
Effects of MP3 Compression on Perceived Emotional Characteristics in Music - pbowyer
http://www.aes.org/e-lib/browse.cfm?elib=18523
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wbkang
Before anyone jumps to conclusions, the paper is comparing the original audio
with MP3s compressed at 112kbps and under, where the compression artifacts are
very easy to notice.

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leeoniya
was about to say this.

192Kbps VBR is the minimumn for transparency for me. i've been moving my whole
collection FLAC -> Opus 160Kbps VBR (which is widely regarded as audiophile-
transparent).

~~~
seanp2k2
Same. It's crazy to me that people are saying that they can hear the
difference between 24-bit 192khz recordings and something like 320Kbps MP3 or
192 VBR (which is what most of my personal collection is at). Back in the day
on [huge;y famous private torrent tracker], FLAC and 192k VBR were the gold
standards, with most opting for the VBR version. I personally have some VERY
nice headphones, speakers, and sources (Senn HD800s, Westone ES60, KEF LS50,
RME ADI-2 Pro, etc), and I can't hear the difference between this high-bitrate
stuff and the lower encodes. I CAN hear a HUGE difference between bad
recordings and good, but that doesn't stop me from enjoying my favorite
albums. I have other headphones, speakers, IEMs, and sources for different
needs, for example working out...I like my Jaybird Tarah Pros, and even though
they're not "audiophile", I've still had tons of enjoyment with them doing
things like skateboarding, mountain biking, and riding my motorcycle. Horses
for courses. The HD800s is NOT great for bass-heavy music, so in that case,
I'll switch to a Shure 1540 or Beyer DT1770, which even though they're more in
the higher-end mid-fi range, have each brought me many hours of pleasure over
the years.

This is a fun hobby, but it's possible to make it less fun by arguing on the
internet with people about it. If it sounds good TO YOU, and it's worth the
price TO YOU, then never let someone make you feel bad about it. Some people
buy $10k cables (or "worse" imo, cable elevators [e.g.
[https://forum.audiogon.com/discussions/the-finest-cable-
elev...](https://forum.audiogon.com/discussions/the-finest-cable-elevators-
you-ever-auditioned) ]. I think that those are ridiculous, but some people
swear by them, and that's their choice. I'm the guy with the inner tube under
the turntable playing with air pressure, because I love a good hack and have a
penchant for DIY. I've built speakers that sound bad, but I've always learned
something from every build. If you want TRUE REFERENCE sound, look up exactly
what gear your favorite recording studio uses, and buy the same set-up.
Otherwise, just have fun :)

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rorykoehler
I can hear the difference between them but honestly I listen to Spotify on
highest quality setting (320Kbps I think?) for my everyday because it's
convenient and already sounds great. I'm listening in an imperfect environment
anyways with environmental noise from outside and a non-treated room. My main
benchmark is does the codec give me listening fatigue which, for example,
Soundcloud and 128Kbps does but 320Kbps doesn't.

As an aside people who swear by 24-bit audio don't even understand what bit
rate does in context of audio. It's only useful in the studio context.

Edit: Not sure why I'm getting down voted. I can explain the difference as
added sparkle in the transient high end frequencies. My hypothesis is that the
presence of frequencies outside of the range of our ears affect the
frequencies within our hearing range. It's pretty common to have to re-EQ the
whole track after EQing one instrument in a mix so this concept is just being
applied outside our hearing frequency spectrum Also I would like to point out
that higher bandwidth audio doesn't necessarily sound better to me, just
different.

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cjhanks
I upvoted you, but you're wrong. 24bit audio depth matters, especially in jazz
and classical recordings. You notice both subharmonics and superharmonics
missing. Particularly when their phase is slow in time.

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rorykoehler
Case in point. The bit rate has to do with dynamic range not frequencies.

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cjhanks
The reverberation of a single tone can be _in phase_ or _out of phase_. The
results is observed as a beat frequency in amplitude.. not in tonal frequency,
that's what why bitrate matters.

~~~
rorykoehler
We use higher bitrates during recording to lower the noise floor, in turn
giving more headroom in the mix. Once you mix down this becomes irrelevant
because the difference between silent and full volume at 16bit is enough to
cover the full capability in terms of sound pressure levels of the human ear.
1bit = 6dB which means 16bit is 96dB. As we don't start at absolute zero but
with a background noise of the room at 30dB using the full dynamic range of
16bit at playback you risk deafening yourself.

In your example if your single tone is out of phase then 1) how do you control
this at any bit rate and 2) this is controlled by an acoustically treated room
and a skilled engineer during recording. When you listen on headphones you
already eliminate this concern on playback and unless you are listening in a
professional designed and treated listening studio you will always have some
element of phase cancellation. This is the listening character of your room
and will occur at any bitrate.

Read this [https://www.mojo-audio.com/blog/the-24bit-
delusion/](https://www.mojo-audio.com/blog/the-24bit-delusion/)

~~~
cjhanks
You know - I agree with this article. Thank you for your thoughtful response.

I understand and agree that 24bits is enough for human perception. But
something else is happening in MP3 encoding. Some sort of assumptions about
human perception of dynamic range that are inaccurate. I am not expert enough
to know precisely where. But I generally understand compression and I am an
"audiophile".

Nothing in the article stands out as false to me. But I cannot help but
believe it might be missing something.

------
S_A_P
Maybe slightly off topic but I would be curious to know what the artifact of
lower bit rate mp3 encoding is actually doing. It’s not aliasing, but it’s in
the 6-15khz range. I could only describe the sound of the artifacts as a flock
of seagulls in the distance flying towards you.

Edit: found this which answers a lot of this.

[https://www.soundonsound.com/techniques/what-data-
compressio...](https://www.soundonsound.com/techniques/what-data-compression-
does-your-music)

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userbinator
Relatedly, this article nearly a decade(!) ago mentioned that younger people
of the time were preferring the sound of MP3 compression artifacts over
higher-quality compression or even the original uncompressed audio:

[http://radar.oreilly.com/2009/03/the-sizzling-sound-of-
music...](http://radar.oreilly.com/2009/03/the-sizzling-sound-of-music.html)

I suppose it's similar to how some people prefer the distortion of "tube
sound".

~~~
bni
Im sceptic of this slashdot classic. Was this ever verified independently?

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vkaku
As of today, if I need to compress, I use M4A/ALAC. This article may have been
appropriate >10 years ago.

Most of the time I have good speakers and decently encoded sound, I do not
have any real quibs.

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out_of_protocol
Check out opus encoding - should be way better

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pizza234
The available research is incomplete.

The Opus "Comparison" cherry-picks the sub-128 kbps bitrates, where the format
is evidently strong, but it doesn't include references for high-bitrate music
compression.

Actually, even their (partial) diagram hints that there is virtually no
difference at over-160 kpbs bitrates.

I'm struggling to find high-bitrate music compression (blind) listening tests
lately in general; it seems that the internet crowd enthusiasm in the subject
vanished in the last decade.

~~~
ZoomZoomZoom
What do you mean by incomplete? What information do you lack? If you meant
some tests of OPUS over 128kbps, then it's just there's no real need for it.
Why would anyone want to add some 50-100% weight to your files for almost no
audible increase in quality? In any case, lossy codecs are not meant for
storage/critical listening.

Lack of enthusiasm in publishing tests can probably be explained by the ease
of performing ABX tests by yourself with your own gear and exact listening
conditions you're aiming for.

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yrf
>Compression _effected_ some instruments more and others less

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stephen_g
Affected [1] is correct. You could perhaps say 'Applying compression effected
an undesirable change in some instruments...' \- the sound of the instruments
is affected by the compression, but the _change in the sound_ has been
effected by the addition of compression.

1\.
[https://en.oxforddictionaries.com/definition/affected](https://en.oxforddictionaries.com/definition/affected)

