From sklar@nes.nersc.gov Thu Apr 15 23:09:51 1993 Return-Path: Received: from osi-west.es.net by picasso.ocis.temple.edu (NeXT-1.0 (From Sendmail 5.52)/25) id AA17318; Thu, 15 Apr 93 23:09:50 EDT Received: from nes.nersc.gov by osi-west.es.net with SMTP (PP) id <04207-0@osi-west.es.net>; Thu, 15 Apr 1993 20:09:20 +0000 Received: by nes.nersc.gov (5.61/CRI-7.4) id AA92467; Thu, 15 Apr 93 20:09:19 -0700 From: David Sklar Message-Id: <9304160309.AA92467@nes.nersc.gov> Subject: no subject (file transmission) To: sklar@picasso.ocis.temple.edu Date: Thu, 15 Apr 93 20:09:18 PDT X-Mailer: ELM [version 2.3 PL2] Status: OR Date: Mon, 25 Jan 93 1:03:24 EST From: dionf@ERE.UMontreal.CA (Francois Dion) Message-Id: <9301250603.AA26790@brise.ERE.UMontreal.CA> Subject: Franky in 3D To: Ultrasound Daily Digest Well, i think it's time i put my grain of salt on the 3d mania. First of all, even if it is a bit long, i suggest to read it all. And if you dont want to wait for a 3D driver for the GUS, dont forget to read one of my other post in this digest with the subject: Franky in suround. Now, on with the show: There are several systems that are in use to get 3D sounds on recordings and some have been around since the 50s. Now i wont go into the "how it works" of the more recent ones, but i think this will clear up some confusion. The first part is a "hands-on" experiment, the second is informations, including the address and phone of the owner of the technology that is used with the Gravis Ultrasound. Let's get back to the early days of stereo. One record company (i cant seem to remember) was pushing it, while another (again, blank. anyone?) competed. Interestingly enough, technological development was put on stereo, and not on the first 3D system which was called "binaural recording" and it simply consisted of two microphones placed like the ears. You can try it this way: Go to a hat store and buy an extruded foam mannequin head. You'll then need two microphones. Condenser will do, but you will need to power them if you want to use them with the GUS, since it take a dynamic microphone because it does not supply phantom power like some mixer with XLR plugs. I will post a circuit later for Radio-shack condenser mike unit (a small element that cost about 2$) if there is some interest. If you dont want to mess with that, go with a cardiod dynamic element. Note that sensitive enough cardiod will cost you a lot, so think about that. You cut holes in the ears of the head, to insert the microphone units (dont forget to make the wires of the elements go inside the head and out the rear (or wherever). Use glue to fill the crack around the mic. Also, the more the ears look like real ears, the better it will work. If you trim the foam, dont forget to use an hairdryer to soften it (it will be more uniform). That's it. Try recording sounds, and you'll be surprised. I was! I did the experiment with a polystyrene head on which i incrusted two PZM microphones. Now that you understand how 3D recording is nothing like stereo recording, we'll see what is accesible presently. First, the gadget we just built in the previous section exist commercially, and is called "Mikey" and is made by Spherical Sound. It's the only system commercialised where the microphones are placed in a head. Another system is made by Virtual Audio and claims to enhance stereo depth, but is not labeled 3D audio. I dont have much more info on it, but from the description it looks like the same thing as the "mikey". Two other systems use less restraining microphones situation and can also be used on any signal because a DSP simulate a 3D signal from parameters entered on the machine. QSound (no hyphen) was developped in Quebec, and the inventor sold the concept to another company (Archer it seems). It is not that good even with electrostatic headphones, and is pretty bad if you are listening to it thru speakers and you are not in the soft spot. And for trivia: Madonna, Sting, Wilson Phillips and Paula Abdul to name a few have used the QSound on their latest recordings. Another trivia: The Q logo is very very close to Hydro-Quebec logo... QSound cost around 18K$ and is not midi controllable. The other variant with a DSP is Roland RSS (Roland Sound Space). It is a bit better (depending on how it is used) than QSound with headphones, but suffers the same faith as QSound when you are listening with speakers. Just move a bit from the soft spot, and suddenly what was in front left is now back left. RSS was used on Suzanne Cianni _Hotel Luna_ album. RSS cost around 40K$ and is midi controllable. Another system on which i have zero information is called Audio Cybernetics. The last technology is called Focal Point 3D Audio. It was developped by Bo Gehring and first used on the Macintosh computers with a modified Audiomedia (Digidesign). It cost around 1400$ in this configuration. But, Gravis saw that (Focal Point is from Seattle) and it is the system that we will be getting. At a much better price. The system produce the sounds with these parameters: direction, elevation and distance. I am pretty sure that Gravis will have to develop a SYSEX command set. We already need it badly, but with 3D, i will shoot myself if i cant control it thru sysex. Hope i've entertained you... Ciao, -- Francois Dion ' _ _ _ CISM (_) (_) _) FM Montreal , Canada Email: CISM@ERE.UMontreal.CA (_) / . _) 10000 Watts Telephone no: (514) 343-7511 _______________________________________________________________________________ Audio-C-DJ-Fractals-Future-Label-Multimedia-Music-Radio-Rave-Video-VR-Volvo-... ------------------------------ Date: Mon, 25 Jan 93 1:06:29 EST From: dionf@ERE.UMontreal.CA (Francois Dion) Message-Id: <9301250606.AA26886@brise.ERE.UMontreal.CA> Subject: Franky in 3D forgot... To: Ultrasound Daily Digest I forgot: Focal Point(tm) 3D audio 1402 Pine av., #127 Niagara Falls, NY 14301 Voice/fax: 1-416-963-9188 Ciao, -- Francois Dion ' _ _ _ CISM (_) (_) _) FM Montreal , Canada Email: CISM@ERE.UMontreal.CA (_) / . _) 10000 Watts Telephone no: (514) 343-7511 _______________________________________________________________________________ Audio-C-DJ-Fractals-Future-Label-Multimedia-Music-Radio-Rave-Video-VR-Volvo-... From sklar@nes.nersc.gov Thu Apr 15 23:10:08 1993 Return-Path: Received: from osi-west.es.net by picasso.ocis.temple.edu (NeXT-1.0 (From Sendmail 5.52)/25) id AA17331; Thu, 15 Apr 93 23:10:07 EDT Received: from nes.nersc.gov by osi-west.es.net with SMTP (PP) id <04212-0@osi-west.es.net>; Thu, 15 Apr 1993 20:09:34 +0000 Received: by nes.nersc.gov (5.61/CRI-7.4) id AA92487; Thu, 15 Apr 93 20:09:33 -0700 From: David Sklar Message-Id: <9304160309.AA92487@nes.nersc.gov> Subject: no subject (file transmission) To: sklar@picasso.ocis.temple.edu Date: Thu, 15 Apr 93 20:09:33 PDT X-Mailer: ELM [version 2.3 PL2] Status: OR Date: Mon, 25 Jan 93 1:39:20 EST From: dionf@ERE.UMontreal.CA (Francois Dion) Message-Id: <9301250639.AA27136@brise.ERE.UMontreal.CA> Subject: Franky in surround To: Ultrasound Daily Digest Ok, you have read the 3D thing, and you cant wait. You want big sound. The only possibility for now is surround. Now surround cost a lot of money, and it will not be useable anymore once you get the 3D driver. Wrong. Now, i hope you have an amplifier, cause if you dont, you cant use this little hack to get surrounding sound. WARNING: i am not responsible for any damage resulting from the use or misuse or anything else related to this circuit. Check that your - posts are connected to ground and not the +. If it's the case reverse the connections to the amplifier. It works surprisingly well considering the cost. Have fun! | Amplifier | | + - - + | You connect the front speakers as usual (dont mixup /| | | |\ the polarities!) _ | |_| |_| | FLS: Front left speaker (/_\) | /_\ /_\ | FRS: Front right speaker | FLS FRS | R: variable pot 50 ohm. 10 watts or more (depends on |_ _| the amplifier) > | | < ><'R R'>< RLS: Rear left speaker (use a much smaller speaker > < for rear than front. 8 ohm also.) | RLS RRS | RRS: Rear right speaker (") | _ _ | | \_/ \_/ | the 2 - on front speakers are connected to the |_/ \_._/ \_| ground of the amplifier internally, so you dont + -|- + have to connect them. |_ > | ><'R > Here, you do need to connect the 2 - thru R to the _|_ amplifier ground. - AMP GND Put the 3 potentiometer in a box so that you have the control in one place, and use enough wire so you can move with it. You'll have to experiment so that the R going to ground is a little higher than the other 2 and once that adjusment made, the other two must be adjusted so that the rear speakers are just adding a touch of depth (if you turn them off, you notice that the surround is gone). Also, if you have A-B speaker selection, plug the rear speakers on the + of B instead of A, you will then be able to switch them off easily. Of course, when you will use the 3D audio, it will affect the signal, so it's better to unplug the rear section. But for your video, tape, CD and regular GUS, you will still find it cool. Ciao, -- Francois Dion ' _ _ _ CISM (_) (_) _) FM Montreal , Canada Email: CISM@ERE.UMontreal.CA (_) / . _) 10000 Watts Telephone no: (514) 343-7511 _______________________________________________________________________________ Audio-C-DJ-Fractals-Future-Label-Multimedia-Music-Radio-Rave-Video-VR-Volvo-... From sklar@nes.nersc.gov Thu Apr 15 23:10:32 1993 Return-Path: Received: from osi-west.es.net by picasso.ocis.temple.edu (NeXT-1.0 (From Sendmail 5.52)/25) id AA17339; Thu, 15 Apr 93 23:10:24 EDT Received: from nes.nersc.gov by osi-west.es.net with SMTP (PP) id <04220-0@osi-west.es.net>; Thu, 15 Apr 1993 20:10:04 +0000 Received: by nes.nersc.gov (5.61/CRI-7.4) id AA92603; Thu, 15 Apr 93 20:10:03 -0700 From: David Sklar Message-Id: <9304160310.AA92603@nes.nersc.gov> Subject: no subject (file transmission) To: sklar@picasso.ocis.temple.edu Date: Thu, 15 Apr 93 20:10:03 PDT X-Mailer: ELM [version 2.3 PL2] Status: O Gravis Ultrasound audio synthesis --------------------------------- (update 1) It is easier to find the Holy Grail than to find a text describing precisely what synthesis method the GUS uses, so it's time i take a shot at it. For this text i have searched thru ftp archives troughout the world, have asked info from Ensoniq, Roland, TurtleBeach, Advanced Gravis, Forte Creative Labs and i also took into account the numerous comments, praise and flames i received to model the text. Since this text is a result of a collective internet and industry wisdom, flames will go the way of /dev/nul. And please, read the text carefully, because i have received some comments from people who were thinking i wrote something when in fact i wrote the opposite (particularly from non anglophones). You probably have heard about the GUS beeing a wavetable soundcard. I have received some comments that the GUS is not such a thing, but since the industry uses this term (i.e. CL waveblaster, GUS, TB multisound etc...), i am not in a position to create confusion by renaming the technology. Wavetable explains perfectly what it is. A table containing a waveform. The GUS uses the third generation of wavetable synthesis, so before i start explaining it, i'll talk about the first two generations first. The first generation of wavetable synthesis was actually a _digitally_ controlled _analog_ oscillator(s) where parameters controlling the waveform were kept in memory. The curtis based synths and some others are directly derived from this concept. The second generation of wavetable synthesis uses a digital oscillator, with the waveform held in memory in it's basic form (one period usually). Parameters to alter the oscillator behaviour are also in memory. I use the general term "memory" instead of RAM, because in some case it's actually ROM, FlashROM, PROM, EPROM, switches, buffers etc... The Ensoniq chip found in the Macintosh Plus is an example (8 bit, 4 oscillators, 4096 byte wavetable). The third generation of wavetable synthesis which can be found in two flavors (RAM or ROM) is based on the second generation, but uses bigger wavetables to hold the waveform (either in single period or multi period format) including this time the attack and release. In this section, i will focus only on the GUS implementation, which basically encompass all other implementations. Basically, what you have are 32 oscillators which can do the exact same thing, and be programmed separately and/or simultaneously. What the hardware can do without the operating system is not too important here since we are looking at what the GUS _can_presently_do_ (with modifications to the OS, the GUS could do pretty much any synthesis method one can dream up), not what it would have done if the OS wasn't available. Of course, more processing done in hardware means more CPU cycles left for other things. So in the GUS, you have some RAM (up to 1Mb) that holds 1, 2, 3, etc, wavetables which consist of a sampled (or soft-synthesised) waveform, some parameters and optionally a sampled attack and release. The GF1 chip (an asic based on the Ensoniq DOC-II chip) will then playback a waveform when triggered based on some parameters it is given, and on others it will fetch from the wavetable. I dont know if all parameters can be fetched from RAM by the GF1, nor if the GF1 can fetch some instructions from RAM, but by using the current OS built in the windows drivers or in the DOS library, this is what the GUS _can_presently_use_ to synthesise music: - sampled or envelopped attack in 8/16 bit, signed/unsigned format * - sampled waveform (anything! a period, or a several seconds sample) * - sampled or envelopped release * with: - velocity (volume) * - panning (balance) * - precise frequency playback rates (with frequency based antialiasing and oversampling) * - mixing of all the channels * Up to here, it's sample playback. But there is more: - full vibrato (FM, depth, rate, sweep) - full tremolo (AM, depth, rate, sweep) - LFO (Low Frequency Oscillator) * - forward, reverse, dual direction looping or no looping * - the loop points can be anywhere (for sampled attack and release) * |-------|-------------|--------------| Start Start loop End loop End - 6 point enveloppe - tuning * - fractional endpoint * - combination of oscillators (up to 4 if the GF1 implementation is the same as Ensoniq) * - previous waveform usage * And more recently: - 3D (focal point 3D positioning) * indicates that the operation is done in hardware. Some others may be done in hardware but i have not done any tests or found any technical information to confirm it. I also base 1 item on the DOC II capability, which should be implemented in the GF1. Also, reverb, flanger, phasing etc... could be easily implemente within the drivers. Presently it can be done with a little work on the patches and/or midi timestamp (i have succesfully made flanger and phasing). Another thing that could be implemented is dynamic patch loading since the card supports it (i have done it). You can even get a distorted sound (ideal for guitars, vox, analog synths) by simply changing the 2's complement flag (work best with soft-synthesised patches). Last, it is far better to have a RAM wavetable synth than a ROM one, since you can upload your samples. Even sound canvas owners (and other synths too) complain that their ROM based GS synth lacks interesting drum and bass sounds, cannot play sound effects, and is not usable for dance and techno. Also you can have more space for each samples, because you always have only the samples you need in memory, so you can have better sampling rates and better waveforms. Ciao, -- Francois Dion ' _ _ _ CISM (_) (_) _) FM Montreal , Canada Email: CISM@ERE.UMontreal.CA (_) / . _) 10000 Watts Telephone no: (514) 343-7511 _______________________________________________________________________________ Audio-C-DJ-Fractals-Future-Label-Multimedia-Music-Radio-Rave-Video-VR-Volvo-...