Master Thread: Are Measurements Everything or Nothing?

[IPunchCholla]

I certainly can’t achieve a flow state if my boots and skis are off so equipment does matter as anyone who skis knows. . It is certainly something that some professional phycologists and professional musicians and skiers believe in. The truth sometimes lies when science meets art given the complexity of humans which we can’t fully measure and sometimes it is helpful to see the world through different perspectives. Again I’m just merely postulating that there might be human subjective factors when it comes to listening to music given that we are not all machines who are exactly the same.

Flow state exists. Listening to music literally requires no reproduction equipment to reach it, in the case of live acoustic music. It totally rests on the listener. It’s a bad analogy.

 

[antcollinet]

yet our measurement tools "hate" them.

Measurement tools neither hate nor love. They just measure - in this instance telling us whether or not 2nd (or 3rd etc) harmonics exist and at what level.

 

[Buckeye Amps]

Measurement tools neither hate nor love. They just measure - in this instance telling us whether or not 2nd (or 3rd etc) harmonics exist and at what level.

This.

The last few days of discussion have been mixing measurements with preference. There is absolutely nothing wrong with preference. Listen how you like, where you like, with what medium you like. Measurements are not concerned with how the end user chooses to listen, they are concerned with showing an objective baseline of performance so one can judge how well said component was designed/engineered/implemented.

 

[krabapple]

Not that this adds any testing but…

Indeed, but...

I perceive vinyl playback in my system (and some others) as having an added texture that makes the sound seem a bit more present and palpable, more solid. It’s very much like the texture added by my tube preamp that does the same type of thing.

Have you ever digitized the TT pre or tube amp outputs to see if this distortion sauce can be captured?

If I listen to the digital counter part to vinyl (or my Benchmark preamp vs my tube preamp), I can actually perceive more nuance and detail in the digital. But the end result is that both tube preamp and vinyl sound a bit more “real” to me in terms of painting, a slightly more solid and vivid picture of the sound.

Then again, it's sighted listening.

 

[krabapple]

@TTT15 the more you write, the more you show us that you don't know what you are talking about.

The flight of ideas is remarkable even for ASR.
Whether TTT15's measurement-agnostic consumer realizes it, their recorded music delivery system was likely engineered by people who were rather interested in objective measures of performance. The designers of iPhones don't just slap random components into them. This follows on from my previous point, that to a large extent today, the ability to provide 'hi fi sound reproduction' is built in. So whether they 'care' or not, they'll take it and like it.

 

[MattHooper]

Have you ever digitized the TT pre or tube outputs to see if this distortion sauce can be captured?

No, but of course any vinyl distortion could be captured digitally.

Then again, it's sighted listening.

Yes caveats apply as always.

(Though as I’ve written about before here, I did hear these characteristics in my tube preamp vs the benchmark in blind tests).

 

[Dan Lavry]

This.

The last few days of discussion have been mixing measurements with preference. There is absolutely nothing wrong with preference. Listen how you like, where you like, with what medium you like. Measurements are not concerned with how the end user chooses to listen, they are concerned with showing an objective baseline of performance so one can judge how well said component was designed/engineered/implemented.

My perspective (audio converter designer)

People listening to early converters (high distortions, noise, phase…) created the notion of “converter sound” (accepting distortions). This led to frequent discussions about which converter sounds better and why.

But an accurate converter is a converter with “no sound”. There is a lot of gear (analog, digital, DAW) to alter sound. A converter is no EQ or reverb…

A converter is not a triode tube. The claim is that a triode asymmetrical transfer curve causes some even harmonics. The harmonics falls on octaves of the fundamental. I think the explanation leaves a lot to be desired, but emulating a triode tube sound on a DAW can give everyone a tube sound and so much more.

I wish people realize that digital is done for utility (memory, internet…) things that can’t be done with analog. Conversion, like other some other gear is about accuracy, and it is measurable.

 

[MatrixS2000]

I wish people realize that digital is done for utility (memory, internet…) things that can’t be done with analog. Conversion, like other some other gear is about accuracy, and it is measurable.

Agree! Digital audio production >>>> analog audio production. When stacking modules in an analog chain, each module adds noise, distortion, etc and has limited headroom. Not so in a 32 bit float digital world. Since each module is executing mathematical calculations to change the sound it is not vulnerable to the same cumulative noise problem found in the analog world and the 32b float environment provides large headroom space without the same clipping/quantization constraints that a fixed point digital environment would have.

 

[Dan Lavry]

Agree! Digital audio production >>>> analog audio production. When stacking modules in an analog chain, each module adds noise, distortion, etc and has limited headroom. Not so in a 32 bit float digital world. Since each module is executing mathematical calculations to change the sound it is not vulnerable to the same cumulative noise problem found in the analog world and the 32b float environment provides large headroom space without the same clipping/quantization constraints that a fixed point digital environment would have.

True, digital processing power offers great advantages over analog. The basic material is only as good as the AD can provide (around 21 real bits so far), but the need for digital precision (such as 48 bit fixed or 32 floating) has to do with processing and truncation (during processing), a whole other subject…

The big analog shortcoming for me is lack of analog memory. Vinyl and tape are very limited (small sequential memory). Digital tiny memory with low power consumption can store a lot of music on a phone, memory stick, hard drive, youtube video’s and more. It enable editing and processing in non real time.

Also, digital offers a lot of noise immunity from interference, It can be sent over internet, music files can be easily duplicated.

Analog work is limited to real time processing. Digital offers utility, it is not about sound, it offers the ability to process sound in "not real time".

 

[Dan Lavry]

I see a number of software applications for tube emulation on DAW. Some show the triode tube curves to choose from.

A way to emulate curve is using Taylor series:

Vout = a0 + a1*Vin + a2*(Vin)^2 + a3*(Vin)^3 + ….

The more terms you add, the better the curve approximation.

Ao is DC level. For a single tone, a1 is signal amplitude, a2 add 2nd harmonic, a3 adds 3rd harmonic...

The tube transfer curve is asymmetrical, generating even harmonics (in phase with fundamental) , and the theory works for a single tone. Even harmonics fall on octaves. That adds to the fundamental tone sound, but does not sound like a distortion.

But all triode tubes came with a transformer (between the anode and the high voltage DC supply). Transformers have a symmetrical transfer function, thus the distortions are odd harmonics (out of phase with the fundamental). Driving a larger signal tends to increase the third harmonic. The transformer driving the speaker may becomes a real factor.

The issue is when you have 2 or more tones at different pitch. Unlike a single tone case there are inter-modulation distortions (sums and differences of the individual frequencies… energy that does not go with the music).

Lucky me, I am in the business of accurate linear transfer, conversion with minimal distortions and sonic alteration. It is up to the music producers to take it from there.

The word is mostly about simple linear transfer function, analogous to a flat mirror (I Know, reversed) or a “straight line”. It is the simplest and clearest way to go and work with.

Most amplifiers are not made of tubes. But I wonder about the person at home using a tube amplifier to listen to vinyl, CD of file with music already altered to include tube sound. Do they hear tube square? Should they switch to a semiconductor power amplifier?

I wonder what “ear people” think bout my comments. I have no hand on experience with DAW tube emulators.

 

[solderdude]

We fully understand why that is the case.
Your inner ear contains a tapered ribbon called the basilar membrane. It's stiff at one end and floppy at the other. Different spots physically resonate at different frequencies. Hair cells sit on each spot and fire a nerve when their frequency shows up. So your brain doesn't receive a waveform. It receives a live map of which frequencies are present. This layout is preserved all the way to your auditory cortex. You literally have a "piano keyboard" of neurons in your head.

Here's the key part. The 2nd harmonic is exactly double the fundamental's frequency. That means every peak of the higher wave nests perfectly inside every other peak of the lower one. On the basilar membrane the two spots that light up overlap heavily, and the nerve firings arrive at the brain perfectly synchronized. The signal is redundant, not new. Your brain reads it as "more of the same note." That's what an octave is, neurologically.

Even harmonics (2nd, 4th, 6th, 8th) all nest cleanly this way. Odd harmonics don't. The 7th in particular lands between piano keys, so it excites a separate spot on the basilar membrane your brain doesn't group with the original note. When the two spots are close but not aligned, they physically interfere on the membrane and produce roughness.

On top of that, 2nd order harmonics are incredibly hard to hear in the first place. There's another mechanism called auditory masking: a loud tone drowns out quieter tones that are close to it in frequency, and the 2nd harmonic sits right in that masking zone. So the fundamental literally hides its own 2nd harmonic. In Geddes' tests, people couldn't hear distortion on a 120 dB compression driver because the fundamental was masking the 2nd order harmonics entirely. Odd harmonics sit further away in frequency and escape the masking, which is another reason they stand out as harsh while even harmonics quietly disappear into the note.

So basically, probably you are not even hearing second order harmonics of a tube amp unless it is ridiculously distorted. And if the tube amp is incredibly distorted, we understand why second order or generally even order harmonics sound better.

Yep... and with harmonic distortion there also is IM distortion which, when not masked and loud enough, is not 'pleasing'.

 

[Audionaut]

Science needs to be applied to any reported subjective observations.

Yes, that’s the way.
If every ASR member were required to include their own hearing test results—measured using scientifically validated methods—in their signature, we could very quickly dismiss statements like “But I clearly heard those nuances in the crystal-clear high-frequency range” as nothing more than personal fairy tales.

 

[Audionaut]

By now, I’m downright allergic to that kind of audio garbage:
"To ensure that the vocals and guitar in 'Small Things' (album: I Forgot Where We Were) feel so tangibly present right in front of the listener, an amplifier must not pour any 'flattering sauce' over the music. It must focus on the essentials—the soul and the body—harmonize them, and present them without any effects—a shining moment for the NAD C3030! How perfectly confident it is tonally on the very slightly charming, minimally warm, yet at the same time unadulterated side of ‘neutral’ is, for me, truly top-notch in this class. Only the aforementioned Leak Stereo 230 (around 1,500 euros) comes close to this ‘midrange grip,’ but doesn’t surpass it by a significant margin. Sam Fender’s “People Watching” (album: People Watching) takes on a thoroughly charming appeal through the NAD C 3050’s even warmer midrange, because the vocals here exude a somewhat “cozier” aura. "

Bjørns Vermächtnis

Bei allem Retrocharme, den der NAD C 3030 optisch zur Schau stellt, ist er in technischer Hinsicht selbstverständlich ein Amp auf der ...

www.fairaudio.de

Terrible
The worst part is that almost all audio sites write such nonsense.

 

[solderdude]

Yep, they need to go with the flow if they want to keep selling 'sound improvements'.

 

[Dan Lavry]

The 7th in particular lands between piano keys, so it excites a separate spot on the basilar membrane your brain doesn't group with the original note. When the two spots are close but not aligned, they physically interfere on the membrane and produce roughness.

Your comment about the 7th harmonic is right on target.

The even harmonics fall on octaves. The odd harmonics can be off relative to the piano scale (twelve root of 2 spacing). The third harmonic is -1.6 cent, the 5th harmonic is +13 cents, the 7th is +30 cent, the 9th is -4 cent…

I would think the 5th is bad enough, but the 7th wins the distortion race. You play A2 (110Hz) and the 7th fall on 770Hz but the piano closest note is 783.991Hz, almost 14Hz off (while the next note is only 46.7Hz higher).

Funny thing, about tubes: a non linear “curved” transfer function (say power amplifier) becomes more linear when using a smaller portion of that curve. In other words, you get more distortions (tube sound) at higher volumes (large signal peaks and deeps use more of the curve).

Reducing the volume way down will remove much distortion (tube sound). I wonder how many audiophiles know that simple fact.

 

[Audionaut]

Reducing the volume way down will remove much distortion (tube sound)

Or you can use high-efficiency speakers that allow the tube amplifier to maintain low distortion levels even at objectively higher volumes.

 

[MaxxC]

Seems like so many review threads get challenged with:

1. Measurements are not everything.

2. You all never listen.

3. I trust my ears, not graphs.

4. I don't listen to graphs. I listen to music.

5. You all must not listen to music at all.

6. Why don't you all buy the best SINAD gear?

7. I have heard your best SINAD gear and they sound terrible. I don't like any of this Chinese stuff.

8. You don't trust your ears. I/we do.

9. All these reviewers/youtubers/audophiles say these amps, DACs, etc. sound different and you say they don't. They can't all be wrong.

10. Surely designers have created certain house sound for each equipment which your measurements don't show.

11. Your measurements are only at one frequency. You need to also measure X, Y and Z like impulse response, slew rate, etc., etc.

12. You guys run a cult here where you only go by measurements and no one is allowed to disagree.

On and on...

I have had to answer these so many times that I thought it is time to stop having them go into every review as they are not product specific. From here on, any such questions should be posted here. Answers will be given in this thread and simply referenced in future challenges in other threads.

Thanks. You all are free to discuss this topic, provide answers, argue, whatever, in this thread.

They are very important in designing a speaker. Measuring with pink noise and standard protocols invented in the 1960’s has little correlation with how they sound in the listening room. They are measuring and testing differently and it’s way more sophisticated. Measurements are only a part of the their equation. Ultimately their goal to build a good speaker for real world conditions. That can only be determined by listening.

 

[MAB]

They are very important in designing a speaker. Measuring with pink noise and standard protocols invented in the 1960’s has little correlation with how they sound in the listening room. They are measuring and testing differently and it’s way more sophisticated. Measurements are only a part of the their equation. Ultimately their goal to build a good speaker for real world conditions. That can only be determined by listening.

 

[krabapple]

They are very important in designing a speaker. Measuring with pink noise and standard protocols invented in the 1960’s has little correlation with how they sound in the listening room. They are measuring and testing differently and it’s way more sophisticated. Measurements are only a part of the their equation. Ultimately their goal to build a good speaker for real world conditions. That can only be determined by listening.

So what are you saying? There's something they measured but failed to take into account (.ie. it was measured, but ignored) ? Or they measured it wrong? Or they are listening for something that can't be measured?

 

[MAB]

So what are you saying? There's something they missed in their measurements and failed to take into account? Or they measured it wrong? Or they are listening for something that can't be measured?

A review of his posts to date is the typical audiophile word-salad of cables, electronics burn-in times, and insults to other members. I thought this one was a joke, until I read more.

A digital power cord is just a power cord that shields against digital interference. Other then any its no different then any other cord.

He is quite the of the defender of the kingdom of woo-woo, with incredibly thin skin and a bit of a toxic edge.