

Don’t be fooled. 24-bit will not fix computer audio - bensummers
http://gadgets.itwriting.com/?p=140

======
verisimilitude
Please don't focus on bits, when the [loudness wars][1] are the primary enemy
of quality sound _reproduction_ in most (not all) music recordings today.

This is about radio.

As you sit in your car, tune your radio to your local Top 40 station. You'll
notice that, even when you turn down the dial to the lowest audible setting,
you perceive a constant drone of music/noise (depending on how you feel about
pop music). Now, tune to the local classical station. Little spurts of noise
can be heard, punctuated by... quiet spots. The average consumer thinks:
"What's wrong with this music?! I have to turn up and turn down my volume all
the time!" Connoisseurs of classical music, however, encourage dealing with
this high dynamic range, because [dynamics][2] are a critical part of
classical music.

Here's the sad part: POP MUSIC DOESN'T NEED TO HAVE ITS DYNAMIC RANGE SMASHED!
Radio stations can easily take high dynamic range source material and run it
through a [compressor][3] to limit the dynamic range, thus making their music
more car compatible (solving the classical music 'problem'). However,
consumers expect to hear the same when they download an AAC/MP3 and play it
outside their car. "What's wrong with this old recording, it's so quiet", is a
common complaint. Of course, when iTunes (and competing software) have
features like automatic output leveling ([Sound Check][4]), compressing
dynamic range at OUTPUT and not at MASTERING should be the choice producers
make.

Yet, the industry persists, making the music louder at the expense of
eliminating its dynamic range. They're painting soundscape with a more limited
palette (though, doing a surprisingly effective job, given the limitations).

[1]: <http://en.wikipedia.org/wiki/Loudness_war> [2]:
<http://en.wikipedia.org/wiki/Dynamics_(music)> [3]:
<http://en.wikipedia.org/wiki/Dynamic_range_compression> [4]:
<http://support.apple.com/kb/HT2425>

~~~
headShrinker
As a former sound engineer, I agree with everything here. Just one correction
'sound check' doesn't add compression to a song but rather adjust (down) the
volume of songs that are perceived to be louder. This is referred to as
"normalization". Note: it does _not_ adjust (up) the songs that are perceived
quieter if they have peaks that are 100%... because they would clip. To get
them louder would require a process of limiting and compression.

------
vilhelm_s
When the CD was designed, 44kHz at 16bits was chosen because that exceeds the
limitations of human hearing.

With the introduction of Blue-Ray audio, there have been claims that the added
resolution makes it sound better. However, some members of the Boston Audio
Society did extensive testing where they compared (A/X/B) high-quality Blue-
Ray music versus the same music downsampled on the fly to 44kHz/16bit -- and
even after extensive listening on very expensive equipment by expert
listeners, it was impossible to tell the difference.

The results are reported in: E. Brad Meyer and David R. Moran, "Audibility of
a CD-Standard A/DA/A Loop Inserted into High-Resolution Audio Playback", JAES
Volume 55 Issue 9 pp. 775-779; September 2007.
(<http://www.aes.org/e-lib/browse.cfm?elib=14195> \-- I read a PDF last
summer, but now I can't find a non-paywalled version).

At the same time, there is widespread agreement that music released on Blu-Ray
Audio sounds better than CDs -- but this is not because of the extra bitrate,
it's because the sounds engineers pay more attention to details, and the discs
are marketed to Hi-Fi enthusiasts, so there is no pressure to e.g. destroy the
dynamic range by over-compressing the sound (which makes it sound
superficially better on low-end equipment).

~~~
rdale
"When the CD was designed, 44kHz at 16bits was chosen because that exceeds the
limitations of human hearing."

No it wasn't, it was designed to be implementable given the technology of the
time. Philips thought they were working on a 14 bit system, until Sony changed
the spec to be 16 bits. That wasn't because Sony changed their minds about
'the limits of human hearing', it was because they thought they could
implement the technology. 30 years later we can implement a bit depth of 24
bits with no problems.

According to the Wikipedia article on the history of the Compact Disc
(<http://en.wikipedia.org/wiki/Compact_Disc>) the sampling rate was defined
for the following reason:

"the exact sampling rate of 44.1 kHz was inherited from a method of converting
digital audio into an analog video signal for storage on U-matic video tape,
which was the most affordable way to transfer data from the recording studio
to the CD manufacturer at the time the CD specification was being developed."

So again this has absolutely nothing to do with 'the limits of human hearing'.

Recording engineers, such as Barry Diament of Soundkeeper Recordings, think
that the sound of 24/192 digital matches the output of the live microphone
input of their recording desk. Barry Diament doesn't think 16/44.1 is nearly
as good.

If you buy a recording at a high resolution you can always encode it as an MP3
or ACC so that it fits on your portable player. On the other hand if you buy
an MP3 or AAC recording you can't bring back the lost resolution. So if I can
fit my entire CD collection onto a cheap 1 TB hard drive, why do we care about
how much disk space high resolution 24/96 or 24/192 audio will take up? When
you don't have physical media it is trivial for a site to offer a range of
resolutions according to the needs of the buyer. If I want 24/96 and someone
else is only interested in 128 kps MP3s, then we can both download from the
same site and only pay for the quality we need.

~~~
ugh
If people can’t hear the difference in blind tests all that talk about the
supposedly better sound is utterly irrelevant.

~~~
rdale
Why would you value a 'blind test' over what an expert recording engineer,
such as Barry Diament, thinks?

There are a lot of problems with blind tests, and there has certainly been
much discussion about the arguments and counter arguments.

If you wheel in a bunch of untrained listeners off the street and get them to
listen to recordings they are not familiar with, using a Hi-Fi that they are
not familiar with, in stressful un-relaxed circumstances. Why would you expect
to get some kind of definitive answer about 16/44.1 vs 24/192 for instance,
that somehow trumps the opinion of highly regarded recording engineers?

~~~
ugh
Evidence trumps authority. I thought that was a basic lesson of science
education?

~~~
rdale
I thought I listed some of the possible flaws in blind tests - there is
nothing unscientific about that.

If you value the results of any sort of blind test, no matter how badly
conducted, over the opinions of recording engineers, then it doesn't seem to
be a purely scientific matter to me.

~~~
ugh
Your methodological criticisms are sound, it‘s just that they don’t seem to
apply to the quoted paper (I found the PDF):
<http://www.mesoscale.nl/aes_article.pdf>

~~~
rdale
OK, thanks I've read the paper.

If we are talking about whether 16 bits is sufficient dynamic range (the main
subject of this Hacker News discussion) they say:

"In one brief test with two subjects we added 14 dB of gain to the reference
level quoted and tested the two sources with no input signal, to see whether
the noise level of the CD audio channel would prove audible. Although one of
the subjects was uncertain of his ability to hear the noise, both achieved
results of 10/10 in detecting the CD loop. (We have not yet determined the
threshold of this effect. With gain of more than 14 dB above reference,
detection of the CD chain’s higher noise floor was easy, with no uncertainty.
Tests with other subjects bore this out.)"

To me, this confirms that a bit depth of 16 is insufficient for high dynamic
range music such as classical orchestral music. Maybe we don't need more than
20 bits (or about 16 bits plus 14 dB), but as we have the disk space, internet
bandwidth and electronics to comfortably handle 24 bits I don't see the
problem.

As far as sampling rate is concerned, they aren't comparing 24/192 PCM with
16/44.1 and so it isn't really relevant to a discussion about whether it is
possible to hear the difference between these two formats using a current
state of the art DAC.

I've no idea about the pros and cons of convertings SACD to 16/44.1 and doing
a comparison as I don't personally care about SACD and don't think it has a
future in downloadable non-physical formats.

They only talk vaguely about the actual equipment used which isn't normal for
a Hi-Fi review. They say they inserted a comparator:

"always in the 16/44.1 signal path. Audio switching was handled by an ABX CS-5
double-blind comparator"

Have they done a double blind test to ensure that the effects of the
comparator were inaudible?

They don't say what DAC or CD player they were using:

"For the CD loop we used a well-regarded professional CD recorder with real-
time monitoring."

I don't have enough to go on here. Certainly DAC and CD players have improved
a great deal in the last five years since these tests were made. From the
description I can't tell whether of not the CD player and its DAC were state
of the art five years ago.

So overall I agree the paper is an interesting read, but hardly the last word
in answering the question of whether we should move to 24 bit recordings, or
whether a sampling rate of 44.1 KHz is sufficient.

------
PBenz
Unless the dynamic range of the environment you're in is greater than the
difference of the dynamic range between 16 and 24-bit, and unless the audio
content also possesses that dynamic range, you will never hear the difference.

It's still useful to record at 24-bit, though, to give yourself the extra
headroom and avoid digital clipping. Recording at 24-bit is basically a no-
brainer.

Don't even get me started on recording using sampling rates higher than 44.1
kHz. This has been discussed ad-nausem on various audio forums.

Mix Magazine (I think) ran a double-blind test to see if people from all walks
of life, including experts in the audio industry, could hear the difference
between CDs and super-audio CDs. They could not. I believe we have indeed
reached the limits of human hearing.

~~~
samatman
The reason to record at sampling rates higher than 44.1 is to be able to pitch
and tempo shift with fewer annoying autotune-style artifacts. 2.8 MHz 1-bit
audio, clean, may not be distinguishable from 16/44, but add enough signal
processing and you'll be happy to have the extra bits around.

This is similar to the 8 bits-per-channel problem with GIMP. It's not that you
can see the difference; it's that when you factor in post-editing, it's nice
to have the extra bit depth.

~~~
ugh
I think no one doubts that higher bit depth and higher sampling rates are
useful when recording and editing, the interesting question is whether you can
get away with a lower bit rate and sampling rate when selling the music.

I would say that 16/44 is definitely enough if you don’t plan on editing the
music in any way.

What MP3 has shown is that size matters – even today. Flash memory is still
expensive, storage is still not unlimited, broadband access is still not
available everywhere. Why should we be needlessly wasteful in that last step
from producer to consumer?

(I’m a bit uncomfortable with that statement. Ideally, it would be possible
for us to just buy the raw, not yet re-coded output and a plethora of other
formats. Consumers can then just re-encode themselves as needed. 24/96 truly
is better – humans can’t hear the difference but if our ears were better we
would – there is really no harm done in selling it. But any claims that
consumers really need 24/96 audio seem simply wrong to me.)

~~~
bad_user
And what happens when music goes into public domain and you want to remix /
enhance that music?

That's why I still prefer to buy audio-CDs: I turn songs into ringtones all
the time. To create a good ringtone, you have to cut, normalize the amplitude
/ compress the dynamic range (to avoid clipping) and then increase the volume.
And then compress as MP3.

Doing that on an MP3 that's already low-quality, uploading to a phone with an
obviously subpar loudspeaker, produces awful results.

And disregarding the people that would go through pain for doing the above,
there is still a market out there for people wanting to get the best sound
possible, even if they couldn't tell the difference.

~~~
ugh
I don’t want to do that.

------
ajg1977
Really, all this talk of introducing "higher quality" digital music is the
record companies looking for the next way to keep you paying for content you
already own.

I can even understand their fear. Until now every format has had a mass market
lifespan of ~15-20 years. When people switched, huge numbers of 'library'
albums would be sold providing a nice amount of income for very little work.

It's hard to imagine people ever paying to replace existing mp3/aac tracks,
and worse - you and I can give each of our children a perfectly reproduced
copy of our entire music library.

------
gallerytungsten
When getting into these discussions of bit depth and sampling rate, the debate
is endless among audio engineers about the differences. What really makes a
difference is the specific gear you use (mics, preamps, processors, a/d
converters, clocks, etc.).

Debating the numbers without discussing the signal chain is somewhat
ridiculous. A fantastic (great gear) 16/44 chain will sound a lot better than
a crappy 24/192 chain. The concept of a signal chain "only being as strong as
the weakest link" is of great importance.

That is only the tracking side of the equation. Eventually, individual tracks
get mixed down. Your summing bus is the flip side, and there is a lengthy
debate over mixing in the box (digital summing) vs. analog summing, which can
be done with a traditional mixing console, or with the recently invented
category of gear known as "summing boxes." (There are of course many further
variations and permutations.)

On top of that, the skill of the engineer will also make a large difference.
Those interested in the details may wish to visit a site such as gearslutz.com
where these topics are discussed and debated in great detail.

~~~
juiceandjuice
Gearslutz is okay, but the topics are for more amateur IMO. I think best
sites/forums to talk about recording audio are the tapeop forums and
electrical audio tech forum. You must be warned though, they (generally) have
an "analog is better but I embrace digital" mindset.

<http://messageboard.tapeop.com/>

<http://www.electrical.com/phpBB3/viewforum.php?f=5> (You can argue with Steve
Albini on here :)

------
Derbasti
Recently, Apple started talking about 24 bit. Now HP/Dr. Dre is talking about
24 bit. It makes a good story. But fact is, most audio bought online is in
some compressed format (mp3,mp4/m4a/aac). Digital audio compression works by
reducing the bitrate of certain parts of the music (frequency-time blocks). So
24 bit is nice but audio compression reduces it anyway.

So, this is apparently not about compressed music then? It must be about
uncompressed music. Well, we can't change the redbook CD standard. I guess
these people must be talking about DVD-As and SACDs then? They clearly are
not.

Now there is one thing that I would actually love to see (but that these
people do not seem to be talking about). I would love to buy 24 bit 96 kHz
FLAC-encoded music on iTunes. Or maybe not FLAC but Apple Lossless or whatever
and maybe not iTunes but Amazon or some new HP thing. I don't care. But
Lossless, High-Quality Music in some major online music store. Now that would
be something!

~~~
headShrinker
Each song would be about 150MB at 96/24.

~~~
bdb
That's fine. Apple "sells" HD movie rentals (~3 GB) which are only useful for
24 hours.

~~~
headShrinker
Good point but I am also concerned about how many songs I can fit on my
player. if each song is 150MB, I could fit 30 times less songs. I want higher
quality audio if anyone does. My ears are trained and have spent 10 years
mixing behind near-field monitors. I have done side by side comparisons with
50MB 44/16 audio and 5MB 256kbps AAC encode, and I can't hear the difference.

------
EgeBamyasi
"The speakers built into a portable computer are most likely a bit hopeless –
and it may well be that HPs are better than most – but that is easily overcome
by plugging in powered speakers, or using an external digital to analog
converter (DAC)"

I bought a low end recording audio interface( E-MU Tracker Pre) whitch
features a pretty decent DAC and boy oh boy does it make the music pop!

Comparing a 192kbps MP3 featuring a big dynamic range with headphones
connected directly to the on board audio on my laptop vs headphones connected
to my Tracker Pre there is a night and day difference. On the external sound
card the MP3 still sounds a little flat, but it does it with class as opposed
to boring on the onboard DAC.

So before you get into the whole "OH LAWL, MUST ONLY LISTEN TO FLAC" thing
start by updating your sound card, its well worth the money!

~~~
juiceandjuice
Actually, a lot of laptops have decent DACs. My thinkpad has an AD1984:

[http://www.analog.com/static/imported-
files/data_sheets/AD19...](http://www.analog.com/static/imported-
files/data_sheets/AD1984.pdf)

With a SNR of 96dB, you should be able to get all your resolution out of
anything originating from a CD.

HOWEVER, Sometimes recording equipment drives inputs much better than cheaper
chips, so you get that difference in sound quality.

I have some Audio Technica ATH-M40fs headphones that prefer pro stuff because
of their 60 ohm impedance, but even on a laptop they sound great (Which for me
means flat) [http://www.audio-
technica.com/cms/headphones/7c784888146c212...](http://www.audio-
technica.com/cms/headphones/7c784888146c212e/index.html/)

They also handle up to 1.6W power (8 times that of an AKG k240 :)

~~~
EgeBamyasi
I have still to come across a laptop which does any music justice. Ive mostly
been using HP and Dell, will have to look at a thinkpad next time :-)

Ive listened to those powerd by a CMOY, great bang for the buck. What amp do
you pair them up with?

------
harshpotatoes
So there is this recent talk about sound quality from computers, and it makes
sense to me that dynamic range would be the biggest culprit against good sound
quality. However, every now and then I still here people chime in that
upgrading your sound card will also increase your sound quality. Being
curious, I went in search of sound card reviews. Of the reviews that I can
find, and which aren't ten years old, I can only find reviews of the high end
cards which obviously come to the conclusion that the high end cards produce
high quality sound. Of course, the numbers they show are quite meaningless,
because I have nothing to compare them too. Are there reviews of onboard audio
anymore? I have a feeling that technology has progressed to the point that all
onboard audio is good enough assuming you have decent speakers/headphones, but
does anybody else know?

~~~
jmillikin
Sound cards were important a decade ago, when CPUs were not yet capable of
rendering complex audio. If you wanted to (for example) remix ten mono
channels to 5.1 surround in real time, the only option was a separate
dedicated processor.

Since then, CPUs have become massively more capable; any reasonable audio
processing can be done on a budget desktop. The only real reason to get a
separate sound card any more is specialized connectors, but even that's
becoming less true -- even my normal, non-fancy motherboard has an actual
S/PDIF jack!

Of course, even if a third-party chip's output was not measurably different
from an integrated chip, there would still be hordes of idiot audiophiles
rushing to drop a few grand on one.

~~~
chipsy
I agree, roughly. At the audiophile level there is some improvement to be
expected with S/PDIF in particular(less cable noise). But the situation today
is nothing like with older on-board sound where they used the cheapest generic
AC97 chips and the output sounded like a tin can.

If you're recording or need low latency playback, there's still tons of room
for improvement by getting a sound card. For good recordings, you need a
preamp stage, you need <50ms latency, and you (often) need more than one
track. And the entry price for these features is still relatively high,
between $100 and $250.

------
zandorg
I master my songs to 24-bit 192khz - a single master and every multitracked
track. Even with 20 tracks at that resolution, each song fits on a DVD-R.

As to why I need that resolution, my ancient analogue synth can sound good at
that high resolution.

As for distribution, I just post FLAC files to my website.

~~~
mambodog
_24-bit 192khz_

No-one will tell the difference between that and Redbook CD quality in a
double blind test. For recording, and intermediary files, sure, knock yourself
out. For the final master 16/44.1 is plenty.

~~~
justincormack
Yes, as the article points out, if you don't go mad and apply far too much
compression like so much recorded music does. Over compression is hideous...

~~~
zandorg
I compress individual drum/synth tracks through 'insert' channels. All my
mixing is done in the analogue world, and only finally goes into my Emu 0202.
I used to compress finished tracks, but I have the attitude that people can
apply their own compression. But me compressing individual tracks is fine.

------
mwsherman
Indeed, bit depth is hardly the problem. Uncompressed 16/44 sounds really
good, and they can offer that now.

The problems are compression and end-user audio equipment. (And they are only
problems if the consumer cares.) If the industry wants to tangibly move
quality forward, they should simply up the standard bitrate to 320 or beyond,
today.

~~~
dedward
I can agree - hearing a well mastered CD on some decent (not super high end,
just good) amp and speakers, in a quiet environment, shows there is plenty of
detail and dynamic range. My nice amp and headphones show me that even
decently encoded MP3s are often limited by things further down the playback
chain (dac/amp/speakers/headphones) than the audio format itself.

------
atlei
Anyone have any tips/links to convert my CD's into great quality MP3's (for
listening only) ? I've been using VBR, 196, Lame etc, but this was recommended
to me years ago...

Which encoder/tool/settings do you recommend for Windows (and Mac) ?

~~~
kronusaturn
lame --preset extreme

------
ugh
We have reached the limits of human hearing, to believe that tweaking the
sampling rate or bit depth will improve audio quality is foolish. We should
use the 16 bit we have better – that’s the real problem. 24 bit won’t help
with that.

~~~
Bud
We did reach the limits, or nearly, but then we backed way off from the
limits, and stayed back. 128kbps MP3 is most certainly NOT reaching the limits
of human hearing, for instance.

So to the extent that a push for 24-bit files will result in higher sampling
rates in the kinds of files most folks are listening to, yeah, it could be a
big help. Especially if you are talking about my field, classical music, where
the dynamic range involved is much wider and the variety of sounds involved is
much greater.

Will it be the 24-bitness that causes the improvement? Not directly, no.

~~~
ugh
I was talking about 16 bit, 44.1 kHz, not 128 kbps MP3 [0]. Oh, and the
sampling rate has nothing to do with the bit depth. 44 kHz gives you
frequencies up to 22 kHz, that’s at least two kHz better than great human
hearing. I don’t see any possible reason why a higher sampling rate would be
necessary.

I also would like to know what you mean by 24 bit causing an improvement
indirectly. How so?

[0] I attended a university lecture with one of its main inventors and he told
us in no uncertain terms that 128 kbps MP3 is definitely not CD quality and
also that MP3 has certain artifacts (castagnettes are its enemy) that cannot
be remedied by simply picking a higher bit rate. Lossy audio compression is
still extremely clever and cool.

~~~
Bud
Yeah, but my point was, most of us are no longer listening to 16/44.1 CDs.
We're listening to MP3, AAC, etc. If we were still listening to CDs directly,
there wouldn't be an issue.

What I mean by the push for 24-bit causing an improvement indirectly is, Apple
(and others) aren't stupid. They aren't going to just up the size of the
sample to 24 bits and leave the sampling rate and overall quality alone.
They're doing this to offer much larger files, probably 24/96 files, with
either lossless compression or much less lossy compression, so they can a)
sell those files for more money and b) justify folks purchasing new audio
players and huge amounts of storage to store all their new shiny files. My
point is therefore that 24-bit will drive an overall improvement in quality,
hopefully to something greater than CD quality.

~~~
ugh
Ah, ok, that’s understandable. I would, however, be much happier about
lossless music that doesn’t needlessly waste storage space. Mobile storage
space is still limited, especially after everyone switched to flash memory.

(I’m personally happily buying 256 kbps AAC files. I did a blind test before I
started investing money and couldn’t hear the difference. Buying and storing
lossless files would be kind of pointless for me personally.)

------
dfox
It may be interesting to note that probably any computer manufactured in last
five years is perfectly capable of playing 24bit PCM at ridiculous sample
rates (like 192kHz) as even low-end audio codec chips for Intel HDA support
that.

------
goalieca
Computer audio is broken? News to me. I'm happy with the 44.1Khz @ 16-bit.

------
rythie
Does anyone distribute 24bit content anyway? iTunes, Amazon, Spotify etc. I
don't think any of them do.

~~~
Bud
Not yet. That's the idea; they will begin to. Apple is apparently already
talking about doing so.

[http://www.macrumors.com/2011/02/22/apple-reportedly-
looking...](http://www.macrumors.com/2011/02/22/apple-reportedly-looking-to-
offer-24-bit-music-files-in-itunes-store/)

<http://venturebeat.com/2011/02/22/apple-24-bit-music/>

[http://articles.cnn.com/2011-02-22/tech/24.bit.music_1_highe...](http://articles.cnn.com/2011-02-22/tech/24.bit.music_1_higher-
quality-music-online-music-stores-music-catalog?_s=PM:TECH)

~~~
rythie
Interesting, the hype around 24bit could kill off the CD, since CDs can't
really compete with that and DVD-Audio and SACD failed to reach the mass
market.

As a bonus to Apple they will take more space, especially if they use FLAC, so
people will buy bigger iPods and iPhones.

~~~
wladimir
SACD failed to reach the mass market, partly, because most music customers
didn't really care about 24 bit audio. At least, not enough to pay more for
it. I don't think it's different this time.

Music quality is not an issue for most people. If it was, low-quality mp3 and
players with crappy headphones, and crappy computer speakers wouldn't be that
popular.

~~~
Bud
But people with lots of money find it to be an issue. Or, they at least
pretend to. And they will pay for the right to pretend to. :) And once the
rich do so, we have a long tradition in our society of imitating the
consumption habits of the rich.

------
jfm3
"Jimmy Iovine Does Not Understand Math."

Fixed that title for you.

------
georgieporgie
Never take audio quality advice from someone who sells through Best Buy.

