DOLBY SURROUND AT WIRED 95 A text for musicians and sound-engine coders... Please read an important note about soundcards at the end of this text. Wired'95 will be the next party in Belgium, organized by Antares, Imphobia and some members of TFL-TDV, like me... It will take place in the city of Mons, in the university rooms, from the 3rd to the 5th of november. I would tell you about the sound equipement that will be used in the comporoom(s) : kind of Dolby Surround system with 3 speakers (min. 1000W each) + subwoofers on the screen side for classical stereo, and -at least- 10 mid-power speakers all around the room (back and side) for surround effects. The comporoom will be a big lecture hall, with confortable seats and ama- zing projection screen (see Wired 94 reports in Imphobia 9). Some people have written last year that Wired 94 projection room had the best quality of pic- ture ever seen at a party ! My wish for this year is that people say the same thing about sound. So I rely on you, music makers, to make stuffs that will exploit it the best way ! Here are some advices to make your work sound even greater on it: -Try not to play every sample just on the left or right channel but use also center or -better- most panning position between full left and full right. There are two reason for that. First: there will be a third speaker for center. So even people who are sitting on the side of the hall can hear sounds coming from the center of the screen. Second: full left and full right sounds are also reproduced by surround speakers, but less loudly than surround effects. It means that, even if you don't use surround in your song, there will be a distinction between the front and rear speakers. Only the center sounds are coming only from the screen; the others are coming from everywhere in the room -with a domination of left or right. -How to make surround effects in your modules ? You can of course use the ProTracker surround command, but no player could play it on GUS. Only MOD and AMS have that command anyway (I heard that it was 8FF but it doesn't seems to work !?). The best way is to use two samples like this: One sample must be EXACTLY the same than the other one, but negated. (no surround command needed) Œ .. Sample #1 Œ Sample #2 I . . . I . I=====.=.=.=> I=====.=.=.==> I . I . . . I I .. Your ears won't hear the difference between those samples, but if you play them exactly at the same time, one full-left and the other one full right, you will get the REAL surround effect. With a Dolby processor or with the system that will be used at Wired95, they will be heard from the rear spea- kers (= surround speakers) ! Of course it takes a bit more memory, but the result is so good , even if you do not have a surround system at home to ear it ! Physically, one sample is negated in relation to the other one. You can do this with the "negate" function of many editors (that's not the signed/ unsigned function ! ) or write a very simple program to do it. I personnaly do apply a volume of -100% on the whole sample with FT2 (you can do this then save the sample and load it with ST3, of course, but don't forget the " PC <> Amiga " conversion then !). There is just a little problem with this method : If you play your module on a mono card, the result of playing both samples on the same -and only- channel will be... no sample heard. If you make a stand-alone module for the multichannel competition, that's not a real problem, because I don't think that mono-card owners are big module listeners. If you make your module for a demo, you can do like me: I reserve one or two tracks for surround FXs. One of both samples used to make it is al- ways on a "surround" track. So, when the demo detects an old mono card, it just has to mute this -those- track(s), and only one sample will be played so there will be no problem. You can also say : " Fuck mono card owners, they won't hear some samples, that's all !", It's easier, of course. - Don't use surround for "extreme-bass" sounds (like those you could use to make the seats vibrate :-) ), because in a "normal" 2-speakers stereo system, the negation of low frequencies do happen in the air. This means that you could loose some bass. - AESTETICS OF SURROUND. As the word "surround" says, it is more made for ambiance sounds than for rear effects like spaceships heard in your back, etc. One proof of this is that the surround effects are always less bright than front effects. Anyway, it is always funny to make sounds pass from rear to front of the room :-)... PROBLEMS WITH SOUNDCARDS ------------------------ The PC used for the demo/intro compo projection will have both GUS and SB16 soundcards. Your demo can use any of them. For the music compos , GUS will normally be used, but you can ask us to play your module on SB16. This para- graph explains some reasons of such a request: When you play the same sample on 2 channels on a GUS, there is always a short delay between the two voices. It is too short to ear a real "echo", but it can modify the sonority of that sample (especially with FT2, because with it the delay is can vary ...). It is quite a problem for making surround like I've explained upper : if you try to play the inverted samples on L & R chan- nels with a GUS, they won't overlap exactely. If you put your amplifier in mono mode, you should normally not ear those 2 samples (as I've explained upper...), But on a GUS , there will be a bright residual sound. More the delay is long, more the residue is loud. If the residue sounds nearly like the original sample, it means that the delay is so long that both samples don't overlap properly and the surround effect should be poor. It depends of the player, in fact, and maybe of the computer. So, IF YOU'VE MADE YOUR MODULE WITH A SOUND BLASTER PRO OR SB16, and... - if your module plays the same sample, with the same pitch, and at the same time on 2 different tracks, - if you use stereo samples, - if you make surround, you should better listen to it on a GUS (on a DX2-66 if you can) before the party, with the player that we will use (see last invitation file), so if you don't like the way it sounds, you could ask us to play it on SB16. Well, that's all for the moment, I hope you will be a lot of musicians and audiophiles at Wired 95 because I did the maximum to make you enjoy the compos ! You can contact me if you have any questions about anything. "Magic" Fred /TFL-TDV Wired 95 organizer responsible of sound Email: llardin@is1.vub.ac.be (leave "4Fred" as comment) Phone: +32-2-3747442 ask for Fred (French or English) Snail: Fr‚d‚ric Scalliet 53 Dieweg 1180 Brussels Belgium