Receiver Power Ratings Game

[gene]

Article coming tomorrow

 

[Polkfan]

Lookin' forward to it!

 

[gene]

<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><A href="http://www.audioholics.com/techtips/audioprinciples/amplifiers/receiverpower.php"><IMG style="WIDTH: 125px; HEIGHT: 77px" alt=[powercurve2] hspace=10 src="http://www.audioholics.com/news/thumbs/powercurve2_th.jpg" align=left border=0></A>We have been receiving numerous requests from our forum members to compare sonic and power differences between receivers at comparable price points, both from different brands and / or different model generations from the same brand and product line.<SPAN style="mso-spacerun: yes">&nbsp; </SPAN>The truth be told is aside from new added features of the latest and greatest offerings, there are usually minor discernable fidelity and overall output power output differences when comparing receivers of similar price from the top competitors.&nbsp; In this article you will findout how many companies derive their power specifications and why the "All Channels Driven Test" (an unrealistic test scenario as it is typically conducted) falls apart in these cases.&nbsp; Check out Patrick’s take on this topic; whose background includes serving as Product Manager for many of today’s top receiver brand offerings.&nbsp; </SPAN></P>
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<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">[Product Managing Receiver Platforms &amp; Power Ratings]</SPAN></P>

 

[plhart]

Hey Gene-

You're right. Not one response to my article. Hmmm, do ya think I squashed another super lengthy thread and answered every possible question on power ratings because I told the truth? Oops, almost forgot. That's our Audioholics motto....

 

[gene]

Pat;

I think people are more interested in debating the magic of exotic cables

 

[FLMike]

Great Article

plhart,
Really enjoyed your article. I'm new to this, so the discussion about how power is measured and the issues involved with power was interesting and helpful.

But the parts I most enjoyed were the background history of the receiver and the insight into product management. I've been looking at the differences between Yamaha HTR and RXV lines recently and your discussion of product management gave me some insight/confirmed some of my thinking. The history bit relly helped add some valuable context to the discussion.

Thanks for taking the time to put it together. Well done.

 

[Leprkon]

Pat;

I think people are more interested in debating the magic of exotic cables

like whether we can use them on the werewo... I really gotta let this go...

 

[aarond]

Patrick,

With your history as a product manager can you explain to me how all the press releases for a YEC receiver claim that it has 910 watts of power , but the unit only has a 500watt power supply. Is this a lie or creative marketing?

aaron

 

[toquemon]

Your article is very interesting. I was specting some measures about true power between today's receivers, something like this:

Yamaha's RX-V1400 is only capable of producing 50 w/ch all channels driven.
Denon's 3805 is only capable of 80 w/ch all channels driven.
bla, bla, bla
1. Now i know that the method commonly used (a sinewave) to measure power in a "all channel driven" test doesn't represent reality at all (music isn't a sinewave).
2, Now i know that ALL manufacturers make some compromises when designing the power suplies.
3. Now i know that almost everyone cheats when measuring power.
4. Now i know that one of the things that is less important is power.
5. Now i know that the legend of my receiver's back panel that states "warning: min 6 Ohms" has nothing to do with the power suply and it's only to comply with UL requirements.
5. Now i know that the engineers have done a very nice job when putting almost everything in a <$1000 box.

Thank you PlHart

 

[gene]

Yamaha's RX-V1400 is only capable of producing 50 w/ch all channels driven.
Denon's 3805 is only capable of 80 w/ch all channels driven.

Perhaps, but its important to note that these receivers will deliver their rated power and then some in at least two channels driven simultaneously. In fact, I found the RX-Z9 delivered alot more power into 4 ohm loads indicating it handled low impedance loads very well without introducing slew rate distortion.

Yamaha RX-Z9 Power Tests

With your history as a product manager can you explain to me how all the press releases for a YEC receiver claim that it has 910 watts of power , but the unit only has a 500watt power supply. Is this a lie or creative marketing?

Yes sometimes that can be creative marketing. Again realize the rear panel rating may NOT be the true limits of the power supply. It is tested per UL under a specific load to achieve that #. You have to look at the VA rating of the transformer and the fuse rating on the voltage rails to really know how much power the receiver is capable of delivering.

 

[Leprkon]

a great job of explaining in terms us non-double e's can understand. the history was very enjoyable as well.

 

[surveyor]

true power money no object

OK, here's a viable solution.
Yamaha RX-V2500 using pre-amp outs ($800.00)
4 each Mark Levinson #33 amps. (4 x 32,000 = $128,000)
Hence not to worry about the all channels driven controversy.
Result, passed all channels driven test.

 

[FLMike]

Ok, here's a question for you

plhart,
First thanks for the article because I am not sure I would really know how to ask you this question without it. I just purchased a Yamaha HTR-5790 receiver. I've got a space issue, so I was thinking of using Magnepan MMG-W's as surrounds in a 5.1 config with Athena AS-F2's as front with a complimentary center channel. These speakers are rated at 5 Ohms.

When I look at the manual on the Yamaha, it offers an 8 Ohm and a 6 ohm option in the setup. So question number one is can you run 5 Ohm speakers if 6 is selected without hurting anything or does sselecting 6 just engage some knd of wattage limiter to prevent overload?

Second, the receiver has several ratings in the specifications section. One is called "Dynamic Power" or IHF. It states the receiver is rated at 185 for 6 Ohm and 240 for 4 Ohm. So I am guessing 5 ohms comes somewhere in between. Are these figures meaningful? Can the receiver handle this type of load and does it matter that it's only running in a 5.1 config (ie is there more power available?)?

Finally, is inserting an external amp to drive those channels an option? They REALLY solve a space issue for me.

Thanks,

Mike

 

[Duffinator]

OK, here's a viable solution.
Yamaha RX-V2500 using pre-amp outs ($800.00)
4 each Mark Levinson #33 amps. (4 x 32,000 = $128,000)
Hence not to worry about the all channels driven controversy.
Result, passed all channels driven test.

Surveyor, I like your thinking. For most of us the mid-fi receivers talked about in the article will provide movie theater like sound stages in our homes and hours of music listening enjoyment.

 

[surveyor]

Surveyor, I like your thinking. For most of us the mid-fi receivers talked about in the article will provide movie theater like sound stages in our homes and hours of music listening enjoyment.

Thanks Duffinator.
Without sounding critical to others, most of todays recievers really blow my mind.
A reciever say 7 x 130 W each channel driven seperately is amazing for around $800.00.
I'm getting up there in age, but what is available in audio equipment now days is truly amazing.
I can't wait to see whats over the horizon.

 

[plhart]

I never cease to be amazed at the kind of questions that come up! Mike, I'm a believer first in trying to get a feeling of envelopment out of surround speakers. And the Maggies, being true dipoles will absolutely fit that bill; if, that is, you're willing to position them at 90 degrees from center, directly to the left and right of your seating position and sticking out perpendicular from the wall. You could hinge them and swing them out only when in use.

The Yammie receiver should have no problem with the 5 ohm Maggies as the load is quite linear. Be aware however that the Maggies sensitivity is low versus the Athena so you'll be asking the amp to deliver at least 4 times more power to the rear. Lastly, from a timbral matching standpoint, the Maggies and the Athena are about as far apart as you can get so take that into consideration. The intent is to have an expansive front soundstage with an enveloping surround environment. So anything your do like severe mismatching of speaker technologies can draw attention to that fact and ruin the illusion.

 

[FLMike]

Too much of a difference?

phart,
Thanks for the quick answer. The hinged idea was exactly what I had in mind. Flat when not in use, toed out when used for surround. Timbre is also a concern, especially since I love music and would like to play through the entire group sometimes. That is why I got matched fronts and center. How big of an issue do you see with the sensitivity disparity between front and back? Can the YPAO EQ functionality compensate for it effectively, or will the Maggies always seem "quiet" and as you said draw too much attention to the differences between the two speaker types?

And back on topic, what is Yamaha doing with the 6 ohm setting vs the 8 ohm? Limiting the draw on the power supply by reducing the load?

Mike

 

[plhart]

"How big of an issue do you see with the sensitivity disparity between front and back? Can the YPAO EQ functionality compensate for it effectively, or will the Maggies always seem "quiet" and as you said draw too much attention to the differences between the two speaker types?"

Assuming you still have enough power to drive the entire system to adequate levels as far as you're concerned ,the sensitivity disparity could become an issue depending on how the amps/heatsinks are laid out inside the receiver.

If for instance you have the front three amp/heatsink channels mounted on the outside of the receiver and the surround amp/heatsinks are tucked more into the middle of the unit there could be a real issue with the heat disparity between the two and adequate ventilation for those middle heat sinks.

An engineer would usually assume the exact opposite, that the front three channels would generate the most heat under load. So you may be really bucking some design assumptions which could led to protection circuits shutting down the whole unit under what would sound like "normal" levels to you.

The auto set-up circuitry which is on the DD chip is completely separate for setting up the levels so if you do this step correctly the Maggies shouldn't really seem "quiet". And the YPAO circuitry will do whatever it does based on five speakers speakers and how it reads those five speakers' interaction with the room. It doesn't know from Adam that the Maggies are panels but it may adjust differently as it reads the comb-filtering type response that a dipole panel will probably emit. That reading, however, depends on the type of spatial averaging (1/3??, 1/6?? octave)the YPAO performs. In short, I can't answer that question. You gotta try it.

Lastly you probably will draw attention to the two speaker types' disparities because the human ear is very sensitive to the sound differences of panels versus direct radiators. Both the frequency and power response of these two types are typically quite opposite. Beamy, and ragged on axis with zippo power response vs. flat on-axis with excellent power response exhibiting flat response but with amplitude decreasing as frequency increases.

"What is Yamaha doing with the 6 ohm setting vs the 8 ohm? Limiting the draw on the power supply by reducing the load?"

Passing UL and other agency approvals more easily. Gene has explained this in other posts if you look around.

Glad you liked the Product Managing Receivers articles. Good questions. It used to be guys like you who would drive us nuts because we would never anticipate of some these kinds of speaker/receiver considerations when we designed. Gotta design for the 99% of consumers to hit performance vs. price points. Too much competition to think otherwise.

 

[FLMike]

Back to the drawing board

Thanks for the detailed answer. Looks like this solution is probably a bad fit for several reasons. As for people like me driving engineers nuts, I work with PBX's and computer systems and I am always AMAZED at at how "creative" customers can be. I'm also always amazed by their unflinching ability to make everyone else responsible for the results of their little "experiments" LOL.

I'll rethink this speaker situation and come up with something that is more in line with intended spec. But I need something small and inconspicuous with good sound.
Mike

 

[plhart]

If you're going for the immersion effect I would guess that a couple of the little ball speakers available from a couple of different manufacturers, mounted back-to-back on Omnimounts might fit the bill. Small round, unobtrusive and pointable for best effect.