take a look of the bench tests done by the British, e.g. the H.C.C. you may be happier with your Sony because even a non ES model came up with decent numbers (5X112W into 8 ohms at 0.5% THD).

http://www.homecinemachoice.com/reviews/new_reviews/sony+str+dg820+av+receiver+24+11+08

http://www.homecinemachoice.com/reviews/reviews_archive/Sony+AV+Receiver+-+STR-DA5300ES

The 5300ES actually managed 5X126W into 4 ohms, 5X112W into 8 ohms, 2X140W into 8 ohms, fidelity firewall 125W!! It beats the 40 lb+ HK AVR635 in all categories of tests!!!

http://www.homecinemachoice.com/node/6012

HKAVR635: 5X125W into 4 ohms, 5X90W into 9 ohms, 2X90W into 8 ohms, fidelity firewall 100W into 8 ohms.

.

Sure, I definitely agreee--seems like nowawdays one can tailor tests for practically anything to support one's claim. And voltage droop will definitely be a factor that affects amplifier power ratings, but I think this is an important to consider; after all, how many folks actually have a $1k+ voltage stabilizer or other such device at home, especially if they have a receiver like the Pioneer 1019 at an MSRP of $500? I have read in some mags that they will test their amps with a Variac, but it could be argued that letting the voltage sag may closer simulate real world conditions the user is likely to experience.

(Note: I think I missed something though; the 820 you're citing here measured 78W x 5 channels driven, 4 ohms, 0.5% THD; the claim was 100 x 7 into 4).

I agree, the Sony ES beat the H/K, but barely, according to the measurements you cited; moreover, it's important to note that the manufacturer's rating for the H/K 635 is 75 watts per channel, the Sony 5300's claimed power into 8 ohms is 120 watts, while the measured into 8 ohms was 115, 5 channels driven, another case where the H/K exceeded it's rated output, which was my original point.

 

[mtrycrafts]

..., but it could be argued that letting the voltage sag may closer simulate real world conditions the user is likely to experience.

.

Certainly in the vast majority of cases it would be real world experience. But, then, one home may be getting 125V before the sag and the next may be getting only 120 and mine would only sag to 120 at the high power demands.
Cannot account for everything but, yes, more realistic.

 

[PENG]

(Note: I think I missed something though; the 820 you're citing here measured 78W x 5 channels driven, 4 ohms, 0.5% THD; the claim was 100 x 7 into 4).

As far as I know Sony typically does not make any claims on ACD rating let alone 4 ohms so please show me where you get that 100X7 into 4 claim by them.

it's important to note that the manufacturer's rating for the H/K 635 is 75 watts per channel, the Sony 5300's claimed power into 8 ohms is 120 watts, while the measured into 8 ohms was 115, 5 channels driven, another case where the H/K exceeded it's rated output, which was my original point.

I understood your point and I agree with you. On the other hand, it is also important to note that on a $/Watt (power output verified by credible bench tests such as those by HCC mag) basis HK does not do too well against products in the same price group such as those from Denon, Onkyo (800/900 series), Yamaha, especially if you are in Canada, where they are sold routinely at or close to the list prices. That is not to say they don't have other superior qualities.

 

[valvesnvinylfan]

Actually, it was right there in the Home Cinema Choice article you linked; here's the quote/their numbers:

Tech Labs
Manufacturer’s specifications: 100W
x 7 channels (into 4 ohms)
102W (2 channels driven, 8 ,
0.5% THD)
136W (2 channels driven, 4 ,
0.5% THD)
70W (5 channels driven, 8 ,
0.5% THD)
78W (5 channels driven, 4 ,
0.5% THD)
Fidelity firewall:
95W (0.02% THD, 8 , 1kHz)
THD @ 50W: 0.0074% THD
(1kHz, 8 )
Frequency response 20Hz-
20kHz: +/- 0.36dB

Still, I also agree with you on much of what you said, and I have always thought the Sony 820 and the 5300ES to be good receivers--especially in two channel, which HCC liked as well. But to say the H/Ks don't perform as well is definitely up to interpretation. If total wattage is the only concern, then I would have to agree with you, as the Sony 5300es that you cited in particular is higher in wattage (just barely in multichannel mode though). However, H/Ks often have higher current delivery within their wattage specs than many receivers out there with even double the claimed wattage; and I'm sure you're aware current delivery will be a more important factor then voltage when it comes to driving speakers with more severe impedance or phase angle curves.

My original point was about how many manufacturer's omit accurate, bench-tested ACD (or even 5 channels driven)power figures, leading the consumer to assume they're just as powerful in multi-channel mode. I get many customers every day who aren't as knowledgeable as you or other forum members here; who believe claimed power specs to always be true and directly apply to multichannel modes as well because they don't understand all the variables or different testing procedures. I always try to point them to forums like these, but I'm sure there are many others who aren't aware.

 

[PENG]

Actually, it was right there in the Home Cinema Choice article you linked; here's the quote/their numbers:

Tech Labs
Manufacturer’s specifications: 100W
x 7 channels (into 4 ohms)

Thanks, I missed that one, but I think it might have been a typo. Please check out:

http://www.sony.co.uk/product/hcs-home-cinema-receiver/str-dg820/tab/technicalspecs

However, H/Ks often have higher current delivery within their wattage specs than many receivers out there with even double the claimed wattage; and I'm sure you're aware current delivery will be a more important factor then voltage when it comes to driving speakers with more severe impedance or phase angle curves.

Again, I fully agree with your reasoning but HK simply specifies high instantaneous current while others choose not to bother providing yet another number that is vague at best if not totally meaningless. I mean, what is instantaneous, 1 micro second, or 1 millisecond, who knows? In fact if you look at their 4 ohm bench test results you will come to my same conclusion that HK models cannot sustain high current. I would not recommend any of the current HK models for 4 ohm speakers regardless of their phase angle vs frequency curves. Remember the S&V lab test in which the AVR-330 activated the protection mode when asked to produce only 25W into 4 ohms? How is that high current?

That being said, if you want to talk about the power/current ratings of some of their older killer models such as the AVR7200 and 7300, I will be in full agreement with you. I consider those models truly high current capable and that they were among the most powerful receivers at any price in their time.

 

[valvesnvinylfan]

Ahh, yes--I used to own the H/K 7200. Gawd, I loved it! I must admit I haven't seen many of the newer H/Ks, but I don't doubt you concerning their abilities; the 635 was one of the last ones I took apart and looked at from them. Pretty good design, too--high voltage rails, multiple nice sized caps, and one massive xformer. I will say though that the Onkyo 875 I have now is a beast--independent power supplies with huge transformer and caps. There was a while there when Onkyo couldn't do wrong. The 805 had almost the same amp section as the 875; now the 806 or whatever is pretty much like the 706 in terms of it's amp--i.e. not very beefy. And only the 5007 in the new"00" receivers have the toroidal xformer. But that's for another thread.

 

[PENG]

There was a while there when Onkyo couldn't do wrong. The 805 had almost the same amp section as the 875; now the 806 or whatever is pretty much like the 706 in terms of it's amp--i.e. not very beefy. And only the 5007 in the new"00" receivers have the toroidal xformer. But that's for another thread.

Purely from power stand point your 875 is among the few receivers that are quite comparable to the 7200 so of course it can do no wrong. I hope you are bragging not complaining.

 

[valvesnvinylfan]

No, not complaining at all (hopefully not bragging either though!)--but I do very much love the 875

 

[PENG]

No, not complaining at all (hopefully not bragging either though!)--but I do very much love the 875

But you do have the bragging right you know that? I wish I had the 875 or 905 instead of the 4308. If I had the Onkyo I wouldn't have bothered hooking it up to an external amp that takes up rack space. I also wish HK would eventually come out with an up to date 7.1 receiver that is as powerful as the 7300.