Why Some Audiophiles Fear Measurements

[Phelonious Ponk]

Good, perhaps, but not great. Neither objectively (as measured) nor subjectively (you have to hear the difference to appreciate it). Not sure if that's what you meant.

No, you got it, and we agree. Treatment is important. But I think Ethan overstates it, perhaps intentionally.

P

 

[kareface]

And do not forget to unlock your head out of the vice before you get up from your sweet spot, you might hurt something otherwise!

Hate when that happens.

 

[Robh3606]

I am not sure why folks are getting wrapped around the axle on this one.

We are talking about frequency response here, aren't we?

I will take a stab at it. For one thing you are using log power ratios that on a case by case basis may have nothing to do with how audible it is or how important it is to the overall system performance. A simple case in point would be a sharp narrow-band suck-out in the bass region say 20 dB deep. Depending on where it is it may be very tolerable. Now take 6 db spike at say 4k. Which would you rather live with??

What percentage would one apply to this case stated above....30db is 1000times more effect when talking about radio power output.

It is irrelevant what matters is the audibility of the actual measured anomalies. General statements like that can be very misleading and are easily misunderstood because there is no context without specific examples. In this case measurements that could be used to determine the audibility of the anomalies.

Rob

 

[Mike Lavigne]

I am not sure why folks are getting wrapped around the axle on this one.

We are talking about frequency response here, aren't we?

Forgetting about your vinyl cartridge frequency response (but some are within less than 1 db for sure)

phono frequency response ie riaa, say 0.1db

pre-amp frequency response, say 0.1db

power amp frequency response say 0.5 db

speaker frequency response say 10db

what you measure at your ear after that accumulated 10.7db frequency response aberattion is now also due to the room having 30db peaks and valleys

I would say strictly speaking, frequency response wise, 30db is a bigger number than 10.7db. Especially in as he states, where the effect is most pronounced, in the base range.

I do not see the huge problem with what Ethan stated, as stated, as far as effect to frequency response. What percentage would one apply to this case stated above....30db is 1000times more effect when talking about radio power output.

And do not forget to unlock your head out of the vice before you get up from your sweet spot, you might hurt something otherwise!

Cheers

Tom

well, you'd likely need a GPS to navigate thru Ethan's posts and track what he is exactly referring to with his ratios, but as best as i can tell he is referring to percentages of these items he refers to in post #454;

I don't know about meaningless, because frequency response is the best measure of tonal color. But I agree it's not the only thing. There are four parameters that affect audio reproduction:

Frequency response
Distortion
Noise
Time-based errors
Of course, there are subsets, such as hum and buzz and LP crackles under noise.

which he goes on to claim include everything needed to be considered here in the same post;

Often when I list my "four parameters," someone will say there's more to audio fidelity than that. But every time I ask what else there might be, I never get an answer. I am ready to accept that there's more to audio fidelity than these four parameters, as soon as I see credible evidence.

i'm not agreeing or disagreeing with Ethan on these 4 paramenters; just on how he assigns percentages of the total system performance. and if he was tongue in cheek i fail to see that. he did say he was being simplistic.

and so to respond to your post it's more than just frequency response we are talking about.

 

[Mike Lavigne]

Things can get a bit lost in this long thread for sure, Mike.

what long thread?

 

[The Smokester]

On THD vs. IMD: There is a relatively simple mathematical relationship that relates the two...:

2nd-order IMD (dB) = 2nd-order HD (dB) + 6.021 dB
3rd-order IMD (dB) = 3rd-order HD (dB) + 9.542 dB
...
FWIW - Don

Don, I don't understand these equations. If there is no 2nd-order distortion there is still 6.021 dB of IMD? How can this be?


On the other topic:
I took Ethan's weightings as a engineer's "Straw man". Namely, a starting point with clear reasoning used as a point of departure for discussion.

I guess I would quibble with the weightings. I would keep the logarithmic scaling with power that corresponds to the way we hear.

So, Cables and electronics are 1 dB; Speakers are 10 dB; and rooms are 30 dB.

That gives a weighting of Cables and electronics 2%; Speakers 24%; Room 73%.

Personally, I don't find this subjectively different from what Ethan originally said making his argument, so far, quite robust.

I don't think the intention of these weightings should be to directly apportion money to stereo components. They are, rather, estimates of each component's relative contribution to deviations from neutrality. Engineering-wise, one should pay whatever is necessary to make the contribution of each component equal.

PS: I left out 1% in the above numbers to give you guys that still want to argue about this a little wiggle room.

 

[Mike Lavigne]

diffusor looks nice Mike, had not noticed that before.

hmm, hope that laptop is for streaming and not measuring haha!

thanks. i've added some Auralex T-Fusor diffusors on the sides and ceiling since this picture was taken back in Feb of this year.

regarding the laptop; besides the obvious web-surfing and posting, the laptop is used as a remote control for my music server (Lynx AES 16XLR based) which is upstairs in the former hayloft. also; when doing speaker set-up i use a Phonic PAA3 RTA connected to the laptop with a long USB cord and sit behind the speaker with the laptop adjusting the speaker adjustments to get a flat response. so it is used for room/speaker adjustments. once close i do fine tuning by ear.

my son (a network engineer for the company i manage) is going to set up an i-Pad to replace the laptop as my server remote so i can turn the light on and off easier. i enjoy using the server but not the laptop screen and trying to reduce the light. it intrudes on the whole musical flow for me. we tried an i-Touch but it was not stable enough with the WiFi to work reliably. my son has set up an i-Pad for a friend and it works much better with Wifi.

 

[silviajulieta]

I agree that Ethan has overstated the importance of the room. Not that a really bad room can't ruin a great system, it can, but given a reasonably normal living space with rugs and some big soft furniture and a pretty normal mixture of hard stuff and soft stuff, a good system will sound good and a bad one will still sound bad. But this takes us back to the central point of subjective vs. objective, fear of measurements, whatever you want to call it:




That's a huge problem unless you're saying that Steve's Lamms have some really precise and powerful EQ built into them, because even if it isn't a pig, even if it Ingrid Bergman, it's still going to paint it with the same lipstick.

P

Dear Phelonious Ponk: You are right it has an EQ built into them in a form of very high output impedance:

Output Impedance
at 1 kHz


typically 6.2 Ohms; 16-Ohm tap.
typically 3.1 Ohms; 8-Ohm tap.
typically 1.55 Ohms; 4-Ohm tap.

and that's why happen what M. Lavigne posted. Those amps due to that high output impedance are highly colored running almost any speaker, instead to have a flat response are ( practically ) following the speaker electrical impedance curve as response. This is a clear example that speaks by its own on the importance of measurements/specs and why we have to be aware of that kinf of measures/specs.

Regards and enjoy the music,
raul.

 

[Mike Lavigne]

Mike, go back and read Ethan's original statement. It is a qualified one.

Those 450 watt Monos, maybe they can handle anything, maybe they can't. Maybe they would have more than a 1% effect in a positive way, maybe not. It does depend on a few things, doesn't it, including, for instance, at what level you are playing your music, what crest factor is in the track your playing, etc.

i would be shocked, shocked, if the dart monos could not handle any real world speaker system mentioned on this forum. but the whole amp thing was a sideline to my point anyway, so it's not worth getting that into the issue. there are quite a few amps which certainly contribute more than 1% of the performance of a system.

So in a thread about measurements, and in particular, why some audiophiles fear them, an answer which is nothing more than "I think" is insufficient and serves to bolster Jeff Fritz's position. Where is the data, as Amir likes to state, to support your position? "I think" is not data. It is not falsifiable. What you think, another is free to think the opposite, and neither of those thoughts can be examined. And that was PP's point.

fine. point taken.

As an aside, I also don't agree with Ethan's percentages. I agree with Chuck's (audioguy's). The room and speakers make up 95%, or 90%, or 85%, whatever, the vast majority. I would say, though, that the speakers and the room must be considered as one, inseparable, in this analysis.

i agree that the room and speaker are a team; although an uneven one. the speaker is dominant in the relationship. i view it as the room supports the speaker. then the amp-speaker 'team' must be considered when viewing the room. different amps would require different room-speaker adjustments.

if we look at amp-speaker-room i'm at about 70% to 80%

power grid 5% +

sources 10%-15%.

some systems could be 80% to 90% amp-speaker-room if the power and sources were very simple......just street power, digital only. higher performance power grid and more exotic sources take a system to higher performance and therefore are responsible for more of the performance envelope.

i'm simply relating my personal experience. i am speaking now of percentage of performance, not personal viewpoint on priorities. that is a whole separate line of discussion.

 

[The Smokester]

...i agree that the room and speaker are a team; although an uneven one. the speaker is dominant in the relationship. i view it as the room supports the speaker. then the amp-speaker 'team' must be considered when viewing the room. different amps would require different room-speaker adjustments.

if we look at amp-speaker-room i'm at about 70% to 80%

power grid 5% +

sources 10%-15%.

some systems could be 80% to 90% amp-speaker-room if the power and sources were very simple......just street power, digital only...

With respect, but do you realize that you and Ethan are using the same words but (probably) talking about two different things? You don't really define what your percentages are, or how you arrive at them, but I would speculate that they are somehow related to how you apportioned money or effort in setting up your system. Just a guess but the looseness of your talk leaves this reader, who is trying to understand this subject, guessing at what you mean. Ethan is talking about the contribution each component potentially can give to the quality of sound independent of money or effort. I can use what Ethan says because I can relate it to potential modifications to my system. I can't really use what you are saying unless my goal is simply to duplicate your system.

Perhaps it would help if you more clearly defined what your percentages relate to and described the process by which you arrived at them.

 

[microstrip]

All this arguing about percentages forgets the law of diminishing returns that makes all this process non-linear. As this law has different slopes when applied to speakers, amplifiers, cables, the wonder formula will be a function of the price of the system. Enough to keep a mathematician busy for a longtime...

As far as I know the systems that Ethan tries to model are in a completely different price range of those of Steve, Mike or even mine.

 

[Orb]

Originally Posted by DonH50
IMD is worse by 6 dB/9.5 dB than the 2/3-order HD term.

Awesome, thanks for that Don! I'm not a math guy, but this matches my empirical experience when I did circuit design stuff years ago.

So this is yet more evidence that specs giving only THD are incomplete, especially when said incomplete specs are used to suggest that two devices can measure the same yet sound different.

--Ethan

To be fair though Ethan IM distortion is incredibly more complex than just that when it comes to audibility and importantly the test protocol-procedure it is applied to.
Check the arguments on DIYAudio about IM Distortion

But going with IM distortion is a problem (beyond showing amp behaviour) then it is interesting what Nelson Pass has to say in his article relating to IM distortion:

Figure 7 (simple intermodulation distortion) shows a distortion waveform resulting from two tones passing through a gain stage with both 2nd and 3rd order nonlinearities having 1% coefficients.
The two tones have equal amplitude and they are one octave apart.
The signal peaks are about 1.8 volts, and the distortion peaks are about .09 volts, or 5%, and the ratio of rms averaged distortion divided by the rms signal is about 4%.
This distortion doesn't look so bad, but it is obviously higher and more complex than singletone distortion.

Let's see what happens when there are lots of frequencies involved.
In Figure 8 (complex intermodudulation distortion) we see a waveform consisting of 7 non-harmonically related tones of equal amplitude from 100 Hz to 2800 Hz.
If we run this signal through the same gain stage and subtract the original signal we get the distortion seen in Fig 8:
Not very pretty is it? Now the distortion is getting really complex, with lots of harmonics, and the peaks are up around .9 volts.
That's 11 times the .08 volt figure of the single tone, and the ratio of the rms distortion to the rms input signal is about 8%.

I appreciate I sound like a broken record but this supports my point that measurements are meaningless unless used in their correct context, meaning that too many times a simple test-measurement result is used for conclusive evidence either to make a point or part of a hypothesis.
I really do feel we can measure those factors in Jeff's article relating to resolution, transparency, soundstaging, imaging, etc.
However maybe this will not be possible until we use test protocols-procedures and tools that reflect the greater complexity of real musical notes (maybe such as a sustained major chord at different points on the musical scale although in reality we also need attack and decay).
To emphasise my point we have IM distortion as presented by Nelson in his article, where two tones may be enough to assist in seeing an amp behaviour or some potential problems but does not reflect the characteristic response with real musical notes from instruments.

Ethan, again I am smiling because at this point your going to go aha this proves all sound differences beyond FR relate to distortion; in a way its proving both our points so far.
But here is Nelson's closing comments (bearing in mind that he has looked at this in detail and applies this experience to building products).

If you want the peak distortion of the circuit of figure 13 to remain below .1% with a complex signal, then you need to reduce it by a factor of about 3000. 70 dB of feedback would do it, but that does seems like a lot.
By contrast, it appears that if you can make a single stage operate at .01% 2nd harmonic with a single tone without feedback, you could also achieve the .1% peak in the complex IM test.
I like to think the latter would sound better.

Full article here and suggest its worth a read even those marginally interested in this type of topic or measurements.
http://www.firstwatt.com/pdf/art_dist_fdbk.pdf

To me there is more to this than just the 4 parameters you feel explain audio production (Frequency response,Distortion,Noise,Time-based errors), which is why I feel your conclusions at the moment are incomplete, and on top of that it still needs to be shown how those 4 parameters correlate to what we hear (as I say using more than just tonal/bass description and include those more along resolution, transparency, soundstaging, imaging and several others as suggested by Jeff in his own anecdotal experience) between different products while being comparable to just your 4 parameters you mention for the measurements.
But importantly on top of this we are ignoring temporal related information-tests if focusing on your 4 parameters in your hypothesis of what we hear from audio reproduction, which again is a critical aspect that may have some implications on the area where some who describe what is being replayed back with the term musical.

Anyway Until you can correlate the measurements and products and listeners full perception of audio playback to your proposed 4 parameters it is just hypothesis, which unfortunately will not go any further as it seems you do not want to investigate the listener perception-hearing side as you feel its too subjective (bearing in mind as I said in the past HK/Toole/etc at some point in their investigation-studies do this).
This can be blind listening using the right procedures and protocols and nothing to do with ABX (abx in this instance would not be helpful and if necessary happy to expand on the reason in a different thread).
Still a pig to setup, but until then a step in that direction would be to take specific keywords relating to perception describing what we hear (used by the better reviewers such as the resolution, transparency, soundstaging, imaging along with others) and try to compare those across their many reviews to the products and measurements.
That is not conclusive but a step towards the blind listening protocol and would help as it narrows the criteria of products to use in such a test, until then your stuck in a hypothesis IMO just like me

Cheers
Orb

Edit:
Added an end paragraph after the Nelson link, just to provide a better wrap up from my end.
Also if I say "your 4 parameters" often it is not intended as an insult, just that I quote 4 perception descriptions from Jeff and did not want them to get blurred and confused as their context (parameter measured vs perception description heard) are different.
And also bear in mind Nelson's complex IM distortion test I think is way beyond any current IM distortion tests done by review publications and manufacturers (if someone knows differently more than happy for them to post a link to them as I would be curious).
And one last clarification, I do agree with you Ethan that distortion and FR may create and can affect a listeners perception for audio playback if those test measurements result in audible figures, but as an example the Nad and ARC should not due to very low figures where something else is occurring IMO.

 

[Orb]

.....

Hello Orb

Sorry I didn't mean to put you to work on that response I understand what you meant now thank you for the clarification.

Rob

Rob no need to apologise and glad that you raised it as I can definitely see looking back how it could had become confusing, had me laughing when I went back and found where I was quoted but reduced to only 7 words long and resulted in a totally different context that you may had read and others
Also I covered two different topics that included fear/indifference to measurements for many audio listeners and this adds to the difficulty to follow what I said

Thanks for the acknowledgement and hope my posts are ok to read
Cheers
Orb

 

[Mike Lavigne]

With respect, but do you realize that you and Ethan are using the same words but (probably) talking about two different things? You don't really define what your percentages are, or how you arrive at them, but I would speculate that they are somehow related to how you apportioned money or effort in setting up your system. Just a guess but the looseness of your talk leaves this reader, who is trying to understand this subject, guessing at what you mean. Ethan is talking about the contribution each component potentially can give to the quality of sound independent of money or effort. I can use what Ethan says because I can relate it to potential modifications to my system. I can't really use what you are saying unless my goal is simply to duplicate your system.

Perhaps it would help if you more clearly defined what your percentages relate to and described the process by which you arrived at them.

sorry; i don't have 'scentific method' in my signature......but to answer your question i'll copy my previous post where i did get into a bit more explanation of these areas, which i assumed a reader would be familair with since it was posted yesterday afternoon. this post was directed at Ethan.

one day spent at an audio show such as CES or RMAF visiting multiple rooms, all which are not ideal, few of which have any treatment, illustrates time and time again how careful set-up, excellent gear assembled synergistically, and great sources and recordings can result in very good sound. if a room was 90% of the performance then these rooms would sound like crap. some do sound like crap, but many sound good, and some sound wonderful.

not objective enough approach for you? how do you know that? have you measured these rooms and compared them to an 'Ethan' approved room? and then had listeners offer their subjective viewpoint on whether these 'best of audio show' rooms sound better or worse than the rooms you help.

forgetting about controversial issues such as cables and tweaks; there are many aspects to any system performance that end up being significant in the final level of performance.

it starts with the quality of the power grid. how clean is the power? this affects noise floor and dynamics, as well as the performance of every step in the signal path.

source gear quality as well as importance of the format and software/performance. really; the very best recordings somewhat trump everything. crap in-crap out. sometimes you would rather not hear everything that marginal recordings can tell you. i'm trying to stay away from the whole analog-digital issue for sure; but at a show, when the rooms all sound the same to a degree, a great analog recording raises the level of performance of a room.

amplification. Steve's Lamm ML3's can actually put lipstick on a pig. to say that it's contribution is less than 1% to the audio reproduction is an absurd statement.

finally; speakers are easily more than 9%. whether it's 20% or 50% is a question, but whatever it might be (and it likely varies from system to system) it's more significant than you suggest. if one listens at modest SPL's and the room is reasonably sized, the room's significance is reduced and the speakers are increased. i've heard magical systems in small rooms that look like they cannot sound as good as they do.

then i amended my amplifier reference due to a perception of coloration with the ML3.

fair enough. i choose Steve's ML3's to avoid anything personal for me in my response. let's go ahead and substitute the darTZeel amps; either my own NHB-108 or, the NHB-458 monoblocks, for the Lamm ML3's. i included both amps since there are speakers that could be a bit too tough a load for my Stereo darTZeel....whereas the 450 watt Monoblocks can handle anything.

i think either of these amps would make a much larger than 1% effect in a positive way on a system.

i'm happy to expand on the above descriptions but it will be full of subjective descriptors as that is how i communicate.

as far as the process of realization about how these things effect the performance it is from listening as changes are made in my system and judgeing subjectively what contributes to my viewpoint of overall performance.

sorry if i'm a bit testy but i think your point is a bit trivial. power grid, sources, and amp-speaker-room are quite self explanatory. if i've missed the point of your comment than i apologize. please expand a bit and i will take another shot at it.

 

[RBFC]

While the various "weightings" that have been assigned to room, speakers, and electronics make for an interesting and lively discussion, it's not quite as simple as that. If the preamp is functioning, but is noisy and has poor electrical performance, then the result will surely be less than the 99% figure that would be left. If the speakers are a crappy old pair of bookshelf models, then the result may well be far less than 90% of ideal. If you listen at a maximal volume of 80-85dB, then both your room and speakers (volume capability and bass performance) may not be such contributing factors to the sound. If you listen much louder..... you get the point. It's very dependent upon the performance requirements of the system to its listener. If you have a good system, say some Sashas (or similar sized speakers) and fine electronics in a room that is 60' x 60' x 12', first reflections are moot in a time-based analysis. Therefore, the relative contribution of room treatment depends upon the physical dimensions of the room, its construction materials, and the location of the system with respect to room boundaries (among other factors.)

Why don't we re-approach this situation by placing % figures on the choice of equipment, then assigning an incremental % increase in sound quality due to room treatment. One might develop "modifiers" that attempt to address different size rooms and types of music played (which describes how important certain parameters are to audible performance.) This seems like a more intelligent means to go about this. IMO, a home-theater-in-a-box will still sound lousy in a good room. On the other hand, great systems can sound very good in an average room with detailed attention to setup and placement.

Can we neglect the room? NO. However, I'm not convinced that one can throw virtually any components together haphazardly and expect good sound in any room. There is a more intelligent method to address a complex issue. Someone who listens only to chamber music will probably not be bothered by a room that has 30 dB swings in the lower bass range. Ditto for acoustic guitar. (Of course, the sound would be even better in a treated room, but not 90% of the end result.)

I hope my line of reasoning is clear.

Thoughts?

Lee

 

[Phelonious Ponk]

While the various "weightings" that have been assigned to room, speakers, and electronics make for an interesting and lively discussion, it's not quite as simple as that. If the preamp is functioning, but is noisy and has poor electrical performance, then the result will surely be less than the 99% figure that would be left. If the speakers are a crappy old pair of bookshelf models, then the result may well be far less than 90% of ideal. If you listen at a maximal volume of 80-85dB, then both your room and speakers (volume capability and bass performance) may not be such contributing factors to the sound. If you listen much louder..... you get the point. It's very dependent upon the performance requirements of the system to its listener. If you have a good system, say some Sashas (or similar sized speakers) and fine electronics in a room that is 60' x 60' x 12', first reflections are moot in a time-based analysis. Therefore, the relative contribution of room treatment depends upon the physical dimensions of the room, its construction materials, and the location of the system with respect to room boundaries (among other factors.)

Why don't we re-approach this situation by placing % figures on the choice of equipment, then assigning an incremental % increase in sound quality due to room treatment. One might develop "modifiers" that attempt to address different size rooms and types of music played (which describes how important certain parameters are to audible performance.) This seems like a more intelligent means to go about this. IMO, a home-theater-in-a-box will still sound lousy in a good room. On the other hand, great systems can sound very good in an average room with detailed attention to setup and placement.

Can we neglect the room? NO. However, I'm not convinced that one can throw virtually any components together haphazardly and expect good sound in any room. There is a more intelligent method to address a complex issue. Someone who listens only to chamber music will probably not be bothered by a room that has 30 dB swings in the lower bass range. Ditto for acoustic guitar. (Of course, the sound would be even better in a treated room, but not 90% of the end result.)

I hope my line of reasoning is clear.

Thoughts?

Lee

Clear and reasoned. In a near-field configuration, listening at moderate volume, you need little more than either plenty of space behind you or a reasonably soft back wall to get very good sound from very good equipment. In a big glass, brick and tile room, with big speakers and a listening position 10 feet back, you're going to need an acoustics consultant. As is almost always the case, it depends...

P

 

[The Smokester]

sorry; i don't have 'scentific method' in my signature......but to answer your question i'll copy my previous post where i did get into a bit more explanation of these areas, which i assumed a reader would be familair with since it was posted yesterday afternoon. this post was directed at Ethan.



then i amended my amplifier reference due to a perception of coloration with the ML3.



i'm happy to expand on the above descriptions but it will be full of subjective descriptors as that is how i communicate.

as far as the process of realization about how these things effect the performance it is from listening as changes are made in my system and judgeing subjectively what contributes to my viewpoint of overall performance.

sorry if i'm a bit testy but i think your point is a bit trivial. power grid, sources, and amp-speaker-room are quite self explanatory. if i've missed the point of your comment than i apologize. please expand a bit and i will take another shot at it.

Mike, Thank you so much for taking the time to respond. Reading through your posts again was just as enjoyable and informative as the first time. You have every right to be testy. I would be too.

If I said I was 90% certain that we are talking past each other would I make the point more clear?

 

[silviajulieta]

Inspired by a true story . . .

http://www.ultraaudio.com/index.php...-fear-measurements&catid=25:opinion&Itemid=27

Dear Jeff: There is no doubt that your thread makes that all of us " think " in audio system/items measurements/specs even if " we don't care in anyway on measurements/specs "., thank's for that.

This " think " sole fact IMHO made the threatd worth been posted. I think that many of us have a different " picture " of why is important to " think " on measurements/specs and that those measurements/specs can't damage each one audio system: we don't have to have any fear then.

Now, there are measurements and measurements, some could means/help a lot alone and some needs a set of mesures to make sense. I think that many of us don't want to be experts on measures but only take it as good choice tools.

Through the thread we read what some measurements/specs like FR, output impedance, RIAA , IMD , matching impedances or THD shows up: I would like to ask you ( because IMHO it is an important whole subject ): which and the why are those measurements/specs where we audiophiles have to put the " eye " ( with out to be experts. In what we have to focus other that listening. ) that could help to make better audio system choices with different audio links: amplifiers, speakers, phono stages, preamps and the like.

Could you share with us your knowledge about?.

Thank you in advance.

Regards and enjoy the music,
Raul.

 

[Ethan Winer]

For me measurements should report numbers and units, but the conditions of the measurements have to be clearly specified. Unhappily at previous posts I can only see very few quantitative values. But one of them is -80 dB for all distortion in amplifiers as threshold for being not audible. At what power and with what signal should we measure it?

Yes, complete data requires a lot of numbers and conditions to be reported! But the -80 figure I mentioned is mostly level-independant. That is, at a low volume you might not notice distortion even if it's only 30 dB below the music, but at high levels -80 is soft enough not to hear it. So consider -80 as a worst-case condition for "transparency."

--Ethan

 

[Ethan Winer]

ok, i'll bother

Thanks. This is vastly better than just saying only "I disagree" as so many others do.

one day spent at an audio show such as CES or RMAF visiting multiple rooms, all which are not ideal, few of which have any treatment, illustrates time and time again how careful set-up, excellent gear assembled synergistically, and great sources and recordings can result in very good sound. if a room was 90% of the performance then these rooms would sound like crap. some do sound like crap, but many sound good, and some sound wonderful.

I don't think it's fair to consider the quality of the recorded music because that's outside of the gear. A good recording will sound good on a cheap boombox, and a crap recording will sound like crap on the best system in the best room. I do agree about the importance of placement, but that's a "room" issue because it's also outside of the gear, and is entirely a function of room reflections. If not by adding absorption or diffusion, then by controlling the peak / null strengths and reflections by changing angles and speaker and listener placement.

have you measured these rooms and compared them to an 'Ethan' approved room? and then had listeners offer their subjective viewpoint on whether these 'best of audio show' rooms sound better or worse than the rooms you help.

I've measured a lot of rooms including hotel-size spaces, and I've heard a lot of audio show hotel rooms. The better ones at least have curtains in the right places to tame the worst of the reflections, if this is what you're asking.

forgetting about controversial issues such as cables and tweaks; there are many aspects to any system performance that end up being significant in the final level of performance.

Okay, but we were talking about frequency response. Even if we include everything that affects the sound, what do you consider "significant" in a system? Not "power amps" or "speakers" but actual parameters expressed as dB or distortion amounts etc.

it starts with the quality of the power grid. how clean is the power? this affects noise floor and dynamics, as well as the performance of every step in the signal path.

This is a perfect example of why I ask for dB values. Saying power is important doesn't really say anything at all. Now, if you said, "A typical receiver has a noise floor at 100 dB when using normal AC power, and that can be reduced by another 3 dB with a power conditioner," then we'd have something to discuss. I'd probably say that 100 dB is already soft enough that another 3 dB doesn't matter much. And you might rightly counter that noise at -100 dB could be audible on soft passages at very high SPL levels. At least then there's something tangible to discuss.

Steve's Lamm ML3's can actually put lipstick on a pig. to say that it's contribution is less than 1% to the audio reproduction is an absurd statement.

Is that a power amp? If an amplifier changes the sound enough to make music sound noticeably "better" than other amps, that seems more like a euphonic effect. So then it's like saying that adding an EQ affects the sound more than 1 percent, which in turn depends on how much EQ is actually applied.

At this point I remind everyone that I did qualify my ratio as simplistic, and I also added a smiley underneath.

speakers are easily more than 9%. whether it's 20% or 50% is a question, but whatever it might be (and it likely varies from system to system) it's more significant than you suggest.

I explained pretty clearly how I arrived at my 90/9/1 percent figures regarding frequency response (only). I'll be glad to see the logic behind your "more than 9 percent" figure.

--Ethan