From: woodson@cse.ucsc.edu (Morgan Woodson )
Newsgroups: comp.sys.ibm.pc.soundcard
Subject: Re: Wave Blaster?!?
Followup-To: comp.sys.ibm.pc.soundcard
Date: 29 Jan 1993 03:21:40 GMT
Organization: University of California, Santa Cruz (CE/CIS Boards)
Distribution: world
NNTP-Posting-Host: arapaho.ucsc.edu
Summary: Clearing up some misconceptions on WaveBlaster
Keywords: WaveBlaster SoundBlaster 16 ASP Gravis UltraSound GUS SB16 gnarl

Where do you guys get your information???? This misinfo keeps going around:

>Since EMU is now owned by CL it is likely that the WB will make it to the
>retail market. Most estimates for combined SB+WB cost are around $330. High,
>but significantly less than a Roland or Multisound. Plus you get support
>for all games that use the SB.
[ -- 8 bit complaints deleted ---]  
>          Tom Sorensen

[[[  E-Mu Systems, Inc. is in negotiation for a stock-swap merger with
Creative Technologies of Singapore, to take place around March 1st,
at which point E-Mu becomes a wholly-owned subsidiary.  Creative
Labs of Milpitas, California is also a wholly-owned subsidiary
of Creative Tech.  Creative Tech. does more than make soundcards
and owns more than E-Mu and Creative Labs, so the picture is not
as simple folks paint it (E-Mu in Creative's "lap"). ]]]

In article <1993Jan21.204204.25111@frmug.fr.mugnet.org> 
zarkdav@frmug.fr.mugnet.org (Benjamin Ryzman) writes:
>gt0040a@prism.gatech.EDU (Tom Sorensen) writes:
>> In <wfIGG0O00iV3A4Ats3@andrew.cmu.edu> kc3b+@andrew.cmu.edu (Kevin
>Wengcheong Cheng) writes:
>> 
>> >>voice wave-table synthesis technology and is exclusively
>> >>licensed from E-mu Systems.

If it was the same thing as the Multisound, would it be exclusive? I tought
so. It is the lower grade unit that is on the wave blaster.

[[[me- this >>> is getting complicated:  E-Mu Systems, Inc. uses two sound
generation ASICs in all of its products: the G1.0 in the Emax II, Emulator
IIIx and Procussion, and G1.5 in Proteus 1 Pop/Rock, 2 Orchestral, 3
World, Vintage Keys, MPS keyboard and Proformance piano module.  (the
SP1200 is an eight-bit companded older product that was given a short
production run because used prices were around 80% of new, so we thought
we'd make a little $$ also).

The G1.5 is essentially a G1.0 with the MIXchip (32 to 8 digital mixer)
and the UART for MIDI integrated to reduce cost.

The OEM SoundEngines (tm):
8801 (4 MB masked, surface mount ROM)
8803 (4 MB DIP ROM)
8804 (8 MB masked, surface mount ROM)
8805 (4 MB masked, surface mount ROM and effects like MPS keyboard)

are all G1.5 based.

These are all 3.5" by 5" boards.  The WaveBlaster is an 8801 with the
General MIDI ROMs.  There is also a chip set, 8301, which is the G1.5,
sound ROMs, and firmware for a 68000.  This is what Turtle Beach uses
for the Multisound card.  I believe they acquire Motorola 68000s
themselves, but they definitely use their own DACs.

We have sound ROMs masked for Prot 1, 2, 3, Vintage and General
MIDI.  If you pay the $30,000 to $40,000 masking charge, we'll make
you another set.  Turtle Beach chose the Proteus 1 set and created
presets to emulate the 128 General MIDI patches before we had
a General MIDI set.

Now this is where things get grey- I called someone to bitch about
him saying the WaveBlaster was lower grade than the Multisound and
said "yo, I work at E-mu, so trust me, I know this stuff & I have
a Multisound and a SB16+WB & I don't have to rely on engineering
documentation or anyone's say so- I can eyeball the damn things &
see that they're the same."  OK, he says, but the sound ROMs are different.
Yee gads- this is true, but the intent of postings around this ngroup
have been that the technology on the WaveBlaster was inferior.

OK- What is General MIDI?  It is a bunch of music patches, but it also
includes some less conventional instruments and sound effects.  What's
a Proteus/1 module?  It's intended for people playing Rock and Pop music
who want some gnarly synth leads, string washes, guitar buzzes and punchy
drum sets.  So are they going to sound the same?  Of course not!  The
Multisound cannot hope to do some of the sound effects well, no matter
what you do to the patches, 'cause that samples can't change.  The General
MIDI set has some room taken by koto and helicopter, so it has to
sacrifice some room from pizz violin.  But the basic technology is the
same.  COMMENTS CONTINUE AFTER SOME MORE WORDS FROM OUR SPONSOR]]]

>> >OK, what I'd like to know is that since the Wave Blaster seems to be
>> >using wave-table sysnthesis too, wouldn't it sound as good as the GUS?
>> No. It'll sound better. *MUCH* better. The Waveblaster uses the EMU

You must be joking? The DOC II is a better synth chip that the EMU. Also,
the most important point in getting a good sound reproduction is the DAC.
On the multisound you have a 1 bit sigma delta with 64x oversampling DAC.
On the GUS it is a 16 bit dac and on the wave blaster it uses the DAC on
the SB16ASP which has a lower S/N ratio than the GUS.

>Please do not forget that the Wave Blaster has a MIDI brother, the Midi
>Blaster, which is the same, except bundled as a midi expander. So you will
>be able to connect it to the GUS and use its functionnalities like a SB16
>would...

Why would anyone want to do that?

Ciao,
--
Francois Dion

[[[ FIRST, The MIDI Blaster is based on the Dream chip from a company in
France, not E-Mu's G-chip.  We consider the chip inferior because of its
pitch-shifting method.  This leads me to my second point.

DACs are damned important, but every E-Mu synth and sampler does NOT
use oversampling, including the EIIIxp that was probably used to foley
the last movie you saw.  Good filters, like you get with oversampling or
delta-sigma converters, are much more important for ADC (analog to
digital converters), where freq's above the Nyquist will be reflected
down into the audible range.  A cheap filter on a DAC will let ultrasonic
frequencies through, but the Nyquist on a WaveBlaster is over 19 kHz- you
couldn't hear it even if the reconstruction filter wasn't there.

The important thing, again, is the filter on the ADC, which in WaveBlaster's
case, is the Emulator III that created its samples.

The other thing is the interpolating filter/pitch-shifter.  With ROMs still
more costly than air, you cannot have a sample for every key on a (musical)
keyboard.  Therefore, you must "stretch" some samples across a few keys.  The
sound quality comes from how far you have to stretch and how good your
stretching is.  Shifting up is harder, so lets talk about methods:

1. Drop sampling:  to double pitch, scan the wavetable twice as fast
   and skip every other sample.  Sounds terrible.

2. Linear interpolation:  Figure out where your next sample should come
   this will be a fraction into a table with integer indices, so take
   the samples on either side of where you'd like to be and interpolate
   between them.  Look at a sine wave created this way- you can see
   the points where samples actually exist as points and the rest as
   STRAIGHT lines between them.   The "jagged" edges (on an oscilloscope)
   create higher frequency components (seen on a spectrum analyzer),
   known as aliasing, which also sounds terrible.

3. Multi-point interpolation:  Do the above, but with more points-
   sine wave on oscilloscope looks less jagged as #points goes up,
   spectral analyzer shows lower amplitude and fewer higher frequency
   components and sounds a hell of a lot better.

Also, when you start doing math on 16 bit samples, you find that you need
to keep more than 16 bits in the intermediate stages- you can truncate
back down to what your DACs can handle at the end.  That's why the
Motorola DSP56001 has a 24 bit data path and 56 bit accumulators.  The
quantization effects influence what you choose for filter coefficients in
your interpolator.  The folks at E-Mu (I don't get involved in this part)
are verrrry careful about their mathematical modeling & have good ears.

A note to stem some flames- I'm not just expounding on math- I've HEARD
the effects of various interpolation methods.  I do belive that no amount
of math can explain away bad sound.

OK, so the claim is that the DOC II chip is better.  This is where I
stop explaining & ask a question- proof?  Have you heard both?  Do you
have some spec.s?  I'm afraid I've been paying more attention to
Kurzweil's MASS system, which is a more serious competitor to E-Mu stuff,
though don't let anyone tell you it's a K2000- the sounds come from
the K2000 library, but the chip is from the Mark 10 and Mark 150 digital
pianos.

OOOPS one more point- the WaveBlaster does NOT use the DACs on the
SB16.  It has two Burr-Brown PCM56Ps or Analog Devices equivs. (I'm
not revealing secrets here- go buy one and look at it) and a 5532
dual op-amp for reconstruction filter feeding through the header to
the SB16's analog mixer.

And here I would argue that it isn't the DAC, but the analog design that
matters most after you stop worrying about the original samples, the
modulation you can apply to them and how the interpolator works.  PCM56Ps
are simple, really- 16 bit latches connected to a R-2R resistor ladder and
a deglitcher (resistors are laser trimmed for accuracy).  Delta-sigma
DACs are pretty simple also- the neat thing is the way they can "push"
most of the quantisation noise into the ultrasonic, but that's a matter
of math, not complicated design.  The noise difference between 16 bit linear,
18 bit linear and delta-sigma occurs below 90 dB and the Multisound, which
has the best specs I've seen so far has a 91 dB S/N ratio.  Any time you
put your cards inside the computer, you're going to have a very hard time
getting over 90dB S/N, so DAC differences are the least of our worries.
Look at Ariel Corp. of New Jersey as an example.  They make DSP cards for
engineers for the Mac, PC and Suns.  Their bottom of the line cards have
ADCs and DACs on board with big metal shields around them and coax going
from the analog section to shielded jacks.  Everything else has a connector
for external boxes, like the ProPort (ADC, DAC) and DatPort (AES/EBU for
digital I/O to CD, DAT, etc.). 

Also, how good is your amp and how loud is your air conditioning vent?

Back to designing your next soundcard (ha!)-
Morgan
morganw@emu.com   woodson@cse.ucsc.edu    flames to /dev/null
call me if you have some insight into why people actually buy these
things- games only, is multimedia real, do people really do music
with soundcards & how can a GUS sound better w/1MB RAM???
408-438-4504 x213 E-Mu     408-454-0797 abode