From: waardenb@cs.utwente.nl (Jerry van Waardenberg)
Subject: SOUNDCARDS: A summary
Keywords: Soundcards
Organization: University of Twente, Dept. of Computer Science
Date: Wed, 16 Dec 1992 09:17:29 GMT

**** SOUNDCARDS - Which is the best? ****

Two days ago I posted the first version of this article. I got
numerous replies of people who told me that I should set the
line-length to 65 chars instead of 80. So I hope this is
better (62-chars) :).

The text of this article is composed from a lot of messages of
different people. I hope they're not going to flame me for
taking their remarks and putting them into this article. But
anyway... Thanx to everyone who contributed to this article.

I'm not sure if everything in this article is correct. If you
find any mistakes, or have comments or suggestions, then let
me know by e-mail. The opinions in this article are my own;
other people might have other opinions (I certainly hope they
do ;-)).

**** INTRODUCTION

Generally PC's can produce music in four different ways,
dependent on the type of soundcard used:

1. By Digital to Analogue (D/A) conversion. Samples stored in
the computer's memory are digitally processed and transformed
to analogue signals, that can be played over a stereo set or
headphones.

2. By synthesis. The computer sends note-information to the
soundcard, which produces analogue signals. There are two
basic forms of synthesis: FM and wavetable synthesis.

3. By MIDI. Note-information is send through a MIDI-interface
to a MIDI-device, which produces the music. There are two MIDI
standards: General MIDI and Roland MPU-401. The latter is an
extended version of General MIDI.

4. Controlling a CD-ROM drive. The music is stored on CD-ROM
which is controlled by the computer.

** FM synthesis

With FM synthesis the tones are produced by
waveform-generators, called operators. The more operators are
used, the better the sound quality will be. A disadvantage of
FM synthesis is that it is very hard to produce realistic
sounding instruments, especially when playing high pitched
notes (reeds, guitar, etc.). The Adlib was the first soundcard
that used this technique, using a Yamaha YM3812 FM chip with
two operators. Most Adlib compatible cards (SoundBlaster, Pro
Audio Spectrum) are also using this techn ique. The newer
cards are mostly using the new Yamaha YMF262 (OPL-3) FM chip,
which has four operators.

** Wavetable synthesis (WS)

With WS (16-bit PCM) samples are used to produce sound. The
samples are stored in ROM or RAM on the soundcard. A
WS-processor performs operations on the samples, such as
altering their pitch and length. Since the samples are taken
from real instruments, they generally sound very realistic.
Until recently this technique was only used by high-end
soundcards, but it is becoming more and more popular now.
Examples of cards that use WS are the Gravis UltraSound and
the Roland SCC-1.

Some cards use a mixture of these techniques, such as the
Roland LAPC-1.

** Sampling

Most cards nowadays support sampling. Usually this is done in
8-bit or 16-bit resolution, but there are cards that use other
resolutions (Adlib Gold 1000 uses 12-bit sampling). Sampling
is done by a Analogue to Digital Converter (ADC). Samples can
be compressed by using PCM (Puls Code Modulation) or AD-PCM,
which is an variant of PCM that yields higher compression.
With AD-PCM the sound quality usually is less than with PCM.

** MPC (Multimedia PC) specifications.

A PC may be called a "Multimedia PC" (MPC) if it conforms to a
number of specifications. For the soundcards these specs are:

* 8-bit DAC (16-bit recommended) with PCM and 11 and 22 KHz
sampling. Processor load may not be more than 10%.
* 8-bit ADC (16-bit recommended) with PCM and 11 and 22 KHz
sampling.
* Microphone input.
* MIDI synthesizer, 6-tone polyphonic (6 tones at the same
time), FM-based and/or sample-based (WS). If sample-based, the
samples must at least be 8-bit.
* Audio mixer.

Since a MPC must be equipped with a CD-ROM, most soundcards
provide a CD-ROM interface, with a minimum throughput of 150
kB/sec.

** Channels, instruments and voices.

These words are common in the soundcard-business, but what do
they mean? It took a while before I understood what they were
and I am not sure if I do now, so correct me if I'm wrong.  I
will try to explain. Instruments and patches are synonyms. 
Each instrument can be played "through" a single channel. So
if a card has 8 channels, it means that it can play 8
instruments at the same time. And the number of voices (or
notes) is the number of instruments per channel. Let me try to
illustrate that with an example: Consider an orchestra divided
into 8 sections (channels). Each section plays one type of
instrument (patch). The orchestra can contain 16 musicians
(voices, notes), so there may be sections with more dan one
musician. Then we've got 8-channel, 16-voice sound.  Now you
see?


**** REVIEWED CARDS

I will give an overview of some cards that looked interesting
to me. Most of them were released only recently. The reviewed
cards are: The SoundBlaster Pro, the SoundBlaster 16, the Pro
Audio Plus/16, the Gravis UltraSound, the Roland LAPC-1 and
the Roland SCC-1. After that I'll give an short description of
some other cards. All these cards, except for the Rolands, are
MPC-compatible. 

** The SoundBlaster Pro (SB-pro)

The SoundBlaster (SB) from Creative Labs was the first Adlib
compatible card that, besides FM music, was capable of
recording and playing (8-bit) samples. The original SB
contained 1 (mono) or 2 (stereo) Yamaha YM3812 chips. The
first SB-pro was also equipped with 2 YM3812 chips, but the
newer version (SB-pro 2.0) contained the new OPL-3 chip.

The SB-pro is capable of 8-bit sampling at 44.100 Hz in stereo
and supports AD-PCM compression. It has a CD-ROM interface
which is only compatible with Matsushita drives. A General
MIDI interface is present. The SB-pro has a 2 x 4 Watts
amplifier. Volume can be altered manually on the back of the
card or by software.

Inputs:
* Microphone,
* external line in. Outputs:
* Audio
line out,
* SB compatible MIDI,
* SB CD-ROM interface.

The SB-pro is fully Adlib and SB compatible. It is supported
by a lot of games, but many of these games do not use the
extra possibilities of the Pro version.

Sampling quality of the SB-pro is good. Since it uses
FM-synthesis to generate sound, the SB-pro is not a good card
to produce high quality music. However, FM-synthesis in
combination with sampling produces good results for games.

The SB-pro comes with seven 5.25" DD disks or four 3.5" DD
disks, which contain drivers for Windows, demos and
applications. Interesting are Voice Edit 2, for recording and
editing samples. Unfortunately SB uses its own "voice" format
for storing these samples (.VOC files), instead of the more
general Windows-compatible "wave" format (.WAV files). The
Windows software consists of a simple but good Mixer program
and JukeBox, for playing MIDI files. The rest of the software
isn't much good, except for Voyetra (a MIDI sequencer).

PERSONAL OPINION: The big advantage of the SB is its support
by a lot of games. Too bad these games usually do not support
the extra capabilities of the SB-pro. Therefore, if you're
looking for a CD-ROM, I think you can better buy a normal SB
than a SB-pro. If you do want to have CD-ROM, you can better
take another card (read on!), since the SB-pro supports only
Matsushita CD-ROM drives.


** SoundBlaster 16

The SoundBlaster 16 (SB 16) is an improved version of the
SB-pro, that offers real 16 bit stereo sound. Of course the
SB16 is SB, SB-pro and Adlib compatible.

The SB-16 supports 8 and 16 bit stereo sampling and playing up
to 44.1 KHz, has dynamic filtering and ADPCM compression. It
also contains a 16 bit ASP (Advanced (Digital) Signal
Processor), which enables you to download a compression and/or
voice recognition algorithm. On-board real-time
(de)compression takes much load off the processor (up to 75%).
Decompression also minimizes the amount of data that must be
transferred from memory to the card (16 bit stereo sampling at
44.1 KHz requires 2x2x44 = 176 kB/se c uncompressed... *glug*
that really keeps your PC busy! No more smooth scrolling!).

Like the SB-pro the SB-16 has a Yamaha YMF262 (OPL-3)
synthesizer chip, with 4 voice operator FM synthesis. A
WaveBlaster MIDI module is optional. The WaveBlaster works
according to the General MIDI system and has 128 PCM sampled
sounds. (Is it LAPC-1/MT-32 compatible?) BTW: The WaveBlaster
can be connected to any General MIDI port, so it can be used
with the SB-pro or the PAS (see l8er) as well.

Inputs:
* Microphone,
* external line in.
Outputs:
* Audio line out,
* MPU 401 UART and SB compatible MIDI,
* SB CD-ROM interface.

The software consists of DOS and Windows drivers, Voyetra MIDI
sequencer, Voice Edit 2 (waveform editor) and some example
programs.

The sampling quality of the SB-16 is good, but there is quite
a lot of noise (I've heard this from someone who's reviewing a
test version, which may not be entirely correct. Maybe the
circuitry isn't shielded very good?). Since there is no
software for the SB-16 yet, the special capabilities cannot be
tested.

PERSONAL OPINION: Since it is a SoundBlaster, it is supported
by a lot of games. Together with the optional WaveBlaster it
forms a great, but quite expensive, combo. It's advantages are
its MPU-compatible MIDI interface, 16 bit sampling and ASP.
But it still has a SB-compatible CD-ROM interface instead of a
SCSI interface. I think it is best to wait until this card is
more supported.


** Pro Audio Spectrum Plus and Pro Audio Spectrum 16

The Pro Audio Spectrum Plus and -16 (PAS+ and PAS-16) from
Media Vision are probably the SB's main competitors when it
comes to Adlib compatible cards. Both cards are almost
identical, except that the PAS-16 has 16 bit sampling and the
PAS+ 8-bit.

The PAS-16 features 8, 12 and 16 bit stereo sampling and
playback (up to 44.1 KHz), dynamic filtering and ADPCM
compression and decompression. The PAS+ does not have 12 and
16 bit sampling.

Like the SB-pro and SB-16, the PAS has a Yamaha YMF262 (OPL-3)
synthesizer chip with 4 operator FM sounds. The PAS has
shielded circuitry and dynamic filtering.

Inputs:
* Microphone,
* External line in (stereo),
* PC speaker.
Outputs:
* Audio line out (headphones, amplifier),
* SCSI (not just for CD-ROM, but also for tape-streamers,
optical drives, etc),
* general MIDI (requires optional MIDI Mate),
* joystick.

S/N: 90 db.
Dynamic range: 90 db.
Harmonic distortion: 0.05%

The PAS-16 is one of the two cards I've tried myself (the
other is the GUS). The 16-bit samples sounds incredibly good.
The example MOD-files that come with the PAS-16 sound really
awesome (great stereo, no noise)!

The PAS16 comes with quite a lot of software (compared to the
other cards): Stereo Studio F/X is a waveform editor. It looks
very neat but is incredibly slow. SP Spectrum is a MIDI
sequencer. TrakBlaster Pro is a very nice MOD-player.
Furthermore, there is a mixer (supports "loudness", which
makes low pitched sounds come out better), a multimedia
application (Audio Mate) and a speech synthesizer (Pro
Speech). For Windows there are three (!!) mixers and a number
of drivers.

Although Media Vision claims the PAS is fully SB(-pro)
compatible, some people have problems when using the PAS as a
SB. It seems that the PAS is not 100% SB compatible.

PERSONAL OPINION: The PAS16 is a good soundcard and offers a
lot of value for your money. The 16-bit MOD files sound very
good. But playing MIDI songs through the internal FM chip is
quite a disappointment. I like the amount and quality of the
software that comes with the PAS16 and the standard SCSI
interface for CD-ROM. This, and the overall mechanical quality
of the card, IMHO makes the PAS a better card than the SB. Too
bad the PAS16 is not 100% compatible with the SB(-pro).


** The Gravis UltraSound

The Gravis UltraSound (GUS) from Advanced Gravis is a brand
new 16 bit soundcard that uses wavetable synthese (WS) to
generate sound. With WS 16-bit samples (called patches) are
used to generate sound effects and music. On the GUS, these
samples are stored in RAM.

Standard the GUS supports 8 bit stereo sampling and 16-bit
playback, up to 44.1 KHz. 16 bit recording is optional
(requires a 16-bit sampling card). It has 16 stereo channels
and 32 voice Wavetable Synthese, which enables you to create
very realistic instruments. Unlike the Roland SCC-1, the GUS
stores the samples for WS in RAM, so you have unlimited
possibilities. The instruments can be stored on disk and
downloaded to the card when needed. The GUS comes with 256 kB
RAM, but this seems a little too short. However, it can be
expanded to 1 MB. According to the importer (for the Benelux
this is Logitech), 1 MB will soon become the standard amount
of RAM for the GUS.

Inputs:
* Microphone,
* Audio Line In.
Outputs:
* Audio Line Out,
* Amplified Audio Out,
* speed compensating joystick (up to 50 Mhz),
* general MIDI (requires optional MIDI adapter),
* SCSI CD-ROM (requires optional SCSI interface card).

S/N: 80 db.
Dynamic range: 96 db.
Harmonic distortion: <0.014%

Gravis claims 100% compatibility with SB and Adlib. This
compatibility is achieved through software emulation by SBOS
(Sound Board Operating System). Unfortunately, in practice
SBOS is not 100% SB compatible. Newer releases are becoming
more compatible. Another big disadvantage of SBOS is that it
degrades performance considerable in some cases. In general
SBOS doesn't work good with demos and high speed animation. It
works o.k. with (for example) King's Quest VI, Dune and Links
386 Pro. Since the GUS has no FM-chip, the FM-sounds are
emulated through samples/patches. This results in slightly
different (but not worse) sounds than the SB.

All of this is not really a big problem, since the GUS is not
intended to be a SB clone. MIDI files, for example, sound very
good. If you play a piano-song, then you _hear_ a piano and a
guitar sounds like a guitar. As soon as software companies are
going to support the GUS directly, the sound quality will be
far better than a SB. Sierra already announced support for the
GUS.

The GUS has no special effects, like chorus and reverb. I am
not sure if the GUS has (dynamic) filtering, since
documentation is brief. The sound quality is very good, in
most cases even better than a Roland LAPC-1. However, the
sound quality of the GUS is dependent on the quality of the
patches. Some patches are not so good, so those instruments
sound worse.

The GUS is definitively not complete at this moment. The
software is flaky and is still being improved. Currently the
GUS comes with DOS and Windows drivers, Studio 8 (a 8 bit
waveform editor), UltraFli (Multimedia application for .fli
files) and PlayMidi (MIDI player and composer). The Windows
mixer is *very* (i.e. too) simple. At the moment, not even all
192 MIDI-patches are available.

Since the GUS is mainly software controlled, it is very
flexible. Gravis is still working on better software support
for the GUS. Rumours say they're working on a MOD-player and
MT-32/LAPC-1 emulation. With better software (and no doubt it
will be released soon) the GUS is going to be a very good
alternative for the FM-based cards. 

PERSONAL OPINION: The GUS seems to be a good soundcard. It
offers high (sound) quality for a low price. Unfortunately it
is not 100% SB compatible, but this may be solved by new
software patches. Since the card is becoming quite popular,
software developers will probably start to support it very
soon. The GUS is, at this moment, my favourite.


** The Roland LAPC-1 and SCC-1

The Roland LAPC-1 is a semi-professional soundcard based on
the Roland MT-32 module. In fact, the LAPC-1 is a MT-32 and
MPU MIDI-interface on a PC-card. The LAPC-1 contains 128 LA
(Linear Arithmetic) synthesized instruments. The LAPC-1 uses a
combination of samples and waveform synthesis to build a patch
(note): A patch consists of 4 "partials" that can be either a
sample or a linear part. The total number of partials is
limited to 32, up to 8 instruments can be played
simultaneously and each channel can pl ay up to 16 voices at
the same time. There is a 9th channel for percussion sounds
(MIDI channel 10). Besides 128 instruments, the LAPC-1 has 30
pre-sampled drum- and percussionsounds and 33 sound-effects.

The SCC-1 is the follow-up of the LAPC-1. Like the LAPC-1, it
is a module (in this case a CM-300) and a MPU-MIDI interface
on one card. The SCC-1 does not use waveform-synthesis, but
is fully WS-based. It contains 317 PCM samples in ROM. A
patch can consist of 24 partials, but most patches use only
one partial.  It has 15 channels for instruments (+ 1 for
percussion) and can play 24 voices simultaneously. The sounds
can be fully programmed, except for the samples.

The LAPC-1 has two special effects: hall and echo; the SCC-1
has chorus as well. The Roland cards do not have a DAC/ADC, so
it is not possible to record or play samples. They also don't
have a CD-ROM interface. This means that the Roland cards do
not conform to the MPC specifications.

The sound quality of the LAPC-1 is good. High pitched
instruments like piano or reeds do not sound as good as with
the GUS. The quality of the sound-effects in general is quite
good. The sound quality of the SCC-1 is outstanding. The PCM
samples are of high quality. The SCC-1 is not fully compatible
with the LAPC-1.

The LAPC-1 comes with no software at all. The SCC-1 only has a
program for enabling the MT-32 emulation mode.

PERSONAL OPINION: The Roland cards are good cards for making
music, especially since they contain a MPU-MIDI interface.
However, the cards are quite expensive and offer less
functionality than other cards. In combination with a cheap SB
the Roland cards are very nice (just listen to Space Quest IV
:^))! But I think the GUS comes close to this combo and it is
far less expensive. It's a pity that the SCC-1 does not have
RAM to store samples in.


** Other cards

Here follows a list of other popular cards, with a short
description of each card:

* Covox/Disney Sound Source. Simple DAC plugged into your
computers printer port.

* Adlib Gold 1000. Adlib and SB compatible card with SCSI and
General MIDI interface. Yahama OPL-3 FM chip. 20 channels,
1-voice polyphonic. Surround processor to improve sound
quality. 12 bit sampling and playing up to 44.1 KHz. Inputs:
Mic and Line. Outputs: Line.

* Adlib Gold 2000. Like the Adlib Gold 1000, but with 16 bit
sampling.

* Thunderboard. Predecessor of the PAS. Adlib and SB
compatible. Yamaha YMF3812 FM-chip. 11 channels, 1-voice
polyphonic. 8 bit mono sampling up to 22 KHz. SB-compatible
MIDI interface. Inputs: Mic. Outputs: Headphones.

* ATI-Stereo F/X. Adlib and SB-compatible. Yamaha YM3812
FM-chips. 11 channels, 1-voice polyphonic. 8 bit stereo
sampling up to 44.1 KHz. SB-compatible MIDI-interface. Inputs:
Mic, Line. Outputs: Line.

* Turtle Beach MultiSound. GM/GS compatible. Proteus-1/XR
soundchip. Motorola 56001 DSP. 384 pre-sampled 16-bit PCM
instruments. 15 channels + Drums, 32 voices. Special effects:
Hall, Chorus and Echo. 16 bit stereo sampling up to 44.1 KHz.
Turtle Beach compatible MIDI interface. Inputs: Aux, Line.
Outputs: Line. The specs of this card are impressive, but it
costs about $1000 !!! (You can buy 8 GUSses for that money
:-)).

[from Stefan Hartmann] * AudioBahn 16 from Genoa Systems.
Arial chip from Sierra semiconductor. Adlib and SB compatible
with MPU-401 MIDI interface and Adaptec SCSI interface. 1 MB
PCM samples in ROM. 32 voices simultaneously. 16 bit stereo
sampling at 44.1 KHz. MPC compatible. GREAT SPECS, BUT WHAT
ABOUT THE PRICE????

* Please mail me more...


**** CONCLUSION

Many manufacturers are now rapidly releasing new soundcards.
Game companies are already working on support of a new
generation of sound cards, that will offer significantly
better quality over the present cards. The GUS is an example
of a card with great potential. It's not the Ultimate Sound
Card, but it is probably the first of a whole series of high
quality cards.

Secondly I think the FM-based cards are rapidly going to be
replaced by WS-based cards, since WS gives much better sound
quality than FM.

Watch which cards the software companies are going to support.
If you want to buy a card now, go for a cheap sound card.
Maybe you can get an old SB for just a few bucks. If you want
a card with better sound quality, the GUS is a good choice.


**** NOTE

The information in this article may not be entirely correct or
up-to-date! Some info is from my own experience, other is from
different sources. If anyone finds any mistake, please let me
know. If you want to contribute to this article, please send
your info. I'll put it in a next release (if it's interesting
enough and if you want me to ;^))!

** Thanx to:

Josha Munnik (for lending me his lended GUS :^)), Bjorn
Haavard Kleven, Phat Tran and Stefan Hartmann (for their
useful tips and info on the newsnet), Timo Veijola (for his
info about the Roland cards) and all the other newsnetters.


Jerry


*--------------------------------------------------------------------------------*
Jerry van Waardenberg                                ______ ____  _____   _____
Tele Informatics and Open Systems                      /     /   /    /  /_
Department of Computer Science                        /     /   /    /     -_ 
University of Twente, Enschede, The Netherlands      /   __/_  /____/  _____/
E-mail: waardenb@cs.utwente.nl                  

Newsgroups: comp.sys.ibm.pc.hardware