# I'm curious, why do most Yamaha receivers hover around 100 wpc?



## mjcmt (Aug 30, 2010)

Looking over the current crop of Yamaha receivers is seems like they are all right around 100 wpc with changes generally in features. The new Advantage line have squeezed out a little more juice w/ a bit lower distortion, but not as good as some of the past models. Other than the Advantage line their amps have greater THD than in the past. Looks like they found a good 100 watt-ish amp and have stuck with it over the years, but they seem noisier.

The new:
RXA3020 150W (8ohms, 0.06% THD) (20Hz-20kHz, 2ch driven)
RXA2020 140W (8ohms, 0.06% THD) (20Hz-20kHz, 2ch driven)

RXV773wa 95W (8ohms, 0.09% THD) (20Hz-20kHz, 2ch driven)
RXV663 90W (8ohms, 0.09% THD) (20Hz-20kHz, 2ch driven)
HTR7065 95W (8ohms, 0.09% THD) (20Hz-20kHz, 2ch driven)

And my older:
RXV659 100W (8ohms, 0.06% THD) (20Hz-20kHz, 2ch driven)
HTR5990 120W (8ohms, 0.04% THD) (20Hz-20kHz, 2ch driven)

Inquiring minds want to know.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Not sure I get the point of your post, asking why Yamaha receivers “hover” at ~100 watts, then showing us a comparison chart with receivers in the 140-150 watt range? :scratch:

Keep in mind that distortion (THD) and noise have nothing to do with each other. Since it’s generally accepted that distortion doesn’t become audible until it hits the 2-3% range, a difference between 0.04 and 0.09 % THD is insignificant.

Regards, 
Wayne


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## mjcmt (Aug 30, 2010)

Wayne A. Pflughaupt said:


> Not sure I get the point of your post, asking why Yamaha receivers “hover” at ~100 watts, then showing us a comparison chart with receivers in the 140-150 watt range?
> a difference between 0.04 and 0.09 % THD is insignificant.




I qualified with "The new Advantage line have squeezed out a little more juice" so as to not get smarty pants to complain about that they put out more, but to no avail.
I'm not sure your correct in your THD statement.


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## 8086 (Aug 4, 2009)

Wayne A. Pflughaupt said:


> Not sure I get the point of your post, asking why Yamaha receivers “hover” at ~100 watts, then showing us a comparison chart with receivers in the 140-150 watt range? :scratch:
> 
> Keep in mind that distortion (THD) and noise have nothing to do with each other. Since it’s generally accepted that distortion doesn’t become audible until it hits the 2-3% range, a difference between 0.04 and 0.09 % THD is insignificant.
> 
> ...


I agree, I don't quite think I get the question.

I'm sure Amplifier Topology and price point have something to do with the WPC in a given product line. If they were class D amps, you would get a lot more WPC per dollar than say a Class A/B amp, mostly due to efficiency. Also, note that you can only draw so much power out of an outlet. The more channels you have to drive, the more power you draw or the smaller your WPC will be.


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## tonyvdb (Sep 5, 2007)

To be honest the one single number to look at is the over all weight of the receiver. If its rated at 130 watts per channel and it only weighs 30lbs the power supply is way to small to drive the amps thus giving distortion when driving all channels. Most receivers loose about 30% of their rated output due to this.


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## 8086 (Aug 4, 2009)

Wayne A. Pflughaupt said:


> Not sure I get the point of your post, asking why Yamaha receivers “hover” at ~100 watts, then showing us a comparison chart with receivers in the 140-150 watt range? :scratch:
> 
> Keep in mind that distortion (THD) and noise have nothing to do with each other. Since it’s generally accepted that distortion doesn’t become audible until it hits the 2-3% range, a difference between 0.04 and 0.09 % THD is insignificant.
> 
> ...





tonyvdb said:


> To be honest the one single number to look at is the over all weight of the receiver. If its rated at 130 watts per channel and it only weighs 30lbs the power supply is way to small to drive the amps thus giving distortion when driving all channels. Most receivers loose about 30% of their rated output due to this.


:clap: :T:

Numbers only tell a 20% of the story and are most often only useful for comparing things in the same product family line. Like one Paradigm Monitor model vs another Paradigm Monitor. The numbers may appear the same, but the sound is totally different. People often do this with amplifiers and come up short in the final delivery of sound.


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## chashint (Jan 12, 2011)

Its not just Yamaha, most AVRs are around 100 watts per channel.
I think 100 watts is a psychological number, I know I want 100 watts whether I need them or not.
As was mentioned before pulling 700 watts max out of the wall still leaves plenty for TVs and other electronics on a standard breaker. 
In the real world there is not much difference between 100 watts and 200 watts when it comes to SPL out of the speakers, for that extra 100 watts best case is a 3dB increase.
In the real world most people only use a few watts per channel anyway so 100 watts is usually overkill to begin with.
It costs more to manufacture a 200 watt per channel amp for little if any real benefit, that money is being used for other features which may or may not be of benefit, but if not present kill the product.


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## Tonto (Jun 30, 2007)

Ditto for marketing, my Yammy is 75 WPC & I rarly turn the knob past 1/4.


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## tonyvdb (Sep 5, 2007)

chashint said:


> Its not just Yamaha, most AVRs are around 100 watts per channel.
> I think 100 watts is a psychological number, I know I want 100 watts whether I need them or not.
> As was mentioned before pulling 700 watts max out of the wall still leaves plenty for TVs and other electronics on a standard breaker.


The wattage draw of a receiver has little to do with the actuall power output of an amp. It depends much more on the efficiency of the design. In the real world most receivers are actually much less than 100wats per channel. Its not until you get into receivers that weigh over 45lbs that you can even dream of getting more out of them.


> In the real world there is not much difference between 100 watts and 200 watts when it comes to SPL out of the speakers, for that extra 100 watts best case is a 3dB increase.
> In the real world most people only use a few watts per channel anyway so 100 watts is usually overkill to begin with.


Huh? 3db more for 100wats is not at all accurate. It all depends on the speakers your driving as to how much more volume you will get it also is dependent on if they are 8 or 4Ohm, inefficient speakers will require much more power. 


> It costs more to manufacture a 200 watt per channel amp for little if any real benefit, that money is being used for other features which may or may not be of benefit, but if not present kill the product.


Again not correct. Cost has nothing to do with it. Its all about supply and demand nothing more. Boutique brands can also be costly simply due to the name.


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## chashint (Jan 12, 2011)

Tony, I take great exception to your response.
In all cases where you quoted me and rebuked my statements, I am correct and you are in error.
I will leave it at that.
As an example....
http://www.musiccenters.com/vol.html 
This is as plain language as I could find.
The rest is not worth any effort on my part to educate you.


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## jevans64 (Dec 24, 2012)

tonyvdb said:


> To be honest the one single number to look at is the over all weight of the receiver. If its rated at 130 watts per channel and it only weighs 30lbs the power supply is way to small to drive the amps thus giving distortion when driving all channels. Most receivers loose about 30% of their rated output due to this.


That is going to also depend on what type transformer is being used. Most manufacturers have switched back to the E-I type transformers because they are cheaper to make. They are generally half as efficient as toroidal transformers and can weigh up to twice as much. That may be why the OP's THD numbers are slightly higher in the new Yamaha vs. the old Yamaha. E-I's produce more noise and hum than toroidal. A receiver with an E-I transformer that kicks out 100w x 7 will probably need a massive 1.8 kVA transformer to deliver the goods while the same receiver with a toroidal only needs maybe a 1.1 kVA transformer. That right there would slice off about 14 pounds from the receiver's total weight.

As to the OP's original question. 100 watts/channel is generally all that is needed for the average multi-channel setup. Most mid to low receivers are aimed at those who just want a simple setup for their living room or family room.

Something I wish the receiver manufacturers would provide is the type and output of the transformers in their receivers. I'm tired of all this marketing mumbo-jumbo when providing rated output. Only a handful of amplifier manufacturers advertise their transformer specs. My Emotiva XPR-5 is advertised as a Class-H with a 3.3 kVA toroidal transformer, so I knew EXACTLY what I was getting for my money... a guaranteed 2000 watt output.


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## tonyvdb (Sep 5, 2007)

I agree, toroidal transformers are the best. Ive got two Samson amps that have them, the round shape of the PS is a dead giveaway. I never turn them off as they draw so little power when not in use it does not even show up on an amp meter. Where as my Onkyo left on with nothing playing draws 1.2 amps. An it weighs 54lbs! 
I have not seen a receiver that uses one since the Onkyo 905 and 906


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## 8086 (Aug 4, 2009)

tonyvdb said:


> The wattage draw of a receiver has little to do with the actuall power output of an amp. It depends much more on the efficiency of the design. In the real world most receivers are actually much less than 100wats per channel. Its not until you get into receivers that weigh over 45lbs that you can even dream of getting more out of them.
> 
> Again not correct. Cost has nothing to do with it. Its all about supply and demand nothing more. Boutique brands can also be costly simply due to the name.



When it comes to AV receivers, they do make 150-180+ watt 8-10 channel units, but they do cost a lot and often as much as separate components from a boutique vendor.

Some Boutique brands Like McIntosh, Antehm, or Krell, B&O (ICE Amps), or BAT (Balanced Audio Technologies) cost more because of higher quality as well as paying for the costs of R&D on that product or future products. But there are a few brands here and there that just charge more for the name (eh-hem, Lexicon you repeat offender). 

Some brands (possibly Emotiva, sorry!) may not do any or little R&D and are able to sell you a product at lower cost. I see this as a double edged sword, obviously- one side I get a good quality cheap amp, on the other side- it may (or may not) cause a bottom up collapse in innovation due to the low $$ end cutting out the high $$ end who may be the ones putting up capital for newer and improved designs. While the bottom end may be feeding on expired patents of tweaked designs from years past.




> Huh? 3db more for 100wats is not at all accurate. It all depends on the speakers your driving as to how much more volume you will get it also is dependent on if they are 8 or 4Ohm, inefficient speakers will require much more power.


I think he may have meant 3db SIGNAL gain as measured from the speaker terminals of the amplifier and not the sound output from the speaker. FTC Amplifier Power measurements are taken with an 8ohm load and are the only way you can claim an amp has 100 wpc.


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## tonyvdb (Sep 5, 2007)

chashint said:


> Tony, I take great exception to your response.
> In all cases where you quoted me and rebuked my statements, I am correct and you are in error.
> I will leave it at that.
> As an example....
> ...


You have not really tested this have you?
If that was the case then I would have a faulty SPL meter and my ears are telling me very different.
I have two amps one is 150watts per ch the other is 300watts per ch both made by the same manufacturer and same line.
I ran my EV sentry 500s off the Samson servo 300 for a few months and found it would peak at about 85db on many movies and music. I now have the Servo 600 hooked up and Im not even close to peak and I can get up to 100db and Its not even near its max output. Thats a lot more than 3db


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## NBPk402 (Feb 21, 2012)

tonyvdb said:


> The wattage draw of a receiver has little to do with the actuall power output of an amp. It depends much more on the efficiency of the design. In the real world most receivers are actually much less than 100wats per channel. Its not until you get into receivers that weigh over 45lbs that you can even dream of getting more out of them.
> 
> Huh? 3db more for 100wats is not at all accurate. It all depends on the speakers your driving as to how much more volume you will get it also is dependent on if they are 8 or 4Ohm, inefficient speakers will require much more power.


The dif between a 100w amp and a 200w amp is 3dbw... In order to get 3db louder you must double the power so if we are talking 100w to start with we would have to go to 200w to have a 3db dif whereas if we were talking 200w we would have to go to 400w to hear a 3db dif.


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## 8086 (Aug 4, 2009)

jevans64 said:


> That is going to also depend on what type transformer is being used. Most manufacturers have switched back to the E-I type transformers because they are cheaper to make. They are generally half as efficient as toroidal transformers and can weigh up to twice as much. That may be why the OP's THD numbers are slightly higher in the new Yamaha vs. the old Yamaha. E-I's produce more noise and hum than toroidal. A receiver with an E-I transformer that kicks out 100w x 7 will probably need a massive 1.8 kVA transformer to deliver the goods while the same receiver with a toroidal only needs maybe a 1.1 kVA transformer. That right there would slice off about 14 pounds from the receiver's total weight.
> 
> As to the OP's original question. 100 watts/channel is generally all that is needed for the average multi-channel setup. Most mid to low receivers are aimed at those who just want a simple setup for their living room or family room.
> 
> Something I wish the receiver manufacturers would provide is the type and output of the transformers in their receivers. I'm tired of all this marketing mumbo-jumbo when providing rated output. Only a handful of amplifier manufacturers advertise their transformer specs. My Emotiva XPR-5 is advertised as a Class-H with a 3.3 kVA toroidal transformer, so I knew EXACTLY what I was getting for my money... a guaranteed 2000 watt output.



Those who market an amplifier with a toroidal transformer gain more market sway with consumers. More power to them and the rest will follow!


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## tonyvdb (Sep 5, 2007)

ellisr63 said:


> The dif between a 100w amp and a 200w amp is 3dbw... In order to get 3db louder you must double the power so if we are talking 100w to start with we would have to go to 200w to have a 3db dif whereas if we were talking 200w we would have to go to 400w to hear a 3db dif.


My findings below prove this to be inaccurate.

"I have two amps one is 150watts per ch the other is 300watts per ch both made by the same manufacturer and same line.
I ran my EV sentry 500s off the Samson servo 300 for a few months and found it would peak at about 85db on many movies and music. I now have the Servo 600 hooked up and Im not even close to peak and I can get up to 100db and Its not even near its max output. Thats a lot more than 3db"


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## NBPk402 (Feb 21, 2012)

tonyvdb said:


> My findings below prove this to be inaccurate.
> 
> "I have two amps one is 150watts per ch the other is 300watts per ch both made by the same manufacturer and same line.
> I ran my EV sentry 500s off the Samson servo 300 for a few months and found it would peak at about 85db on many movies and music. I now have the Servo 600 hooked up and Im not even close to peak and I can get up to 100db and Its not even near its max output. Thats a lot more than 3db"


Maybe one of the amps must have more dynamic power than the other? What I stated is a basic math formula for logarithmic/ exponential scale. I am at a loss as to how you got that kind of dif other than dynamic power being dif.


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## tonyvdb (Sep 5, 2007)

They are identical amps other than the wattage output, they have 9 segment LED power output indicators for each channel and they dont lie. Its not the first time Ive run into this. I dont usually put to much faith in numbers as real world tests often prove them wrong.


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## NBPk402 (Feb 21, 2012)

tonyvdb said:


> They are identical amps other than the wattage output, they have 9 segment LED power output indicators for each channel and they dont lie. Its not the first time Ive run into this. I dont usually put to much faith in numbers as real world tests often prove them wrong.


Have you contacted the Manufacturer? Maybe the smaller one is defective and should be putting out more power.


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## tonyvdb (Sep 5, 2007)

Nothing sounded off, its in my livingroom setup now and is working fine.


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## 8086 (Aug 4, 2009)

tonyvdb said:


> They are identical amps other than the wattage output, they have 9 segment LED power output indicators for each channel and they dont lie. Its not the first time Ive run into this. I dont usually put to much faith in numbers as real world tests often prove them wrong.



Amplifier power output LEDs are not a very accurate means of judging output.


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## tonyvdb (Sep 5, 2007)

I know but for the amps capable power output its the only way to tell if its running hard or not. I have a good SPL meter that Ive checked it with. There is a very big level difference between the two amps.


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## 8086 (Aug 4, 2009)

tonyvdb said:


> I know but for the amps capable power output its the only way to tell if its running hard or not. I have a good SPL meter that Ive checked it with. There is a very big level difference between the two amps.


3db of electrical gain from 100 watts cannot be measured with an SPL meter.


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## tonyvdb (Sep 5, 2007)

I know but clearly we are not getting only 3db of gain translated to actual volume (SPL) increase.


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## chashint (Jan 12, 2011)

tonyvdb said:


> They are identical amps other than the wattage output, they have 9 segment LED power output indicators for each channel and they dont lie. Its not the first time Ive run into this. I dont usually put to much faith in numbers as real world tests often prove them wrong.


Actually a real world test where you understand the environment (which could include room gain) will prove the math works every single time.
My background is electrical engineering, not acoustical engineering, but the language is similar and except for the constants the math is pretty close to being the same too.
I make no claim of being an expert on the acoustical side, but everything I have read supports a speakers output SPL increasing 3dB with a input power increase of x2.
There are multiple references published from a variety of reliable sources revealed with a simple Google of spl vs input power, I welcome everyone interested in this discussion to try it for themselves.
These are pulled from the first 5 hits but there are many more, I have found no material that refutes this.
http://www.puiaudio.com/pdf/speaker_power_distance.pdf 
http://www.sabre-international.com/a-simple-guide-to-loudspeaker-technology.html 
When someone is convinced they are correct and engineers are wrong, I really have no way to communicate with that individual.
All I can say is that I try not to shoot from the hip and make declarations that are fueled by emotion and unsubstantiated opinion.
The only reason I continue to participate in this thread is to provide links to information that may help others that are interested in real world factual information.


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## 8086 (Aug 4, 2009)

chashint said:


> Actually a real world test where you understand the environment (which could include room gain) will prove the math works every single time.
> My background is electrical engineering, not acoustical engineering, but the language is similar and except for the constants the math is pretty close to being the same too.
> I make no claim of being an expert on the acoustical side, but everything I have read supports a speakers output SPL increasing 3dB with a input power increase of x2.
> There are multiple references published from a variety of reliable sources revealed with a simple Google of spl vs input power, I welcome everyone interested in this discussion to try it for themselves.
> ...


Someone on this forum isnt using a scientific method nor is he/she using proper or good equipment to take measurements. Keeping all electrical situations under a control and using speakers as a variable, actual sound DB output will vary based on the sensitivity of the speakers sensitivity rating (watt decibel-meter w db/m).


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## Wayne A. Pflughaupt (Apr 13, 2006)

I think there would just be too many unpredictable variables in gauging the theory from the SPL generated by the maximum output of two different amps. Even if they’re from the same model line, the manufacturer could very well – and probably does - “put more into” the upper-tier model. Better-quality or larger caps, for instance. There could have been issues with the lower-priced transformers sourced by the manufacturer’s supplier for the lesser model – who knows what all else could be added to the mix? And of course, manufacturer power ratings can often be “tweaked.”

An easy (although technically “unscientific”) test is actually pretty simple. Just play a signal source (preferably a test signal like pink noise) from one of your speakers – say, the left one. Take a SPL reading, then add the right speaker. You have now factually doubled the power output, and you have identical speakers. Take a second SPL reading and you’ll probably find the difference between the two is ~3 dB.

Regards, 
Wayne


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## 8086 (Aug 4, 2009)

mjcmt said:


> Looking over the current crop of Yamaha receivers is seems like they are all right around 100 wpc with changes generally in features. The new Advantage line have squeezed out a little more juice w/ a bit lower distortion, but not as good as some of the past models. Other than the Advantage line their amps have greater THD than in the past. Looks like they found a good 100 watt-ish amp and have stuck with it over the years, but they seem noisier.
> 
> The new:
> RXA3020 150W (8ohms, 0.06% THD) (20Hz-20kHz, 2ch driven)
> ...


Im sure the current state of the economy and a motive to keep things affordable may have something to do s with the cuts. Kind of like GM in the 70s bringing out smaller cheaper cars as a response to economic conditions.


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## tonyvdb (Sep 5, 2007)

8086 said:


> Im sure the current state of the economy and a motive to keep things affordable may have something to do s with the cuts.


Oh for sure! even keeping the weight down in a receiver by using smaller power supplies will save huge amounts of money as shipping is a big part of the cost.


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## erwinbel (Mar 23, 2010)

As far as I can tell, if Yamaha wants to stick to plain class AB, there's only so much of transformer size that can be inside the box before it gets to hot. 

My Yamaha RX-V2700 is now almost six years old. I bought a UMC-1 only to get the upgrade certificate (-40%) towards a Reference pre-pro that will hopefully be avalable once our HT is ready... Planned to sell the UMC-1.

But I decided to replace the Yammie with the UMC-1 in our living room. Yamaha has been flawless and has features that the new Emotiva's doesn't have even today. But I don't use things like internet radio anyway. 

The XPR-5 will temporarily be used as poweramp.


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## bmdtech (Dec 17, 2011)

The reason most manufacturers stick ~ 100 watts per chan is basic math. As has been discussed already, every time you double the power you add 3db. Many speakers are rated as such. X db at 1 watt at 1 Meter.

So, lets pick a normal speaker rating say. 88 db efficient at 1 watt at 1 Meter. Now, double the power.

2 W = 91 db
4 W = 94 db
8 W = 97 db
16 W = 100 db
32 W = 103 db
64 W = 106 db
128 W = 109 db

Now this scale shows you the db rating of a speaker running at 128 W. If the speaker is a well built unit with drivers able to handle the full power of a 128 Watt amp then we are talking quite loud. For most average quality speakers they are going to start pooping out at around 50 watts, either because they are heating up the coil to much, compressing due to not rigid enough cone or not enough xmax. All sorts of different reasons really.

The most cost effective and bang for your buck target for most receiver users is right around 100 watts per channel. As also was stated in this post, now you see why most of the time the receiver is running well below its power threshold. It takes just a few watts to start being loud, it takes a tremendous amount to gain much above and beyond the 128 watt ceiling to gain much volume.


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