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What am I hearing: source or playback distortion?

Momotaro

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Forgive the open-ended thread title. It seems better to ask via a new thread instead of de-railing recent existing threads I've seen. I'm hoping that people with studio recording experience, and/or people with different playback equipment may shed some light.

When listening to recordings, especially those with reasonably well-isolated vocals—and especially female—I seem to hear a haze (for want of a better descriptor). It's higher in frequency, and appears to closely follow the envelope of the vocalisation. It also sounds slightly un-natural (again, for want of a better descriptor). Oversimplifying, imagine the vocals as a pure sine tone varying in pitch, and the 'haze' as a lower-amplitude square wave modulated by the original tone's frequency and attack-decay envelope. Of course, vocals have harmonic timbre, I'm simply illustrating the overall perception via an analogy.

My front-running guess is that it's an artefact of recording: microphone behaviour, processing via many effects devices and amp stages, a by-product of deliberate production effects, that sort of thing. Another possibility is that it's harmonic distortion in my playback equipment. Or peculiarities in my hearing. Or a combination. Or something else?

To rule a few things out, I've listened to the same tracks streamed via compressed and uncompressed "lossless" formats. And via speakers and some different headphones. The 'haze' is exaggerated by some Sonys (MDR-Z1X with infamous voicing) which is a logical product of frequency response compared the Sennys (HD600) but 'haze' is never absent. The headphone chain is Mac>USB to Mojo DAC>analog out, or Mac/iPhone>Bluetooth to AirPods Pro. I don't have the very low distortion AirPods Max to try. The speaker chain is Mac>USB to DAC>XLR to class AB amp>speakers. I don't have a super-low-distortion amp like a Purifi, but as the headphone chain doesn't eliminate the issue, I suspect it isn't the amp. Purifi was one solution I was originally considering. Likewise, toggling full-range room correction and various filter options (liner phase/mixed/zero latency) don't appear to be critical variables.

To try this at home, I've used tracks from London Grammar in particular. They use a bit of reverb etc so I also subjected myself to Diana Krall on the off-chance that audiophile-grade sonic purity would help. It didn't. Left-field possibilities I haven't ruled out include an all-analog signal chain (assuming suitable source recording) which I don't have on hand to try.

For context, I'm not at all averse to deliberate distortion as an aesthetic choice. I'm also fond of shoegaze. That said, if anyone can suggest a purist recording for comparison, I'm interested. Anyway, enough rambling: do other people hear this? If so, do you obviate/mitigate it? I'd appreciate anyone's cogent thoughts.

edit: added specificity to thread title
 
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DimitryZ

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Playback. There isn't any haze in Krall's recordings. I would check your Bluetooth connection quality.
 
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Momotaro

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Playback. There isn't any haze in Krall's recordings. I would check your Bluetooth connection quality.
Nothing amiss in the settings I can see. Only one of the four playback options was Bluetooth (wireless to AirPods Pro from Apple Music which I think means AAC, everything else at minimum 16/44.1 "lossless" and "Apple digital master" fwiw). I can hear it on Krall's recent album This Dream of You, for example.

For additional context, the effect is fairly subtle, and far from overwhelming. I notice it more on sparse recordings, of course, hence the examples. Assuming HD600s run around 0.1% harmonic distortion in the vocal range (and ignoring harmonic profile of same for simplicity) maybe that's just what that level of distortion sounds like? I'm surprised I can hear that tbh. There's no blind test on audio check.net but sighted I'd put my threshold no better than .05% on 250/500 Hz tones using the Sonys, which may exaggerate the relevant harmonic frequencies (take sighted evaluation with a grain of salt, obviously). So the vocal effect must be a bit stronger than that. All that assuming it's not the recording.
 
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DimitryZ

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Perhaps try high quality wired headphones? You really shouldn't be hearing audible distortion.
 
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Momotaro

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Re distortion, that's what I would think, maybe I'm sensitive it in that frequency range (and for certain types of music)? Any particular headphone suggestions?
 

DimitryZ

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Sennheiser with a decent amp should be distortion-free.

It's unlikely you are different from other humans.

We're you in the military and exposed to high volume sounds, like artillery/tank gun fire?

And if you were, thank you for your service.
 
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Momotaro

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HD600 was one of my test headphones.

I don't expect my hearing is special in the overall sense. People do report different subjective sensitivity to treble, so I considered that. Different ear shapes, perhaps. No military service or obvious hearing damage.

I'm wondering if it's just what vocals recorded with microphones generally sound like and I'm just noticing discrete sonic characteristics more as my gear and listening experience gets better?
 
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Momotaro

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So far one vote for playback, one for source and one for investigate. Pretty much where my head was at. Thanks for your thoughts, appreciated.
 

kongwee

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Remove unused equipment(even it is power off) and move my SSD drive away from my audio interface reduce 50 hz hum and very high frequency noise. Playback is more clearer.
 
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