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Any correlation between measurements and perceived sound quality?

bravomail

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I had very bad experience with SMSL Idea/Sabaj Da2 which measured very good in Amir tests. I think it simply does not have enough power to drive my AKG K7xx, and it sounds harsh. When paired with Schiit Magni 2 and at default volume setting it cannot provide enough volume. Every time you unplug SMSL Idea - it will reset its volume to default level, hence I tried it at that unfortunate setting. I have Hifime Sabre 9018 dongle USB DAC, with similar form factor to SMSL Idea, which ironically measured bad/so-so in Amir's testing. But, it drives AKG K7xx without issues, it doesn't have useless volume buttons, it pairs with Schiit Magni 2 just fine (you probably won't need it).
All above simply tells me that methodology of testing and the parameters tested need to be reviewed. What is being presented - does not provide the whole picture.
 

graz_lag

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I had very bad experience with SMSL Idea/Sabaj Da2 which measured very good in Amir tests...
... All above simply tells me that methodology of testing and the parameters tested need to be reviewed. What is being presented - does not provide the whole picture.

Have you not realized yet that if you buy Chinese made items you may suffer issues related to their poor QC protocols ?
Are not @amirm methodology of testing and the parameters tested that need to be reviewed ... But rather those associated to the QC in these Chinese plants ... :rolleyes:
 
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Wombat

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King Amir and his loyal servant Sir Thomas. Makes perfect sense to me. I believe the jury's still out on whether Sir Thomas is a black knight or a white knight.

Plaster dust makes him white, either way. :rolleyes:
 

GGroch

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..........Sound production does come down to voicing. Some amps I have sound better (to me) with same source and speakers. Why is it that there is over emphasis on numbers?
This thread started when I read this post https://www.audiosciencereview.com/forum/index.php?threads/hardware-mods-the-ugly-story.3619/
........I have heard to modwright modded oppo blu-ray players, they probably do not measure greatly but they definitely sound very good compared to non-modded. But again, this is all perception.

Thank you for starting this thread and posting the link. My take on the linked article is I think totally at odds with yours.

Very few modders tweak products to change the voicing knowing it will negatively impact accuracy & measurement. Even fewer would admit to it in their sales pitch. Instead they will talk about how their upgraded improved components produce even greater fidelity, a more accurate reproduction that go beyond what we currently can measure. "We're making it better in ways we cannot yet understand" not "We're making it worse but more pleasing"

It DOEs sound better to the new owners because they have invested in the mod (monetarily and intellectually). This does not make them stupid, it is how our minds work. This is what solderdude's much repped post #2 is talking about. To go back to your 1st post...If you did not know what "Class D" meant or that an amp had it, it will sound different to you than if you do. In most cases we get what we expect. Certainly a gorgeously constructed Levinson amp may be audibly different from a new Class D, but if it is, that would show up in measurement.

Our perception of that difference is a whole new thing. It is a combination of what we actually hear, and how we feel about the product. If an amp measures perfectly, then what class it is will not impact a blind test. It will only impact sighted tests where you know the technology and have an opinion on it.

That said...all of our normal listening is sighted. I just got a JDS Atom headphone amp that measures almost perfect...and to no surprise it sounds great to me. How could it not. But I also just got a Loxjie P20 (part of bravomail's dredded SMSL/Sabaj family). It is a tube hybrid design, and because of that it will almost certainly measure worse. However, I like tubes, I expect them to sound warmer and more musical. This one sounds great to me. I will not be surprised when Amirm's measurements show it is not perfect. When I see the measurements I will have a better idea of whether my positive opinion of the P20's sound comes more from my ears or my preconceptions. If it measures perfectly, the warm sound is all in my head. If not, perhaps I hear some of it. That's fine, I like the tube glow.
 

SIY

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It is a tube hybrid design, and because of that it will almost certainly measure worse.

Maybe. Maybe not. Some tube designers actually engineer their circuits (I'm unfamiliar with the Loxjie) so that the distortion is as low as what people attribute to solid state.
 

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March Audio

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I had very bad experience with SMSL Idea/Sabaj Da2 which measured very good in Amir tests. I think it simply does not have enough power to drive my AKG K7xx, and it sounds harsh. When paired with Schiit Magni 2 and at default volume setting it cannot provide enough volume. Every time you unplug SMSL Idea - it will reset its volume to default level, hence I tried it at that unfortunate setting. I have Hifime Sabre 9018 dongle USB DAC, with similar form factor to SMSL Idea, which ironically measured bad/so-so in Amir's testing. But, it drives AKG K7xx without issues, it doesn't have useless volume buttons, it pairs with Schiit Magni 2 just fine (you probably won't need it).
All above simply tells me that methodology of testing and the parameters tested need to be reviewed. What is being presented - does not provide the whole picture.

Your AKGs are not difficult to drive. 0.64 mW to achieve 90dB (think that's about 200mV) and a benign 66 ohm impedance curve.

They might be a bit brighter than a typical reference such as the HD650.

If the smsl and sabaj measured well (I haven't checked) then I doubt your conclusions have anything to do with the performance / sound of the smsl

https://www.google.com.au/url?sa=t&...FjABegQICBAB&usg=AOvVaw2MaPZ1TYbjXxSIQmAhDDZw
 
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March Audio

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OK looked a bit more into this, the measurements show that the sabaj can only drive to about 1v rms output before distortion increases, The smsl to about 1.25 vrms. This is a low output level and would only get the AKGs to about 97 - 98 dB. If you turn it up beyond that it probably will sound harsh due to the distortion. These are portable devices with limitations.

So basically the measurements DO tell us what we need to know, it's about understanding and interpretation. Nothing wrong with Amir's methodology.
 
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tomelex

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I strongly suspect that there's more to the sound of DHTs than just the harmonic spray. Here's an easy experiment that I did some years ago: set up a DHT gain stage and don't connect anything to the input. Put a spectrum analyzer across the output. Now using a different amp, play some pink noise. Note what happens on the spectrum analyzer. A swept sine and an oscilloscope will give a less quantitative but equally enlightening result.

Yes agreed, there are several factors, mechanical and electrical interactions going on there, but for the scenario I layed out the spectrum is enough to help correlate that one would like the replacement amp as opposed to say a normal voltage feedback solid state amplifier. DHT and me go way back and for less complex (non symphonic) music I appreciate what they do to help out plain old stereo. Your post is appreciated and enlightening for those seeking the "why".
 

solderdude

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One aspect that could destroy the reputation of perfectly fine measuring/operating gear is incorrect usage.
A few examples below.
  • Mild clipping of headphone output stages, voltage and or current limits being reached.
  • High source output voltages saturating input stages of following equipment.
  • Too low source voltages or too low gain somewhere preventing enough output power.
  • Incorrect usage of software EQ (gain not reduced when boosting frequencies)
  • Poor quality source music used
  • Headphones connected to not well suited amps.
  • Operational errors from the user.
  • Incorrect settings used
  • Defective components that don't produce grave distortion etc.
  • Far from ideal transducers (speakers/headphones) being used.
  • Taste / personal preference of the owner not matching that of the used transducers
  • Room acoustics / placement
  • Seal leakage using headphones
  • Having unrealistic expectations
  • Incorrect remembering of tonal aspects from other gear
  • (Small) level differences during comparisons
 
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Headphonaholic

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I had very bad experience with SMSL Idea/Sabaj Da2 which measured very good in Amir tests. I think it simply does not have enough power to drive my AKG K7xx, and it sounds harsh. When paired with Schiit Magni 2 and at default volume setting it cannot provide enough volume. Every time you unplug SMSL Idea - it will reset its volume to default level, hence I tried it at that unfortunate setting. I have Hifime Sabre 9018 dongle USB DAC, with similar form factor to SMSL Idea, which ironically measured bad/so-so in Amir's testing. But, it drives AKG K7xx without issues, it doesn't have useless volume buttons, it pairs with Schiit Magni 2 just fine (you probably won't need it).
All above simply tells me that methodology of testing and the parameters tested need to be reviewed. What is being presented - does not provide the whole picture.
I own those headphones and while I haven't listened to them in months, what I do recall is them lacking body. There was also a shrillness to the treble that made listening difficult with certain tracks. Swapping pads helped. I found Dekoni's hybrid pads retained the original voicing if you will, all the while adding body and smoothing the sound out. I'll have to break these headphones out when I get home later and have a refresher.

That said, there is nothing wrong with Amir's test methodology.

Also some measurements of the AKG K7XX and then Sennheiser HD650 for reference.
 

DonH56

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Back when I was a tech the blown output stages were no big deal to find and fix. One of the gnarliest issues was a leaky coupling capacitor that was enough to increase the distortion from something like 0.001% to 0.05% taking it above the 0.01% spec. I cursed that cap and when I finally found it pounded it into dust so it would never vex another. Then found out Denon wanted it for failure analysis before they'd pay for the warranty repair, oops... I gave them a bad cap, but it was not the bad cap (ssshhhh!)
 

restorer-john

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...Then found out Denon wanted it for failure analysis before they'd pay for the warranty repair...

They did that here too- they wanted the dead capacitors and other components back- even leaky electrolyte main filter caps. They'd invoice the replacements and credit them when they got the dead ones back. I think it was more to stop the techs stocking up on 'free' spare parts for paid jobs, by claiming they had to replace entire output stages etc.

Japanese high speed silicon was expensive back then.
 

Phronesis

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Personally, I’ve never relied on measurements to help me pick headphones. I think that listener ear geometry makes a significant difference, but that isn’t generally accounted for in measurements of FR curve, etc. I use reviews to help me identify candidates, then I try them myself.
 
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Headphonaholic

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Personally, I’ve never relied on measurements to help me pick headphones. I think that listener ear geometry makes a significant difference, but that isn’t generally accounted for in measurements of FR curve, etc. I use reviews to help me identify candidates, then I try them myself.
Measurements of headphones on their own aren't terribly helpful, it's when you use them to do comparisons that we get more useful findings from them. I've found that using measurements of headphones I like to compare against new headphones is a useful way of determine whether or not I will like them.
 

Phronesis

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Measurements of headphones on their own aren't terribly helpful, it's when you use them to do comparisons that we get more useful findings from them. I've found that using measurements of headphones I like to compare against new headphones is a useful way of determine whether or not I will like them.

I do see how that approach can work. I just take a different route because I find that, if I sort of average the opinions people give of a headphone, that will usually get me fairly close to what I'll perceive myself as far as tonality and other characteristics. Of course, there could be bias effect due to perceiving a certain way based on what others have said, but I see too much correlation to conclude that my perception is highly influenced by bias in that way.
 

Headphonaholic

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I do see how that approach can work. I just take a different route because I find that, if I sort of average the opinions people give of a headphone, that will usually get me fairly close to what I'll perceive myself as far as tonality and other characteristics. Of course, there could be bias effect due to perceiving a certain way based on what others have said, but I see too much correlation to conclude that my perception is highly influenced by bias in that way.
Ah yes, I do that as well. Which is why I recommend people to follow more than one headphone review source. It's good way to go about it but the frequency response measurements are just another tool to help validate it. This is especially important when purchasing expensive headphones.
 

DonH56

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But what about the alcohol? Can I still get that?

Sorry, but after this much time has passed I am quite sure The King has quaffed it all...
 
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