Really basic soundcard question!

Please don't knock me for asking such a simplistic question, but I've
just had my eyes opened as to what a soundcard does, and I feel an
utter buffoon! This is what I, rightly or wrongly, used to think:-

1. A soundcard is needed to produce all those beep and pings etc. that
Windows does on certain actions (starting up and so on).
2. It doesn't matter if your PC doesn't have speakers, 'cause there's
some kind of little speaker on the soundcard.
3. When you play a MIDI file, the soundcard has 128 or whatever
pre-set sounds which it can play because something on the soundcard is
built to handle them.
4. When you play a music CD in your CD-ROM drive, that's a different
kettle of fish - because you have to do millions of different "human"
sounds, the soundcard is no good. Consequently, the sounds all come
from hardware in the CD-ROM unit (like hi-fi equipment in fact).

I've just started using mp3s though, and it's made me realise what a
load of cobblers the above must be! The mp3s deal with ANY sound, yet
are not remotely connected to the CD-ROM. Doh!

So - my question is this : do ALL sounds emanating from a PC always
come from the soundcard?

Thanks!

Somewhere on teh intarweb "Neil Grafton" typed:
> Please don't knock me for asking such a simplistic question, but I've
> just had my eyes opened as to what a soundcard does, and I feel an
> utter buffoon! This is what I, rightly or wrongly, used to think:-
>
> 1. A soundcard is needed to produce all those beep and pings etc. that
> Windows does on certain actions (starting up and so on).
> 2. It doesn't matter if your PC doesn't have speakers, 'cause there's
> some kind of little speaker on the soundcard.
> 3. When you play a MIDI file, the soundcard has 128 or whatever
> pre-set sounds which it can play because something on the soundcard is
> built to handle them.
> 4. When you play a music CD in your CD-ROM drive, that's a different
> kettle of fish - because you have to do millions of different "human"
> sounds, the soundcard is no good. Consequently, the sounds all come
> from hardware in the CD-ROM unit (like hi-fi equipment in fact).
>
> I've just started using mp3s though, and it's made me realise what a
> load of cobblers the above must be! The mp3s deal with ANY sound, yet
> are not remotely connected to the CD-ROM. Doh!
>
> So - my question is this : do ALL sounds emanating from a PC always
> come from the soundcard?

No.

> Thanks!

You're welcome.
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)

On Sun, 29 Jun 2008 10:41:56 GMT, neil.grafton@tivoli.net
(Neil Grafton) wrote:

>Please don't knock me for asking such a simplistic question, but I've
>just had my eyes opened as to what a soundcard does, and I feel an
>utter buffoon! This is what I, rightly or wrongly, used to think:-
>
>1. A soundcard is needed to produce all those beep and pings etc. that
>Windows does on certain actions (starting up and so on).

Yes, but certain error beeps can come from the motherboard
buzzer (or case speaker if motherboard has one attached by a
pin header).



>2. It doesn't matter if your PC doesn't have speakers, 'cause there's
>some kind of little speaker on the soundcard.

No sound card that I'm aware of has a speaker on it. Rarely
some very old (ISA?) soundcard modem combo cards had a
speaker because there was a modem, but it was not used for
anything other than modem phoneline sounds.



>3. When you play a MIDI file, the soundcard has 128 or whatever
>pre-set sounds which it can play because something on the soundcard is
>built to handle them.

Yes, the soundcard driver handles were the midi sounds come
from and sound card outputs it to the speakers plugged into
the sound card output jack.


>4. When you play a music CD in your CD-ROM drive, that's a different
>kettle of fish - because you have to do millions of different "human"
>sounds, the soundcard is no good. Consequently, the sounds all come
>from hardware in the CD-ROM unit (like hi-fi equipment in fact).

Either:

A) CDROM's internal circuitry outputs an analog or digital
audio signal, to either the CDROM's front headphone jack
through an opamp onboard, through an analog pin header on
the back to the analog input on the sound card, or through a
digital output on the back of the CDROM to the sound card
digital input.

B) Sound card streams digitally, data over the bus
(ATAPI/ATA, SATA, SCSI, etc) which the operating system and
audio player software play using the sound card driver, and
the sound card then outputs this to the speakers (or a
digital output to an external amplifier with a digital
input which then converts it to analog to external speakers.

If you plug headphones into the CDROM drive itself then A)
is true. If you plug headphones into a case front jack then
B) is true. If you listen over speakers or external amp +
speakers plugged into the rear sound card jack then B) is
true.

So in general your statement in #4 is false, usually in a
system that is old the CDROM's analog output goes to a sound
card input as already file-decoded analog sound but the
sound card itself still handles output to external amp or
speakers. In newer systems the data usually goes over the
CD drive's data bus and is decoded by the playback software
and OS directs this to driver to sound card to output
speakers or amp + speakers.


>
>I've just started using mp3s though, and it's made me realise what a
>load of cobblers the above must be! The mp3s deal with ANY sound, yet
>are not remotely connected to the CD-ROM. Doh!

CDROM onboard circuitry can only decode (AFAIK) a standard
audio CD to produce an analog output. Otherwise any media
files like MP3, WAV file, a DVD, etc, are data streamed over
the data bus to the player which decodes and sends it to
driver for soundcard which sound card outputs as digital to
an amp which converts to analog to speakers, or sound card
converts to analog onboard and outputs to amp analog input
or directly drives speakers and/or headphones.


>
>So - my question is this : do ALL sounds emanating from a PC always
>come from the soundcard?

In loose terms for the purposes of your speculation, yes
they all do. When you observe that a CDROM can output
analog or digital sound streams, it is something it can do
without the PC being involved, only as a standalone CD
player from an audio disc. It could do this if you had no
PC and just the CDROM drive on a live power supply and
pressed front panel playback buttons. Since most consumers
don't use one like this, many CDROMs omitted these buttons
to cut costs and that would make it necessary for the PC to
send the commands for playback to the drive IF someone
wanted to use it like this, but still most consumers (I
would assumed) choose to output the sound through the sound
card since the CDROM output can only do audio CDs but the
sound card can handle the audio CDs plus everything else
(except certain error beeps as mentioned above and those are
(hopefully) rare).

I'm sure there are other scenarios I haven't covered, but
these are the most common ones typical to all PCs.

Neil Grafton wrote:
> Please don't knock me for asking such a simplistic question, but I've
> just had my eyes opened as to what a soundcard does, and I feel an
> utter buffoon! This is what I, rightly or wrongly, used to think:-
>
> 1. A soundcard is needed to produce all those beep and pings etc. that
> Windows does on certain actions (starting up and so on).

Not anywhere near as true as in the past. These functions are now
included in many tower system and notebook motherboards.

> 2. It doesn't matter if your PC doesn't have speakers, 'cause there's
> some kind of little speaker on the soundcard.

No speakers on any of the several sound cards or motherboards I have
owned. There's a stereo headphone jack that was originally designed to
be compatible with extension speakers for the pocket cassette tape
players that were popular before portable CD players were widely
available. Some computer displays now include equivalent speakers.

> 3. When you play a MIDI file, the soundcard has 128 or whatever
> pre-set sounds which it can play because something on the soundcard is
> built to handle them.

Wave forms can be loaded into memory. The MIDI file contains pitch and
duration information that a sythysisor chip uses to reconstruct the
musical notes, typically insturmental.

> 4. When you play a music CD in your CD-ROM drive, that's a different
> kettle of fish - because you have to do millions of different "human"
> sounds, the soundcard is no good. Consequently, the sounds all come
> from hardware in the CD-ROM unit (like hi-fi equipment in fact).

A music CD contains a numerical representation of the performance's
(music or voice) audio waveform as generated by the microphone(s). At
one time most computers were equipped with a cable to transmit these
signals from the CD drive to the sound card, but most current models
utilize the CD's data cable and the computer's data buss to transmit the
raw digital data to the sound card or the equivalent circuitry on the
motherboard.

> I've just started using mp3s though, and it's made me realise what a
> load of cobblers the above must be! The mp3s deal with ANY sound, yet
> are not remotely connected to the CD-ROM. Doh!

MP3s are a form of the raw digital audio recording that's compressed to
reduce the amount of memory or hard drive space necessary to store it.
At some loss of quality a significantly longer playing program of MP3s
can be stored on a single CD than the uncompressed standard wave files.
there are even many DVD players that are able to play MP3s through the
speakers of the attached stereo TV.

> So - my question is this : do ALL sounds emanating from a PC always
> come from the soundcard?
>
> Thanks!

The Power On Self Test (POST) beeps that occur when a computer is
initially started usually come from a tiny speaker on the motherboard or
the interior of the tower case. Some internal Fax Modems also utilize a
mini speaker to relay the sound of dial tones and synchronization tones
during the connection process.

Somewhere on teh intarweb "RobertVA" typed:

> No speakers on any of the several sound cards or motherboards I have
> owned.

> The Power On Self Test (POST) beeps that occur when a computer is
> initially started usually come from a tiny speaker on the motherboard
> or the interior of the tower case.

?
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)

~misfit~ wrote:
> Somewhere on teh intarweb "RobertVA" typed:
>
>> No speakers on any of the several sound cards or motherboards I have
>> owned.
>
>> The Power On Self Test (POST) beeps that occur when a computer is
>> initially started usually come from a tiny speaker on the motherboard
>> or the interior of the tower case.
>
> ?

1) Jacks for microphones, line in, line out and speakers on the mounting
plate; but no devices on the sound board itself that actually produce
sounds. Even on the motherboards with built in sound accelerator
hardware (to assume functions sound cards used to serve) those sounds
require external speakers (only available as signals on the jacks).

2) The POST beeps are generated with code in the motherboard's ROM based
Basic Input/Output System (BIOS). Most motherboards generate a single
beep EARLY in startup, mostly as an indication that the case speaker is
operational. The POST beeps permit some very basic indications of what
is lacking with some low level failures like main memory and display
interface problems. The failure beep codes vary with the different
computer manufacturers. POST beeps became standard in the period before
sound cards became common, so there was no other way for the computer to
generate sounds at that time.

Somewhere on teh intarweb "RobertVA" typed:
> ~misfit~ wrote:
>> Somewhere on teh intarweb "RobertVA" typed:
>>
>>> No speakers on any of the several sound cards or motherboards I have
>>> owned.
>>
>>> The Power On Self Test (POST) beeps that occur when a computer is
>>> initially started usually come from a tiny speaker on the
>>> motherboard or the interior of the tower case.
>>
>> ?
>
> 1) Jacks for microphones, line in, line out and speakers on the
> mounting plate; but no devices on the sound board itself that
> actually produce sounds. Even on the motherboards with built in sound
> accelerator hardware (to assume functions sound cards used to serve)
> those sounds require external speakers (only available as signals on
> the jacks).

Perhaps I should have quoted that first bit as "No speakers on any of the
several [.....] motherboards I have owned."

> 2) The POST beeps are generated with code in the motherboard's ROM
> based Basic Input/Output System (BIOS). Most motherboards generate a
> single beep EARLY in startup, mostly as an indication that the case
> speaker is operational. The POST beeps permit some very basic
> indications of what is lacking with some low level failures like main
> memory and display interface problems. The failure beep codes vary
> with the different computer manufacturers. POST beeps became standard
> in the period before sound cards became common, so there was no other
> way for the computer to generate sounds at that time.

Aye, I'm familair with all that. My point is, you contradict yourself. First
you say no speakers on any mobos you'bve owned, then you say beeps coming
froma tiny speaker "on the motherboard" (or interior of case).

I've seen lots of mobos with peizo speakers built-in. Little cylindrical
black things with a hole in the top usually. They're also common on modems
but I've never seen one on a soundcard.
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)

Wow! Thanks to all you guys for sharing your expertise. I know it can
sometimes be a drag to explain what is common knowledge in some
circles, but I do appreciate your well thought-out replies. They HAVE
helped my understanding, and also taught me that I should never try
and simplify my reasoning, ha ha. There's obviously a bit more to a PC
than wikipedia would suggest, hence my asking the experts!

Thanks again!

On Mon, 30 Jun 2008 22:39:20 +1200, "~misfit~"
<misfit61nz@hooya.com.au> wrote:


>Aye, I'm familair with all that. My point is, you contradict yourself. First
>you say no speakers on any mobos you'bve owned, then you say beeps coming
>froma tiny speaker "on the motherboard" (or interior of case).
>
>I've seen lots of mobos with peizo speakers built-in. Little cylindrical
>black things with a hole in the top usually. They're also common on modems
>but I've never seen one on a soundcard.

Every now and then I come upon a board with no buzzer
onboard but that has the ability to use the onboard sound to
output the POST beeps to the sound card connected speakers.
In some ways that's nice, and in others it's a bit annoying
because it (one system I have in mind) then makes a pretty
*LOUD* beep every time it's turned on.

Often I've bought Asus boards without the onboard buzzer but
it had a spot on the PCB for one and any needed support
traces and components were in place. IOW, if one had a
spare buzzer or a pin header they could solder that on to
have the onboard or lead connected case speaker added
themselves, fairly easily.