Digital reproduction

[Nino]

Hi. I have one newbie question. If i want to play some audio source that is
connected to my receiver with some digital link ie. optics then some logic
tells me that there should be no difference if i played it from some crapy
mobile phone (if it can send digital signal through ie. optics) or some high
end audio box? Is this true? I mean in digital world 1 is always 1 and 0 is
always 0 so if the rigth bits come from source to receiver that's it.
Regards.

[Don Pearce[_3_]]

On Sun, 22 Aug 2010 17:00:39 +0200, "Nino" > wrote:

>Hi. I have one newbie question. If i want to play some audio source that is
>connected to my receiver with some digital link ie. optics then some logic
>tells me that there should be no difference if i played it from some crapy
>mobile phone (if it can send digital signal through ie. optics) or some high
>end audio box? Is this true? I mean in digital world 1 is always 1 and 0 is
>always 0 so if the rigth bits come from source to receiver that's it.
>Regards.
>

Yes and no (sorry about that). While the mobile phone's digital
connection should be capable of supplying the quality you are looking
for, it is unlikely that the music is unlikely to be stored on the
phone in a high quality format. It will be an MP3 in all probability.
MP3 files' quality varies from indistinguishable from the original to
truly dire. This depends on how small the final file is.

d

[Don Pearce[_3_]]

On Sun, 22 Aug 2010 15:10:28 GMT, (Don Pearce) wrote:

>On Sun, 22 Aug 2010 17:00:39 +0200, "Nino" > wrote:
>
>>Hi. I have one newbie question. If i want to play some audio source that is
>>connected to my receiver with some digital link ie. optics then some logic
>>tells me that there should be no difference if i played it from some crapy
>>mobile phone (if it can send digital signal through ie. optics) or some high
>>end audio box? Is this true? I mean in digital world 1 is always 1 and 0 is
>>always 0 so if the rigth bits come from source to receiver that's it.
>>Regards.
>>
>
>Yes and no (sorry about that). While the mobile phone's digital
>connection should be capable of supplying the quality you are looking
>for, it is unlikely that the music is unlikely to be stored on the
>phone in a high quality format. It will be an MP3 in all probability.
>MP3 files' quality varies from indistinguishable from the original to
>truly dire. This depends on how small the final file is.
>
>d

Sorry about all those "unlikely"'s. Always read after you edit.

d

[Ethan Winer[_3_]]

I would expect any digital device to be able to play a file in
whatever format through a digit output, without compromising whatever
fidelity the file has. I believe this is what the OP was asking. Also,
lossy-compressed files are not terrible if the bit-rate is high
enough, say 192 or 256 kbps.

--Ethan

[Nino]

"Ethan Winer" > wrote in message
...
>I would expect any digital device to be able to play a file in
> whatever format through a digit output, without compromising whatever
> fidelity the file has. I believe this is what the OP was asking. Also,
> lossy-compressed files are not terrible if the bit-rate is high
> enough, say 192 or 256 kbps.

I think you didn't uderstand what i have asked. So to make it short. Is
there a difference when playing digital audio from some ultra low cost
player and high end one while that same player is connected to receiver via
ie. optical cable? There should be no difference because it's digital
signal/data. Thx.

[Scott Dorsey]

In article >, Nino > wrote:
>Hi. I have one newbie question. If i want to play some audio source that is
>connected to my receiver with some digital link ie. optics then some logic
>tells me that there should be no difference if i played it from some crapy
>mobile phone (if it can send digital signal through ie. optics) or some high
>end audio box? Is this true? I mean in digital world 1 is always 1 and 0 is
>always 0 so if the rigth bits come from source to receiver that's it.

If the crappy mobile phone could send uncompressed audio data, it would be
just as good as anything else that can send uncompressed audio data.

The problem, unfortunately, is that most consumer devices employ compression
and once you have used lossy compression, all of the serious advantages of
digital recording fly out the window.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[John Williamson]

Nino wrote:
> "Ethan Winer" > wrote in message
> ...
>> I would expect any digital device to be able to play a file in
>> whatever format through a digit output, without compromising whatever
>> fidelity the file has. I believe this is what the OP was asking. Also,
>> lossy-compressed files are not terrible if the bit-rate is high
>> enough, say 192 or 256 kbps.
>
> I think you didn't uderstand what i have asked. So to make it short. Is
> there a difference when playing digital audio from some ultra low cost
> player and high end one while that same player is connected to receiver via
> ie. optical cable? There should be no difference because it's digital
> signal/data. Thx.
>
>
If you take *identical* files, they will sound identical. If you have,
say, a really cheap and nasty CD player with a digital output and a
really expensive CD player with a digital output, and a bit for bit copy
of the file from the CD on a portable player with a digital output,
you're unlikely to notice the difference.

Put any of these players up against a copy of the same source material
as typically stored on an mp3 player or phone, again through a digital
link, then you may well notice the difference, depending on the amount
of digital compression used by the storage device. A common
misconception is that all digital sound recordings are perfect
representations of the original source.

In practice, cheap portable devices compress the files to store them
more cheaply, and they do this by throwing data, and hence sound
quality, away.

--
Tciao for Now!

John.

[Mike Rivers]

Nino wrote:

> I think you didn't uderstand what i have asked. So to make it short. Is
> there a difference when playing digital audio from some ultra low cost
> player and high end one while that same player is connected to receiver via
> ie. optical cable? There should be no difference because it's digital
> signal/data. Thx.

I think you're hoping for a general "no" but there are some
instances where there could be a difference in sound due to
differences in jitter, if the receiver's input doesn't
sufficiently suppress jitter. But I think that it would be
safe to say that you wouldn't notice a difference, given
the general nature of your question.

What are you worried about?

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

[alex]

On 22/08/2010 17:00, Nino wrote:
> Hi. I have one newbie question. If i want to play some audio source that is
> connected to my receiver with some digital link ie. optics then some logic
> tells me that there should be no difference if i played it from some crapy
> mobile phone (if it can send digital signal through ie. optics) or some high
> end audio box? Is this true? I mean in digital world 1 is always 1 and 0 is
> always 0 so if the rigth bits come from source to receiver that's it.
> Regards.
>
>
the answer is no. a digital transfer cannot add signal change by definition.
this as a starting point.
providing that the source digital machine and the destination machine
are not doing some "nasty", hidden sample rate conversion and you didn't
loss data packets via the digital connection itself, the data should
arrive untouched.
be aware that there are different bitdepth available for spdif, 20 and
24 bits.
be also aware that not all spdif sources are capable of multichannel
audio such ac3.
Once i had a soundblaster live soundcard that always output data via
spdif at 48kHz even with a 44.1kHz source. the same for the digital
input! So transferring my old dat tapes at 44100 in my computer, i got
some 44100 files passed trough a double and "hidden" rate conversion
made by the board.

alex

[Nino[_2_]]

"Don Pearce" > wrote in message
...
> On Sun, 22 Aug 2010 17:00:39 +0200, "Nino" > wrote:
>
>>Hi. I have one newbie question. If i want to play some audio source that
>>is
>>connected to my receiver with some digital link ie. optics then some logic
>>tells me that there should be no difference if i played it from some crapy
>>mobile phone (if it can send digital signal through ie. optics) or some
>>high
>>end audio box? Is this true? I mean in digital world 1 is always 1 and 0
>>is
>>always 0 so if the rigth bits come from source to receiver that's it.
>>Regards.
>>
>
> Yes and no (sorry about that). While the mobile phone's digital
> connection should be capable of supplying the quality you are looking
> for, it is unlikely that the music is unlikely to be stored on the
> phone in a high quality format. It will be an MP3 in all probability.
> MP3 files' quality varies from indistinguishable from the original to
> truly dire. This depends on how small the final file is.
>
> d

Sorry, i didn't mention.. I'm talking about FLAC (uncompressed) audio. I can
play those on mobile.. But i wrote mobile just as an example of some crapy
audio playing device. It doesn't matter is that a mobile phone or some ultra
low cost equipment.

[Nino[_2_]]

"Mike Rivers" > wrote in message
...
> Nino wrote:
>
>> I think you didn't uderstand what i have asked. So to make it short. Is
>> there a difference when playing digital audio from some ultra low cost
>> player and high end one while that same player is connected to receiver
>> via ie. optical cable? There should be no difference because it's digital
>> signal/data. Thx.
>
> I think you're hoping for a general "no" but there are some instances
> where there could be a difference in sound due to differences in jitter,
> if the receiver's input doesn't sufficiently suppress jitter. But I think
> that it would be safe to say that you wouldn't notice a difference, given
> the general nature of your question.
>
> What are you worried about?

Well.. i have Onkyo 307 receiver and sound from radio stations is really
very good. But when i play some mp3 (from TV :-) via optical link sound is
not so good. It could be due to a mp3 format but i'm not sure if radio
stations enhance audio data in some way? Do they do this? In near future i
will be playing FLACs (uncompressed audio) from my computer via hdmi or
optics connected to receiver so i was wandering if i should do something
more to enhance quality of sound.

[Nino[_2_]]

"Scott Dorsey" > wrote in message
...
> In article >, Nino > wrote:
>>Hi. I have one newbie question. If i want to play some audio source that
>>is
>>connected to my receiver with some digital link ie. optics then some logic
>>tells me that there should be no difference if i played it from some crapy
>>mobile phone (if it can send digital signal through ie. optics) or some
>>high
>>end audio box? Is this true? I mean in digital world 1 is always 1 and 0
>>is
>>always 0 so if the rigth bits come from source to receiver that's it.
>
> If the crappy mobile phone could send uncompressed audio data, it would be
> just as good as anything else that can send uncompressed audio data.
>
> The problem, unfortunately, is that most consumer devices employ
> compression
> and once you have used lossy compression, all of the serious advantages of
> digital recording fly out the window.
> --scott

Yep, this is what i was asking. Basicly one can u use really cheap audio
player (if u don't need some extra sound processing and other features) for
playback of digital uncompressed audio data unlike analog world where you
can't do this.

[John Williamson]

Nino wrote:
> "Mike Rivers" > wrote in message
> ...
>> Nino wrote:
>>
>>> I think you didn't uderstand what i have asked. So to make it short. Is
>>> there a difference when playing digital audio from some ultra low cost
>>> player and high end one while that same player is connected to receiver
>>> via ie. optical cable? There should be no difference because it's digital
>>> signal/data. Thx.
>> I think you're hoping for a general "no" but there are some instances
>> where there could be a difference in sound due to differences in jitter,
>> if the receiver's input doesn't sufficiently suppress jitter. But I think
>> that it would be safe to say that you wouldn't notice a difference, given
>> the general nature of your question.
>>
>> What are you worried about?
>
> Well.. i have Onkyo 307 receiver and sound from radio stations is really
> very good. But when i play some mp3 (from TV :-) via optical link sound is
> not so good. It could be due to a mp3 format but i'm not sure if radio
> stations enhance audio data in some way? Do they do this? In near future i
> will be playing FLACs (uncompressed audio) from my computer via hdmi or
> optics connected to receiver so i was wandering if i should do something
> more to enhance quality of sound.
>
>
Almost all radio stations use an Optimod or similar multi-band
compressor on the way from the studio to the transmitter, which makes
the sound more uniform and tailored to sound the way they want it to. It
also makes for better intelligibility at the edges of their reception area.

What bit rate are your mp3s? Bit rates under 192 Kbps usually sound
noticeably worse than CD quality. 128K is what I would regard as
cassette quality, though some put that boundary at 96K.

--
Tciao for Now!

John.

[Nino[_2_]]

"John Williamson" > wrote in message
...
> Nino wrote:
>> "Mike Rivers" > wrote in message
>> ...
>>> Nino wrote:
>>>
>>>> I think you didn't uderstand what i have asked. So to make it short. Is
>>>> there a difference when playing digital audio from some ultra low cost
>>>> player and high end one while that same player is connected to receiver
>>>> via ie. optical cable? There should be no difference because it's
>>>> digital signal/data. Thx.
>>> I think you're hoping for a general "no" but there are some instances
>>> where there could be a difference in sound due to differences in jitter,
>>> if the receiver's input doesn't sufficiently suppress jitter. But I
>>> think that it would be safe to say that you wouldn't notice a
>>> difference, given the general nature of your question.
>>>
>>> What are you worried about?
>>
>> Well.. i have Onkyo 307 receiver and sound from radio stations is really
>> very good. But when i play some mp3 (from TV :-) via optical link sound
>> is not so good. It could be due to a mp3 format but i'm not sure if radio
>> stations enhance audio data in some way? Do they do this? In near future
>> i will be playing FLACs (uncompressed audio) from my computer via hdmi or
>> optics connected to receiver so i was wandering if i should do something
>> more to enhance quality of sound.
> Almost all radio stations use an Optimod or similar multi-band compressor
> on the way from the studio to the transmitter, which makes the sound more
> uniform and tailored to sound the way they want it to. It also makes for
> better intelligibility at the edges of their reception area.
>
> What bit rate are your mp3s? Bit rates under 192 Kbps usually sound
> noticeably worse than CD quality. 128K is what I would regard as cassette
> quality, though some put that boundary at 96K.

What i need to do is to connect some piece od audio equipment (my PC most
likely) via hdmi or optics to receiver and to play uncompressed audio. But
unfortunatelly i can only connect TV in such a way (TV plays only mp3) for
now. If the sound will still be inferior to radio stations then i will do
some audio processing on PC (compressor) :-) Thx. for info!

[Arny Krueger]

"Nino" > wrote in message

> Hi. I have one newbie question. If i want to play some
> audio source that is connected to my receiver with some
> digital link ie. optics then some logic tells me that
> there should be no difference if i played it from some
> crapy mobile phone (if it can send digital signal through
> ie. optics) or some high end audio box? Is this true? I
> mean in digital world 1 is always 1 and 0 is always 0 so
> if the rigth bits come from source to receiver that's it.

Digital signals are composed of both numerical data and also timing
information. The timing information is commonly implicit in the data
transmission although some systems for data transmission such as I2S
separate the timing information in the interest of simplicity and precision.

In times past, a source that delivered digital data with slightly
inconsistent timing could cause audible problems when the timing variations
were not corrected during the process of converting the digital data to an
analog signal. Minor timing variations can be audible as an added wavery or
watery quality in the sound.

Most modern digital to analog converters also include circuits that correct
these minor variations in timing.

Timing variations are usually little cause for concern today unless they are
so great that make it impossible to accurately interpret the numerical
information. If these kind of timing variations occur, then the audio signal
will be contaminated with occasional clicks and pops.

[William Sommerwerck]

> In times past, a source that delivered digital data with slightly
> inconsistent timing could cause audible problems when the
> timing variations were not corrected during the process of
> converting the digital data to an analog signal. Minor timing
> variations can be audible as an added wavery or watery
> quality in the sound.

Yes, early CD players were notorious for their high audible levels of wow
and flutter.

The question of whether digital timing errors are audible remains (to my
mind) debatable. But they are so small that it's hard to see how they could
be audible as flutter.

[Arny Krueger]

"William Sommerwerck" > wrote in
message

>> In times past, a source that delivered digital data with
>> slightly inconsistent timing could cause audible
>> problems when the
>> timing variations were not corrected during the process
>> of converting the digital data to an analog signal.
>> Minor timing variations can be audible as an added
>> wavery or watery
>> quality in the sound.

> Yes, early CD players were notorious for their high
> audible levels of wow and flutter.

Interesting, since I've measured a number of them and found nothing to worry
about. The worst thing about first generation CD players was their reaction
to media read errors.

CD players have always have a very strong jitter-reduction buffer, usually
clocked by a PLL. The digital signal that comes out out of the
photodiode(s) is pretty crappy.

Some of the worst jitter situations in audio history came about when people
started trying to *improve* their CD players with external DACs.

> The question of whether digital timing errors are audible remains (to my
> mind) debatable.

The tics and pops that I described are due to digital timing errors and are
very audible when they happen. The watery sound can be audible but it is
often less obvioius.

> But they are so small that it's hard to see how they could be audible as
> flutter.

If it wasn't for that buffer in CD players, we'd all know very well what
digital flutter sounded like. CD players have strong two primary sources -
rotation of the CD and data framing. Secondary sources include power line
hum.

[Scott Dorsey]

In article >, Nino > wrote:
>
>Well.. i have Onkyo 307 receiver and sound from radio stations is really
>very good. But when i play some mp3 (from TV :-) via optical link sound is
>not so good. It could be due to a mp3 format but i'm not sure if radio
>stations enhance audio data in some way? Do they do this? In near future i
>will be playing FLACs (uncompressed audio) from my computer via hdmi or
>optics connected to receiver so i was wandering if i should do something
>more to enhance quality of sound.

What radio stations do is to shred and destroy the sound. We have a local
station in town that has three different layers of lossy compression between
the disc and the tower. Combine that with aggressive audio processing to
make the station sound louder, and it's a wonder you can even understand the
words.
--scott


"It's supposed to sound good in your car, it's not supposed to sound good
in a controlled listening environment. People listen in their cars."
-- engineer, WTAR-AM

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[William Sommerwerck]

> If it wasn't for that buffer in CD players, we'd all know very well
> what digital flutter sounded like. CD players have strong two
> primary sources -- rotation of the CD and data framing.

I see what you mean. CDs are CLV, which doesn't lend itself to
constant-speed data transfer.

I have a Discman that (apparently) saves energy by "kicking" the drive motor
once in a while, rather than trying to main a
"fixed-but-continually-slowing" speed. The buffer takes care of the
resulting high variation in data-transfer rates.

My comments were based on the (reasonable) assumption that we don't commonly
listen to unbuffered data streams.

[William Sommerwerck]

> "It's supposed to sound good in your car, it's not supposed
> to sound good in a controlled listening environment. People
> listen in their cars." -- engineer, WTAR-AM

What wonderful call letters for a station with bad sound.

[Mike Rivers]

Nino wrote:
> "Mike Rivers" > wrote in message
> ...

> Well.. i have Onkyo 307 receiver and sound from radio stations is really
> very good. But when i play some mp3 (from TV :-) via optical link sound is
> not so good. It could be due to a mp3 format but i'm not sure if radio
> stations enhance audio data in some way?

Radio stations very often muck with the sound on the way to
the transmitter. Their goal is to make the same music played
on their station seem more appealing, or at least more
attention-grabbing, to the listener than when it's played by
another station. They sell more commercials that way because
they get more people dwelling on the station. Generally it's
a process that involves multi-band compression and some
equalization. Rest assured, what you hear coming off the air
sounds quite different (for better or worse - it's a matter
of perspective) from if you played the CD through the same
system.

TV audio, on the other hand, sucks. Generally it's badly
miked, badly mixed, and goes through all sorts of format
conversions and data compression between the production room
and the TV receiver.

> In near future i
> will be playing FLACs (uncompressed audio) from my computer via hdmi or
> optics connected to receiver so i was wandering if i should do something
> more to enhance quality of sound.

A FLAC version of a good recording sounds very good. Don't
muck with it. Just be sure you have a good source, or play
around with the source to your liking. Then when you FLAC
it, it should sound very close to what you started with
regardless of how it gets from your computer to your receiver.

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

[Ethan Winer[_3_]]

On Aug 22, 3:30 pm, "Nino" > wrote:
> I think you didn't uderstand what i have asked. So to make it short. Is
> there a difference when playing digital audio from some ultra low cost
> player and high end one while that same player is connected to receiver via
> ie. optical cable? There should be no difference because it's digital
> signal/data. Thx.
>
> I'm talking about FLAC (uncompressed) audio.

I understood you perfectly, though I did make a typo writing digit
instead of digital. Whether MP3 or FLAC audio, or serial data over a
Com port or Ethernet network, a digital stream is very robust. I'm
sure if you listen it sounds fine, no?

--Ethan

[Don Pearce[_3_]]

On Mon, 23 Aug 2010 10:57:32 +0200, "Nino" > wrote:

>
>"Don Pearce" > wrote in message
...
>> On Sun, 22 Aug 2010 17:00:39 +0200, "Nino" > wrote:
>>
>>>Hi. I have one newbie question. If i want to play some audio source that
>>>is
>>>connected to my receiver with some digital link ie. optics then some logic
>>>tells me that there should be no difference if i played it from some crapy
>>>mobile phone (if it can send digital signal through ie. optics) or some
>>>high
>>>end audio box? Is this true? I mean in digital world 1 is always 1 and 0
>>>is
>>>always 0 so if the rigth bits come from source to receiver that's it.
>>>Regards.
>>>
>>
>> Yes and no (sorry about that). While the mobile phone's digital
>> connection should be capable of supplying the quality you are looking
>> for, it is unlikely that the music is unlikely to be stored on the
>> phone in a high quality format. It will be an MP3 in all probability.
>> MP3 files' quality varies from indistinguishable from the original to
>> truly dire. This depends on how small the final file is.
>>
>> d
>
>Sorry, i didn't mention.. I'm talking about FLAC (uncompressed) audio. I can
>play those on mobile.. But i wrote mobile just as an example of some crapy
>audio playing device. It doesn't matter is that a mobile phone or some ultra
>low cost equipment.
>

Ok. Yes go ahead - it will be fine. When digital "goes bad" it doesn't
result in slightly poor sound, but in massive clicks and buzzes, so
you will know.

d