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100 wpc vs 130 wpc : Is there really any noticeable difference?

18K views 40 replies 20 participants last post by  walbert 
#1 ·
Let's say we're talking about electronics in the same tier of quality. Just for the sake of providing a specific example, the Yamaha RX-A1000 vs the Yamaha RX-A3000 (or comparable Denon, Onkyo, Pioneer, etc.)


Does 30 watts really make any audible difference? If it takes double the wattage to gain only 3db, what's the point? (besides the different features - I'm talking stricly about wattage & sound)
 
#27 ·

Quote:
Originally Posted by bfreedma /forum/post/20719605


^^^^


One of the least useful numbers in all of AV is the ACD (All Channels Driven) numbers for an AVR. This does not represent any kind of real world application, as unless you enjoy deafening yourself by running test tones a extraordinary volume through all 5 channels simultaneously...

I understand the thinking behind this. And it's not wrong.


But, an all channels driven test is not pointless IMO. Here's my thinking. If you take some $200 Sony AVR, it might be rated at 100 watts / channel. Probably at 1kz, and 1% THD.


You might look at a better receiver, which has 110 watts / channel, and conclude they have similar performance. Maybe it's rated at a better THD, but still, you may think, well, why not get the Sony, seems ok.


Then you put both models on the test bench, and subject them to an all channels driven test. The Sony drops to 25 watts / channel or worse. The other receiver drops to 50 watts. I think you just learned something. At least I did. Not picking on Sony, this sort of thing is true when testing various budget receivers vs better mid range models...


In some ways, price is a fair indication with the mass market brands. It would seem to be a tough market, and they are not going to be able to juggle prices much until the price tag gets above $1000. So a $600 receiver will almost certainly have better performance than a $300 receiver. Probably not twice though, but the feature upgrade on the midrange model may be compelling as well.
 
#28 ·

Quote:
Originally Posted by MichaelJHuman /forum/post/20722851


I understand the thinking behind this. And it's not wrong.


But, an all channels driven test is not pointless IMO. Here's my thinking. If you take some $200 Sony AVR, it might be rated at 100 watts / channel. Probably at 1kz, and 1% THD.


You might look at a better receiver, which has 110 watts / channel, and conclude they have similar performance. Maybe it's rated at a better THD, but still, you may think, well, why not get the Sony, seems ok.


Then you put both models on the test bench, and subject them to an all channels driven test. The Sony drops to 25 watts / channel or worse. The other receiver drops to 50 watts. I think you just learned something. At least I did. Not picking on Sony, this sort of thing is true when testing various budget receivers vs better mid range models...


In some ways, price is a fair indication with the mass market brands. It would seem to be a tough market, and they are not going to be able to juggle prices much until the price tag gets above $1000. So a $600 receiver will almost certainly have better performance than a $300 receiver. Probably not twice though, but the feature upgrade on the midrange model may be compelling as well.

No news there - there are certainly quality differences in amps and how they handle load. That said, the testing process and associating results with amp requirements itself is, IMO, fatally flawed, as it is based on a metric that doesn't represent real world operations. There simply isn't a scenario where actual content will drive all channels, long term, at maximum output. Now if the manufacturers would give us a short duration version of that test, we would really have a more valuable set of data.


Add to that the reality that very few users will ever ask the amps to put out more than a few watts, and I just don't consider power to be a compelling differentiator in AVR's. As you state, the feature set, particularly EQ options, is, to me, the area to focus on when selecting an AVR.


As mentioned before, if you have difficult speakers to drive, listen @ reference, or have an exceptionally large space, then power does become a factor, but for most, not so much. I certainly wouldn't give up a preferred EQ solution to get a few more real world wpc.


I agree with you though in the case where a very competent amp section is compared to a very low end model, but that wasn't, IMHO, what the OP was comparing.


Anyhoo, it's an interesting discussion and everyone can decide where they want to spend. Sometimes, it's just nice to know you have more power, whether you really need it or not. For example, I have a 200 wpc channel amp hanging off a Denon 4311 driving 91db sensitive speakers in a mid size room. Can I justify it intellectually? Not a chance, but it's fun to try new gear and while it's probably more placebo than real, I think at reference, my system sounds better. At levels below reference, I know there is no impact.


Cheers,


Ben
 
#29 ·

Quote:
Originally Posted by niceguymr /forum/post/20721800


Let me pose another scenario. I'm currently running a 100wpc AVR and find that I'm able to reach the limit of it's output when watching movies in Dolby Surround. It's something I didn't know was possible - that I could have the gain turned up as loud as possible, with the sound coming through crystal clear, yet having reached a 'ceiling' of volume. While this 'ceiling' or 'limit' of volume while watching a movie MIGHT be considered adequate to most, I would certainly not mind just a hint more volume - just a tad. Would the extra 30 wpc make a difference then? (again, assuming all other equipment same)

One very noticeable difference with a bigger amp is that comfortable listening levels increase. Less fatigue, audible distortion and more clean - musical bass (assuming large full-range speakers).


Listening fatigue may be the most reliable indicator of how well your setup is performing. If it hurts and tires you quickly, either the speakers are not up to the task or the amp is clipping or both.


There's no real way to know when an amp will start clipping, it depends on the source material. But with multichannel high-res music, odds are good it will be at moderate levels.


If you're a power hog and like to crank it up, consider moving away from AVRs to real amps to drive your speakers. AVRs still make good pre/pros if they have line-outs. A modest $500 AVR with a dedicated amp can even cost less than a $2000 AVR with higher power. Power in an AVR is the carrot to get you to buy all the expensive processing that you don't really need.


Yamaha A800 = $500

Emotiva XPA-5 = $900


Yamaha A2000 = $1400

Yamaha A3000 = $1800


If you want more than 5 channels, the smaller AVR can still drive the extra 2 just fine.
 
#30 ·

Quote:
Originally Posted by rdgrimes /forum/post/20723089


One very noticeable difference with a bigger amp is that comfortable listening levels increase. Less fatigue, audible distortion and more clean - musical bass (assuming large full-range speakers).


Listening fatigue may be the most reliable indicator of how well your setup is performing. If it hurts and tires you quickly, either the speakers are not up to the task or the amp is clipping or both.


There's no real way to know when an amp will start clipping, it depends on the source material. But with multichannel high-res music, odds are good it will be at moderate levels.


If you're a power hog and like to crank it up, consider moving away from AVRs to real amps to drive your speakers. AVRs still make good pre/pros if they have line-outs. A modest $500 AVR with a dedicated amp can even cost less than a $2000 AVR with higher power. Power in an AVR is the carrot to get you to buy all the expensive processing that you don't really need.


Yamaha A800 = $500

Emotiva XPA-5 = $900


Yamaha A2000 = $1400

Yamaha A3000 = $1800


If you want more than 5 channels, the smaller AVR can still drive the extra 2 just fine.

I was going to this with my Yamaha RX-V1900 HD AVR (retailed $1,300.00) 130X7 and purchase a 200X5

amp. I got lucky as Pop's old Cornwalls and my Heresey II sound great in very small den with just the AVR.
 
#31 ·

Quote:
Originally Posted by bfreedma /forum/post/20722970



Add to that the reality that very few users will ever ask the amps to put out more than a few watts...


Ben

That's likely true for average power, but peaks will require substantially more power. Consider the the usual quoted figure for movies is a 20 dB dynamic range. With that figure, you need 100 times the power for peaks than you do for average level.
 
#32 ·
The weight is on "substantially", which is not the relatively meager difference between 100 and 130 Watts, however they have been measured by the manufacturer (or its marketing department
)


In a HT system, which includes at least one active sub, this is not really that relevant anymore, because the power-hungry bass section (
 
#33 ·

Quote:
Originally Posted by MichaelJHuman /forum/post/20726179


That's likely true for average power, but peaks will require substantially more power. Consider the the usual quoted figure for movies is a 20 dB dynamic range. With that figure, you need 100 times the power for peaks than you do for average level.

The challenge of headroom peak power depends upon the length of the peak demand and amount of regulation in the power supply..

The shorter the peak the easier for the amp/power supply to respond, consider like 200 nano-seconds or 200 milli-seconds...



Just my $0.02..
 
#34 ·

Quote:
Originally Posted by niceguymr /forum/post/20719397


Let's say we're talking about electronics in the same tier of quality. Just for the sake of providing a specific example, the Yamaha RX-A1000 vs the Yamaha RX-A3000 (or comparable Denon, Onkyo, Pioneer, etc.)


Does 30 watts really make any audible difference? If it takes double the wattage to gain only 3db, what's the point? (besides the different features - I'm talking stricly about wattage & sound)

A quality amp that can actually deliver the wattage/power its rated for (most are overrated), you will be deaf at about as low as 40-50watts (depending on speaker), so at 100-130 you won't hear anything.


So to answer your question, nope it won't make a difference.


However if you take about amps that purely lie about thier wattage rating...which most inexpensive-midrange amps (receivers) actually do, then yes 30watts might make a difference, because their increase of 30watts will in reality be more like 1-2watts (unless you have a good quality brand).


But then again it depends on the speakers, more efficient ones will require less power.
 
#35 ·
As has been said a dozen or so times - no it won't make a difference in terms of audibility; we're talking about a very small jump. What I find somewhat comical is that the debate over "well halve the power - thats reality" goes on after it's been stated that even double power doesn't make a difference (3 dB and all).


I've seen a number of reviews that substantiate receivers in the $1000+ range delivering their rated output (or close enough as to not be worth arguing over), and I've seen similar reviews that show $300-$400 products falling off a cliff.


Some examples:
http://www.hometheater.com/content/s...-labs-measures (what we absolutely don't want to see - there's so little power available that headroom does actually go out the window in this situation; 1-3W input will probably get you the 80-90 dB output, but what about the 10 or 100 fold power increase for dynamic peaks?)
http://www.hometheater.com/content/s...-labs-measures (what we absolutely do want to see)
http://www.hometheater.com/content/i...-labs-measures (what we absolutely do want to see)
http://www.hometheater.com/content/a...-labs-measures (for the price, what we absolutely do not want to see)
http://www.hometheater.com/content/p...-labs-measures ("average" - this is roughly what people are getting at in terms of midrange equipment)
http://www.hometheater.com/content/s...-labs-measures (actually outperforms more expensive equipment in terms of ACD - cost/brand name can't always be used as an indicator of performance)
http://www.hometheater.com/content/y...-labs-measures (one of the actual units in question - hitting fairly close to its targets)


Now, Yamaha specs that thing at 100wpc, and we're talking about 30W of difference, so what's "lost" between the 100wpc claim and the 70wpc output? About 1 dB.


As to why this doesn't matter, at least not as much as we'd think it does, let's continue. First off - in order to perceive a "doubling" or "halving" of loudness, the signal's intensity has to increase or decrease by 10 dB - not 1 or 2 or 3 dB. Secondly, all-channels-driven is a maximum output scenario, music and movies won't ever re-create this (if they did, there'd be none of this headroom that's being argued over) - so if we read a bit further into that Yamaha's numbers, it blows right past 100W into a single channel (170.5W). If we figure that a single channel, or perhaps a pair of channels, will actually be demanding peak outputs at any given point - well, I can't say this absolutely, but I'm guessing you'll get that full 100W (assuming the signal is "hot" enough to demand that).


Not all receivers lie about their numbers, and even if the device doesn't reach its all-channels spec, it will probably deliver that power into a single channel (even the godawful Sherwood gets pretty close at around 75W, close enough that I doubt you could pick it apart from most of the other units listed up there unless you were doing 7-channels ACD against one of the Sony units, for example). This is probably "good enough" for most situations. That said, I'd probably take something like the DN1000 over the VSX1120, or the Integra over the Anthem.


Finally, using the nameplate rating on the receiver is potentially an inaccurate way to measure its power supply capabilities - often this is an average consumption value, or some invented number. Remembering that the average user will probably never need more than a few watts per channel, the AVR itself is unlikely to consume much more than what is needed by the internal DSP devices. This means that even the fanciest, highest end units can get away with 300-400W consumption values, even if absolute maximum input approaches something like 1000W. If you're curious about how much power is going into your receiver, get a wattmeter and test it out - I'm sure at normal volume levels it probably doesn't budge much over what the computer parts need to run, but if you really crank it will probably draw quite a bit of power from the wall (just like any other electronic device - it only consumes what it needs to operate plus loss).


Let's use the Integra from the above links as an example - on the back of the unit it states 7.5A (here's a nice huge picture: http://www.gspr.com/integra/images/dtr_502_rear_300.jpg ), which is 900W from 120VAC. In seven-channel output mode it posts 127.7W at 1% THD, which is 893.9W. If that nameplate rating were true, the Integra would be 99.3% efficient; not even the fanciest Class D amplifiers in the world on their absolute best day could approach that. Reality is, that unit is probably drawing something in the realm of 1500-1600W or better to accomplish that output. We can look at another unit that performed fairly well, the Sony DN1000, which has a nameplate rating of 250W. That unit provided 64.9W at 1% THD, which is 454.3 watts - if the nameplate rating were true the Sony would actually be generating free energy, and have an efficiency of 181% (wouldn't that be nice!). This also assumes the DSPs and other components in these devices draw absolutely no power. However, remember that neither of these units will ever see this scenario aside from a testing situation, they're likely to see 1-5W per channel continuous average, and peaks of 50-100W on a single channel periodically (if ever, we are assuming fairly high outputs are desired) - add that consumption plus loss due to inefficiency to the power drawn by the DSP components, and you can easily fit into the nameplate ratings.


Some further reading about the perception of loudness; amplifier output, sensitivity, and power; and SPLs (and, much to Michael's dismay, because it was hinted at, damping factor):
http://trace.wisc.edu/docs/2004-About-dB/
http://audiokarma.org/forums/showthread.php?t=58829
http://myhometheater.homestead.com/splcalculator.html (you can figure out theoretical output based on speaker efficiency and amplifier power with this toy)
http://www.physics.mcgill.ca/~guymoo.../lecture11.pdf
http://www.butleraudio.com/damping1.php (this is essentially identical to the Roger Rusell website, but presented as text instead of a pdf)


As an absolute addendum (and I think the nails are pretty well in at this point) - the "power freed up by the subwoofer" argument is another curiosity. If we remember that the equal power frequency sits at something between 250 and 350hz (in other words, half of the amplifier's power is needed above and half below this frequency), that would mean if a subwoofer's crossover point were somewhere in there (let's say 300hz because it's comically high and right in the middle), it would remove "half" of the power demand from the other speaker channels/amplifier (this assumes an absolute brick-wall of a crossover, iirc THX says 12 dB/Octave is standard - that isn't exactly a brick wall, but it isn't exactly a rolling hill - you can do the maths and figure out the numbers more exactly though). That "half" would represent 3 dB of additional headroom (so if you went from a hypothetical 30W/ch to 60W/ch), which takes us back to "what's audible?" (10 dB) - see the problem? If we go further into the power distribution across frequencies "thing", the point where you'd see 10-fold reductions in amplifier demands is somewhere around 5khz - an entirely reasonable crossover point for...a midrange driver. Now, we are talking about averages and generalizations here - if we take other factors (like acoustics) into account, low frequencies should be more intense in order to be as loud (and low frequency peaks can demand large amounts of power as a result of that and other factors (driver efficiency being a factor too - your average subwoofer driver isn't going to be as efficient as your fancy horn tweeter)). Also remember that content isn't a test wave (everything is lower than full-scale). Ultimately though, even if the subwoofer could somehow remove 50% of the power demand from the amplifier (which it generally will not/can not), we're still back to 3 dB of additional power ("60W from 30W") - not 10 (300W) or 20 (3000W) dB. I'm not arguing against subwoofers, but am arguing that adding a subwoofer to something like the godawful Sherwood will not help it out in terms of somehow making it able to deliver enough power to bring it to the level of the Integra, Yamaha, or Sony ES boxes.


See here for more:
http://sound.westhost.com/bi-amp.htm#power_dist
 
#36 ·
There are some very good links about Perception Of Loudness and other links are good information. But I do NOT believe what Home Theater Shacks Lab Tests.........
The guy that runs that site has a ego larger then Donald Trump.
Do NOT believe what they print about "Their" tests on a AVR. A local High End shop has done some testing too and their specs on some of the same AVR were way different.Yes all of the AVR factory specs are off but HT Shack seems to favor some brands more then others. It's all about the $$$$ on their specs. Show us a different Lab tests on any Yamaha AVR and compair it to HT Shacks lab tests at 5 channels driven. I have owned alot of different brands in 40 years, don't get caught up on one forums Lab Tests as being the allmighty truth.Other then that you posted some Good information.
 
#37 ·
Quote:
Originally Posted by schan1269
I have a slightly different view...


I don't take the absolute power rating...I halve it, in this case...


50 vs 65(which is the real amount you will consider once you take it to all 5 channels)


Will you really notice a difference between 50 and 65? Not really. But the extra 15 comes in handy when you explore dynamic range...


take a 90db speaker(Polk Monitor 70)


1 watt is 90db

2 is 93db

4 is 96db

8 is 99db

16 is 102db

32 is 105db

64 is 108db


If you are listening to reference volume of your receiver (which attempts to mimic 85db with an extra 20db of headroom)...the extra 15 watts can help clear you without straining the receiver. I never like going beyond "half the power you have". So, in my belief where you are running into the possibility of hitting 32 watts...that is easier to accomplish when you have 65 at your disposal...than 50.


I have always recommended people buy an amp to deliver 1/4, but never more than 1/3 of its rating. If you need 32 watts...buy a minimum of 96, but the entire system will be more comfortable on 128. My rounding "back up" takes into account what you will regain by switching from 5 channel back to 2. I am not suggesting you need(what would be...) an equivalent 200wpc amp to play 32 watts.
Keep in mind that you may need to subtract 3db (depends on room treatments) for every doubling of distance starting at 1 meter. Also power compression can eat several db's. So with a listening distance of 13' you could loose as much as 18db (6db for distance and 12db for power compression) if listening at high levels.


As to the OPers question. It takes a doubling of power to gain 3db, so increasing from 100 to 130 watts will not make any difference that you could tell.
 
#38 ·
Quote:
Originally Posted by mjg100
As to the OPers question. It takes a doubling of power to gain 3db, so increasing from 100 to 130 watts will not make any difference that you could tell.
This statement, which gets repeated over and over again, always bugs me because you're looking at it backwards. The better way to look at it is this:


An increase of 3db in volume requires 2x the power. When you approach reference levels this is a significant factor but for most listening not so much. What it does mean is that with any amp, there's a point where increasing levels by only a couple db can mean significant clipping.
 
#39 ·

Quote:
Originally Posted by Louis Bartay /forum/post/20730847


There are some very good links about Perception Of Loudness and other links are good information. But I do NOT believe what Home Theater Shacks Lab Tests.........
The guy that runs that site has a ego larger then Donald Trump.
Do NOT believe what they print about "Their" tests on a AVR. A local High End shop has done some testing too and their specs on some of the same AVR were way different.Yes all of the AVR factory specs are off but HT Shack seems to favor some brands more then others. It's all about the $$$$ on their specs. Show us a different Lab tests on any Yamaha AVR and compair it to HT Shacks lab tests at 5 channels driven. I have owned alot of different brands in 40 years, don't get caught up on one forums Lab Tests as being the allmighty truth.Other then that you posted some Good information.

I'm not really invested either way, it was what came up after some searching and it helped make my point. For what it's worth, I don't think Home Theater Magazine is the same thing as Home Theater Shack, but I may be wrong. I haven't found anything from another source (because I always like multiple sources saying the same thing - so that credibility or personal bias isn't a problem (e.g. what you're talking about)) - if you have some actual numbers for any of the parts I've referenced, I'd be happy to revise the post. Most reviews seem to focus on how poetic the amplifier is though (I know Stereophile does bench-test, but Stereophile is equally contested, and generally only tests esoteric equipment).
 
#40 ·

Quote:
Originally Posted by walbert /forum/post/20732361


I'm not really invested either way, it was what came up after some searching and it helped make my point. For what it's worth, I don't think Home Theater Magazine is the same thing as Home Theater Shack, but I may be wrong. I haven't found anything from another source (because I always like multiple sources saying the same thing - so that credibility or personal bias isn't a problem (e.g. what you're talking about)) - if you have some actual numbers for any of the parts I've referenced, I'd be happy to revise the post. Most reviews seem to focus on how poetic the amplifier is though (I know Stereophile does bench-test, but Stereophile is equally contested, and generally only tests esoteric equipment).
My Bad getting old........... there was a post from the Shack that had the

same articles about Bench Tests on AVR and the member posts (I guess) were taken from this Magazine Site. I mean same articles.(figured they were the same maybe wrong) I have not posted over there in a year now.(Donald Trump remark over this topic) I will look for the emails from the other lab Test results on some of the same AVR that while all had lower WPC figures on 5 amps then 2 but higher WPC on the Yamaha AVR from what your link was..I made this same comment and the mods and owner of the site were rude about it(PM to me) and other Onkyo 805 posts I made.(ego remark) If it sounds good to me and my old Klipsch speakers and the AVR does not burn up HDMI parts every year I am happy. Lab #s really mean zip then. It's like Dyno # for my Corvette every magazine had different #s back them.....funny. That is why I said it was about the $$ on any lab tests on any topic. I like this forum a lot better, the members here will go out of their way to help.
 
#41 ·

Quote:
Originally Posted by Louis Bartay /forum/post/20732518

My Bad getting old........... there was a post from the Shack that had the

same articles about Bench Tests on AVR and the member posts (I guess) were taken from this Magazine Site. I mean same articles.(figured they were the same maybe wrong) I have not posted over there in a year now.(Donald Trump remark over this topic) I will look for the emails from the other lab Test results on some of the same AVR that while all had lower WPC figures on 5 amps then 2 but higher WPC on the Yamaha AVR from what your link was..I made this same comment and the mods and owner of the site were rude about it(PM to me) and other Onkyo 805 posts I made.(ego remark) If it sounds good to me and my old Klipsch speakers and the AVR does not burn up HDMI parts every year I am happy. Lab #s really mean zip then. It's like Dyno # for my Corvette every magazine had different #s back them.....funny. That is why I said it was about the $$ on any lab tests on any topic. I like this forum a lot better, the members here will go out of their way to help.

If I'm understanding you right, you're saying that the RX-A2000 has different numbers from different tests. That isn't entirely surprising - depending on how the test was set-up and run, especially the AC supply voltage and cooling, results can change a bit either way. With benchmarking in general, I generally consider results from one source to be comparable to different results from the same source - unless they give me a reason to believe otherwise. I'm not saying I would compare these values to values for different units from different sources though - that could get tricky (because again, if the tests are done differently you may not even be comparing the same thing).
 
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