In article , joe
wrote:

D. Peter Maus wrote:

On 07/02/09 15:48, Brenda Ann wrote:

2) There is NO mp3 player that can as accurately reproduce a complex
audio
waveform as well as a high end cassette machine. I don't care how many
samples you take of a complex waveform with an ADC/DAC system, the
resultant playback waveform will never represent the original analog
waveform as well as a high end analog device. Even a simple 1000 Hz sine
wave will not come out as a pure sine wave after digital conversion, it
will be a series of stepped square waves. You may not be able to tell the
difference with your ear, as long as there are enough of those little
steps, but that's not the point. The point is, it will not "run circles
around" a high end analog device.





If you take a look at a 1khz square wave after digital
conversion, you'll see ringing at both ends of the flat top. You'll
see that same ringing wherever there is a hard rise or fall. Is it
audible? Oh yeah. More so on a naked square wave. Less so in complex
music. But you can hear it.

You'll see this wherever there is hard digital filtering, such as
anti-aliasing on CD players. You'll see it where there is copious
amount of data loss, as in MP3.

An MP3, at it's best is a 4:1 data loss. The songs on iTunes and
elsewhere are mostly 10:1 data loss. Sometimes more, sometimes less.


Isn't equating compression ration or data rates to data loss a bit
misleading? Sure, MP3 and AAC are lossy codecs, but a lossless codec such
as FLAC reduces the data rate without loss of the original content. The
amount of original signal lost by the use of AAC or MP3 compression is much
less than you imply with your numbers.

Noise may be reduced, but it's hardly high fidelity audio. And
though cassettes have their many flaws, a properly set up Nak will
have more noise, but far less digital artifacting and zero data loss
than any MP3.

I would expect an analog system to have no digital artifacts. But, you admit
there is more noise, isn't that also a loss of 'data'. But you also ignore
any reduction in bandwidth that occurs with magnetic recording. Also, at
its best the Nak may have higher distortion than a high end MP3 player.

Cassette decks have their BW specified at -20 db because at higher levels,
head/media saturation limit useful bandwidth.

There are several technical criteria that must be met with digital
recording so that it can equal analog. These criteria must be met in
both directions, analog to digital, and then digital back to analog
being a complete process.

The sampling rate must be twice the highest frequency you want to record
so if the analog frequency is 22 KHz then the minimum sample rate is 44
KHz. A higher sample rate is better. For this sampling scheme to work
well the conversion in either direction should be low pass filtered.
This scheme has the 22 KHz sine wave represented by two steps, which is
very coarse.

The analog filtering will help the reproduced analog look like the
original recorded analog signal but the conversion sampling has several
types of imprecision to contend with besides sample rate. Just as
important are sample levels. The smaller the sample level the more
precise the reproduced analog will be.

So the two main parameters are the number of samples made in time and
voltage or to look on a sine wave on a graph the horizontal and vertical
axis. The smaller the steps in either axis the closer the digital
stepped waveform approximate the analog. Then a low pass filter smoothes
out the tiny steps as a way of "polishing" the digital waveform to look
even more like the analog.

The problem with the above conversion scheme is the sample imprecision
in time and voltage, which leads to conversion noise and distortion. The
precision can be improved with an increased number of steps in either
axis. Increasing the number of voltage steps means the sampling number
must be numerically larger and increasing the sampling rate increases
the number of samples that must be processed and stored for the same
length of the recording so higher quality means bigger numbers and more
of them.

This is a big problem for digital recording, storage, and reproduction.
If you want high quality you need the electronics to operate rapidly and
generate more data requiring larger storage. The electronics operating
rapidly consumes power and large data storage also costs more money so
the solution is low sample rates and small sample numbers.

Along with small sample numbers and low sample rates, data storage
requirements are further reduced with compression algorithms that are
lossy or in other words further distort the data. Here "lossy" means
some of the data is thrown out and not saved to storage.

The financial cost of these problems also burdens the transmission of
digital data similar for the digital storage cost. Higher quality means
higher transmission rates similar to larger storage requirements. Higher
transmission rates means the signal must occupy more spectrum. For this
reason and others the IBOC and DRM sounding "better" in the same band
space is just plain BS.

So basically, regardless of the sample size and rate used you have
inherent sampling and anti-alias filtering distortion so the converted
analog waveform can never be as good as the original but using more
power, band space, and storage it can be close.

We are all used to the continual improvement in electronics where they
run faster with less power and storage becoming cheaper, smaller, and
lighter with time, so with time all this can be overcome except the
amount of band space needed for transmission. Here improvements in
electronics cannot overcome basic physics.

--
Telamon
Ventura, California

In article 4a4e64c4.303406@chupacabra,
Bob Dobbs wrote:

Telamon wrote:

The universe is analog not digital so you get over it.

The universe IS digital so you get used to it.

That your personal biochemistry can't resolve the refresh rate only
tends to mislead you into thinking it's analog. IOW: If you drive
fast enough on a washboard road the bumps will only seem to go away
as your suspension does its thing.

Quantum physics stating the universe is digital is an
oversimplification at best and I'm being very generous.

You need to be more generous to yourself and not be so quick to
dismiss things that overwhelm your intellect.

You are clearly the one overwhelmed. We don't operate at the quantum
level and neither do objects larger than the chained molecular level
that we interact with so don't be so stupid to conjecture that because
the science of fundamental matter has quanta energy levels that is the
way macro physics world operates because it doesn't.

--
Telamon
Ventura, California

In article 4a4e64c4.303406@chupacabra,
Bob Dobbs wrote:

Telamon wrote:

The universe is analog not digital so you get over it.

The universe IS digital so you get used to it.

That your personal biochemistry can't resolve the refresh rate only
tends to mislead you into thinking it's analog. IOW: If you drive
fast enough on a washboard road the bumps will only seem to go away
as your suspension does its thing.

Quantum physics stating the universe is digital is an
oversimplification at best and I'm being very generous.

You need to be more generous to yourself and not be so quick to
dismiss things that overwhelm your intellect.

This is a good analogy to your missive.

http://news.yahoo.com/comics/uclickc...l_uc/crbal2009
0702

"Some parts of Carl's thinking think other parts are pretty nuts."
"You gotta be kiddin' "

--
Telamon
Ventura, California

On Jul 3, 10:08*am, dave wrote:

IN THE BRAIN the ELECTRICAL IMPULSES are translated into SOUNDS which we
recognize and understand.


Your nutsack hasn't understood anything since your accident.

Sound that is too LOUD will blow off some of those tiny little hairs in
the Ear canal.That impairs hearing too.

Eh, what did you say? I can't hear you!

Clean that nasty old wax out of your ears and you might hear
something,,,, and stop pickin them boogers out of your nose!

Eh, hold out your cup and catch this booger.
///KLINK///
cuhulin

On Jul 2, 5:44*am, dave wrote:
LukeP wrote:
On Jul 1, 3:57 pm, Barry wrote:
http://www.sfgate.com/cgi-bin/articl...7/01/BU2618GKE....

What's an iPod?

I read the article also. *Most people look at the cassette as
equivalent withthe *8-track tape. *But I bet these same people would
be shocked to find out that some of the better cassette decks had way
better specs than a Ipod. *I have seen some of the Naks with freq.
response to 27 khz and my Denon, which was a mid-level deck, has freq.
response to 23 or 24 which I know is more than you can squeeze from
digital at even the highest bit rate. *I'm just sayin'..........

Sad. *You can't hear much above 10 K; *why do you care about 24?

You can buy a credible MP3 player for $20 that'll run circles around
your POS Nakamichi.

Reality check!

I have yet to respond to any post on this group in over a year, but
after 34 years in high end audio (sales, technical sales training,
product planning and development on three continents...) I couldn't
resist...

Frequency range has very little to do with it. ANYTHING that
compresses by any form of digital "bit grooming" can loose vital
information. Case in point... A fairly high priced MP3 recorder/
player with minidisc and computer MP3 capabilities managed to lose the
bells (actually a glockenspiel, I believe) at the beginning of a
Phoebe Snow track that I used as a demo for years (many other
examples, but this is a case in point). Digital compression can lose
textures, details, imaging, transient information in ways that is
COMPLETELY foreign to the human psycho-acoustic mechanism. Our ears
and brain can "fill in" information lost by anything as natural and
simple as bandwidth limiting, BECAUSE IT HAPPENS IN NATURE ALL THE
TIME! If we, as a species, have had to deal with bandwidth limiting
by something as simple as distance or intervening materials such as a
drape or some walls, etc., WE HAVE ACHIEVED THE ABILITY TO RECONSTRUCT
THE MISSING HARMONIC INFORMATION. And we can pull information out of
the noise floor of analog recordings by dithering.

I used one of the few decks that can trump all of those mentioned
above (although the Nakamichi units were excellent), the Tandberg
3014A, and have been able to produce recordings that (on over
$60,000.00 of amps and speakers) rivaled the very best digital
technology available at the time (2005 or so), and was only lacking
compared to an excellent virgin vinyl LP on $10,000 worth of
turntable.

As for bandwidth and digital technology... Anything that has a bit
rate as high as SACD or Meridian lossless packing on DVD Audio can
produce a bandwidth of 50 kHz and beyond. And that is your best hope
of achieving a recording that can compete with high end analog,
PERIOD! I have some SACD remasters of mid-1960 Rolling Stones
recordings that sound BETTER than the British virgin vinyl recordings
of the exact same performances. Of course, digital is quieter, but
I've already mentioned that we can dither significant information that
is below the noise floor in an analog recording. The "noise floor" in
a digital recording is the point of no return. NOTHING exists there,
it's all truncated. Ignored!

I know of NO MP3 device that can compete with the best Tandberg,
Nakamichi, Harman Kardon 400 series CD recorder regardless of the bit
rate. THEY DO NOT EXIST!

And a truly audiophile turntable with a moving coil cartridge can
trump any of the above in most respects, but that's another
subject...

On Jul 3, 10:09*pm, guyo wrote:

And a truly audiophile turntable with a moving coil cartridge can
trump any of the above in most respects, but that's another
subject...

Maybe so but the price is prohibitive except for the elite
billionaire.

For far, far less dinero a very decent SA-CD player, a modest 5.1
channel surround sound amplifier, and 5 mid-priced full range speakers
and subwoofer will equal the best mucho dinero mega-bucks elite vinyl
sound system TO THE VAST MAJORITY of listeners.

A very good Universal SACD/CD/DVD player can be had for for $200-$600
A very good 5.1 / 7.1 channel home theatre amplifier can be had for
$1000-$2000
A very good set of 5 indentical full-range speakers can be had for
about $2500 used (recommended on a budget) or at least double for new
speakers.
A very good subwoofer for about $1000.

TOTAL for an very good "audiophile system for the rest of us" - less
than $10,000.
And if you are prudent you can do it for half that price. (Used
audiophile speakers are a bargain.) Well within reach of most
"working" music lovers.

If you are foolish enough to spent money on a vinyl LP system and
expect to surpass the above $5K-$10K system than you had better take
on a second or third job.
Marry into a wealthy family. Pray and play the lottery or rob a bank -
LOL!