The Sound Blaster Live! Book: A Complete Guide To The World`s

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1 The Sound Blaster Live! Book: A Complete Guide to the World's Most Popular Sound Card by Lars Ahlzen and Clarence Song ISBN:1886411735 No Starch Press © 2003 (572 pages) Open the door to a world of new sounds and unlimited potential for your Sound Blaster Live! Table of Contents The Sound Blaster Live! Book—A Complete Guide to the World’s Most Popular Sound Card Part 1 - Features & Basics Chapter 1 - The Evolution of Sound on the PC Chapter 2 - An Audio Primer Chapter 3 - The Sound Blaster Live! Hardware Part 2 - Connecting Peripherals Chapter 4 - Accessories Galore! Chapter 5 - Connecting Devices Chapter 6 - Speakers Part 3 - Fun Stuff Chapter 7 - The Mixer Chapter 8 - Eax Chapter 9 - Drivers and Other Tweaks Chapter 10 - Playing Games Chapter 11 - Watching Movies Part 4 - Creating Audio Chapter 12 - Creating A Music Library Chapter 13 - Recording Audio Part 5 - Composing Music Chapter 14 - Midi Explained Chapter 15 - Connecting Midi Instruments Chapter 16 - Introduction To Soundfonts Chapter 17 - Sequencer Basics Chapter 18 - The EMU10K1 Digital Audio Processor Appendix A - The Midi Specification Appendix B - The General Midi Sound Set Appendix C - The GS Sound Set Appendix D - The MT-32 Sound Set Appendix E - The Sound Blaster Live! MIDI Implementation Index List of Figures List of Tables List of Sidebars CD Content 1 2 The Sound Blaster Live! Book—A Complete Guide to the World’s Most Popular Sound Card Back Cover Creative’s Sound Blaster Live! Delivers features and performance surpassing professional audio equipment—if you know how to use it. No matter how experienced you are with the Live! Card, authors Lars Ahlzen and Clarence Song (the people behind the two most popular unofficial Live! Websites, “Live! Center” and “Alive!”) will show you how to get more out of your Live! Card and have fun doing it. Everything you need to know is here—from features and connections to creating audio and composing music, and a thorough discussion of the software included with the Live! Learn to: • Install and use digital I/O accessories like the Live!Drive for enhanced audio connectivity • Connect the Sound Blaster Live! to multimedia speakers and home theatre systems • Use the mixer and play with EAX (Environmental Audio Extensions) • Record audio, including mixer settings and audio editing basics • Use the card’s MIDI capabilities and connect MIDI instruments • Find, create, play, and manage SoundFonts • Use the sequencer, including MIDI, effects, and SoundFont support in Cakewalk and Cubase • Connect SBLive! Hardware (including the various connectors, jacks and digital input/output features) About the Authors Lars Ahlzen is the founder of the “Live! Center” website and a Computer Science and Engineering student at Chalmers University of Technology in Gothenburg, Sweden. Clarence Song is a software engineer living in Singapore, and an avid technology, multimedia, and AV enthusiast. He runs the poplar “Alive!—Sound Blaster Live! Resource” website. The Sound Blaster Live! Book—A Complete Guide to the World’s Most Popular Sound Card Lars Ahlzen, Clarence Song NO STARCH PRESS San Francisco Copyright © 2003 Lars Ahlzen and Clarence Song. All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. 1 2 3 4 5 6 7 8 9 10-06 05 04 03 No Starch Press and the No Starch Press logo are registered trademarks of No Starch Press, Inc. All Creative’s and its affiliated companies’ logos are registered trademarks or trademarks of Creative Technology, Ltd. and its affiliated companies. "Dolby," "Pro Logic," "Surround EX," and the double-D symbol are trademarks of Dolby Laboratories. Other product and company names mentioned herein may be the trademarks of their respective owners. Rather than use a trademark symbol with every occurrence of a trademarked name, we are using the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. 2 The Sound Blaster Live! Book—A Complete Guide to the World’s Most Popular Sound Card The Sound Blaster Live! Book—A Complete Guide to the World’s Most Popular Sound Card 3 Publisher: William Pollock Editorial Director: Karol Jurado Cover and Interior Design: Octopod Studios Composition: Octopod Studios Copyeditor: Judy Ziajka Proofreader: Stephanie Provines Indexer: Broccoli Information Management Distributed to the book trade in the United States by Publishers Group West, 1700 Fourth Street, Berkeley, CA 94710; phone: 800-788-3123; fax: 510-658-1834. Distributed to the book trade in Canada by Jacqueline Gross & Associates, Inc., One Atlantic Avenue, Suite 105, Toronto, Ontario M6K 3E7 Canada; phone: 416-531-6737; fax 416-531-4259. For information on translations or book distributors outside the United States, please see our distributors list in the back of this book or contact No Starch Press, Inc. directly: No Starch Press, Inc. 555 De Haro Street, Suite 250, San Francisco, CA 94107 phone: 415-863-9900; fax: 415-863-9950; [email protected]; http://www.nostarch.com The information in this book is distributed on an "As Is" basis, without warranty. While every precaution has been taken in the preparation of this work, neither the authors nor No Starch Press, Inc. shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in it. Library of Congress Cataloging-in-Publication Data Ahlzen, Lars. The Sound Blaster Live! Book : a complete guide to the world’s most popular sound card/Lars Ahlzen and Clarence Song. p. cm. Includes index. 1-886411-73-5 1..Expansion boards (Microcomputers 2. Computer sound processing. 3. Sound cards. 4. Computer music. I. Song, Clarence. II. Title. TK7895.E96 A34 2003 004.5’3–dc21 2002001658 The Sound Blaster Live! Book—A Complete Guide to the World’s Most Popular Sound Card 3 4 Part 1: Features & Basics About the Authors Lars Ahlzen is the founder of the "Live! Center" website (http://www.listen.to/sblive) and a Computer Science and Engineering student at Chalmers University of Technology in Gothenburg, Sweden. Clarence Song is a software engineer living in Singapore, and an avid technology, multimedia, and AV enthusiast. He runs the popular "ALive!—Sound Blaster Live! Resource" website. Acknowledgments This book would not be possible without Bill’s trust and confidence in offering us, first-time authors, the opportunity of a lifetime to write a book about something we enjoy. Our gratitude also goes out to Karol and everyone at No Starch Press, whose hard work has resulted in what you now hold in your hands. I wish to thank my family and friends for their patience and support during this busy phase of my life. I would also like to thank Anders Claesson, whose camera is responsible for many photos in the book, and everyone who has supported and contributed to my websites and my music. Last, but certainly not least, without Clarence’s great knowledge and attention to detail, this book would have been nowhere near what it has become. —Lars Ahlzen Thanks to my family, for their understanding and sacrifice when I could not be there. To Guoliang, for the constant encouragement and for graciously offering his help. To Cheng Kiang and Ee Siang, for getting me involved with the sound card. To Melvin, Mingwei, and Raymond, for your invaluable contributions. To Desmond and Jimmy, for making some of the photos in the book possible. And I am not forgetting my partner-in-crime, Lars—thank you for always being there! —Clarence Song The authors would also like to thank the representatives of these companies for their prompt assistance and for allowing us to feature their products: Michelle Fradette from Altec Lansing; Anne Khoo, Leslie Lee, Timothy Leong, and Linn Loh from Creative Technology for their support; Manal Ma and Kristen Stonecipher from CyberLink; Kristin Thomson from Digital Theater Systems; Kaleo Willess and Roger Dressler from Dolby Labs; Chris Douglass and Rob Read from Edirol; Hubert Winkler, author of Hubi’s LoopBack Device; Chris Cutter from InterVideo; Joshua Ryan Hall from Klipsch; Jamie O’Connell from MIDI-OX; Paul DiComo from Polk Audio; Paul Quinn from Quinnware; Paul McKnight from Really Effective Software; Alan Cheung from StudioAX; Gina Gaffney from Twelve Tone Systems; Roel de Wit from Utopia Sound Division; and David Harold from VideoLogic Systems. And, thanks to you for picking up a copy of this book! Part 1: Features & Basics Chapter 1: The Evolution of Sound on the PC Chapter 2: An Audio Primer Chapter 3: The Sound Blaster Live! Hardware 4 Part 1: Features & Basics Chapter 1: The Evolution of Sound on the PC 5 Chapter 1: The Evolution of Sound on the PC Download CD Content Overview Beep. That's all PCs could do before sound cards existed. The engineers and designers at IBM, where the PC was born, added a very simple tone generator that produced simple electrical waveforms that were channeled to a tiny speaker mounted on the PC casing. The beeper, as the PC speaker is affectionately called, is used to provide audio beep codes for diagnostic purposes and allow the PC to alert users to certain conditions. At that time, the PC was deemed a serious business machine, to be used for office applications such as word processing. After all, IBM stands for International Business Machines. Fortunately, processors that provide computing power in PCs were designed to be multipurpose and to process information for a wide variety of tasks. Naturally, the PC's potential as an entertainment machine helped it gain popularity in homes, and people quietly snuck games into their PCs at work. (Many games of that time had the all-important "boss key" feature. Or: When the boss walks in, a quick tap on the boss key, like the F5 key, and the game changes the screen to a mockup of some office application like a spreadsheet, and you'll seem to be hard at work!) Interactive entertainment such as games became a part of computing, and audio played a huge role in the effectiveness of such applications —definitely more so than spreadsheets. Even then, audio can also add value to business applications. For instance, a slide presentation can have far greater impact with the mere addition of audio and video clips. The beeper became woefully inadequate; something was needed to bring music and sound in PCs to the quality level of musical recordings and movie soundtracks. Music Cards Many enterprising companies came to the rescue by taking sound and music synthesizer chips found in electronic musical instruments and placing them on circuit boards that could be inserted into the expansion slot on a PC's motherboard. (We have to thank the designers of the PC for including such expansion capabilities!) These expansion cards were the precursor to the sound cards of today, and were termed music cards because of their capabilities derived from technology used in electronic musical instruments. Tip You can read more about music cards and game music in Chapter 10, "Playing Games." Music cards, like the popular AdLib card with its FM synthesizer, provided music generation capabilities that were characteristic of the technology available in the late 1980s and early 1990s. They offered a basic set of features for PCs to adequately produce music for games and other software: • Simple methods were used to simulate instrument sounds. This was crucial because processors and electronics were not very advanced like today, and if they had been, they would be too costly for a mass-market product like the PC. It was also not possible to play back real recorded instruments and sound because of the large storage space required, and also because memory chips were slow, expensive, and had limited capacity. This resulted in the use of electronically simulated audio derived from simple mathematical algorithms. The music resulting from such technology was often characterized as electronic sounding, tinny, and metallic—sounds really bad to most of us today, but at that time heavenly compared to the beeper. • Because music often relies on layering and harmony of different instruments and sounds, these electronic music generation techniques also provided the ability to play several instrument sounds Chapter 1: The Evolution of Sound on the PC 5 6 Chapter 1: The Evolution of Sound on the PC simultaneously to create a coherent piece of music. This "polyphonic" ability is a huge improvement from the monophonic PC speaker that could play only a single tone at a time. The AdLib synthesizer can play 11 basic FM instrument sounds at one time. • With this music generation hardware, small and manageable music files were possible. Small music files allowed games and other applications to communicate and send instructions to the card to produce music, without clogging up the tiny amount of communication bandwidth available between the PC and other components. With the popularity of music cards, many game developers saw the potential and added support for cards like the AdLib to further immerse players in their games. Many PC gamers and enthusiasts snapped up these cards from the stores to hear the exciting stereo and polyphonic soundtracks that give the PC the musical capabilities of video game systems from Nintendo and Sega. Music cards paved the way for sound cards in the PC and played a huge role in the success of the Sound Blaster. Tip Read more about the evolution of game music in Chapter 10, "Playing Games." Music cards also gave musicians a much better environment to write music by making it possible to compose and sequence music by looking at notes on the computer monitor, and freely change and shuffle them around. This form of music composition eventually evolved to the point today where computers can be used as full-fledged desktop music production tools that rival professional studio equipment costing tens of thousands of dollars. In fact, many music sequencing and digital audio editing workstations in studios today use high-end professional sound cards installed in the same Macs and PCs we find in our homes! Tip Find out more about how to use the Live! for music composition in Chapters 14 to 17. Sound in the Real World Despite technological limitations of early music cards, they adequately generated polyphonic music that sounded cohesive as a tune, though electronic-sounding; it still served its purpose for the games and electronic music applications of that time. However, the "real world" was still missing from these music cards, because they could not generate or playback sounds that occur around us. For instance, the complex waveforms of shattering glass could not be generated with a simple music card. It would be ideal if computers could also do what audio tapes and vinyl records can: by using recording equipment to capture the vibrations of the air that make up sound, storing that on media like tape, and reversing the process to translate the recorded sound stored on the media for playback on speakers. Because computers work with information in digital format with only two absolute values of 0 and 1, it was not straightforward to represent the minor graduations, as well as the widely differing components of analog audio. Several fundamental issues had to be addressed: • How to represent analog audio waveforms in digital 0s and 1s. • How to reliably capture and convert analog waveforms to a digital format. • How to store digital audio in various data storage media, including analog tapes, optical discs, and many other formats. • How to convert digital data back to analog waveforms that can be heard. • How to store and output audio that covers the entire hearing range of humans. • How to build such digital audio devices cheaply, so they can be included in consumer products like CD players and sound cards. The solution is now generally known as digital audio, and the predominant method of implementing this is through the use of digital-to-analog converters (DACs) and analog-to-digital converters (ADCs) that convert between digital and analog methods of representing sound. The sound provided by an audio source, such as a microphone, is captured in analog form and converted to digital 0s and 1s by the ADC. The reverse conversion is performed by the DAC, so that the original captured audio can be retrieved and played back. 6 Chapter 1: The Evolution of Sound on the PC Chapter 1: The Evolution of Sound on the PC 7 Just like the addition of sound to silent movies sparked off an artistic transformation in Hollywood, the invention of DACs and ADCs gave electronic equipment the ability to realistically capture and reproduce sound that occurs in the real world, ushering a brand-new aural dimension for audio equipment and sound cards. Tip The next chapter will delve more into the DAC and ADC process. The DAC and ADC are the most basic and essential components of any sound card, and remain so today, as they act as the bridge between the analog world of vibrations of air creating sound, and the digital world of 0s and 1s. They are used to play back MP3s, music, and sound effects recorded in games, and to allow recording from various audio sources like microphones and CDs. The Sound Blaster When introduced in 1989, the first Sound Blaster broke new ground by integrating the popular FM synthesizer found on the AdLib music card with the ability to record and play back digital audio—all at an affordable price. The significant improvement in audio over the PC speaker enticed enthusiasts and gamers. Soon, the sound card became an essential component in PCs, and Creative would make millions of Sound Blasters and become the sound card powerhouse that it is today. Figure 1.1: The very first Sound Blaster Chapter 1: The Evolution of Sound on the PC 7 8 Chapter 1: The Evolution of Sound on the PC Wave Audio The first Sound Blaster could manage only mono FM synthesis and 8-bit mono digital audio, resulting in sound that is close in quality to an AM radio. The Sound Blaster Pro added stereo to the FM synthesizer and Wave audio capability, making sound from the Sound Blaster produce stereophonic sound that can be differentiated by our two ears, like the predominantly stereo sound systems available. Games could play back sound effects with this capability; sounds like gunshots and the evil laughter of a boss character in a game could be effectively conveyed by playing back true-to-life recordings of such sounds. Many sound card owners also shared audio recorded in digital form, exchanging floppy diskettes or transferring Wave files over modems. The Sound Blaster 16 finally brought sound cards to the much-desired CD-quality audio benchmark with its 16-bit, 44.1-kHz ADC and DAC. With the increase in the number of bits used to store digital audio, recorded sounds became much smoother and more realistic compared to the electronic-sounding nature of 8-bit audio. The Sound Blaster Live! has the maximum sampling rate improved from 44.1 kHz to 48 kHz, increasing the number of times that "snap-shots" of the audio are taken and stored, thereby increasing the detail of the resulting digital audio recording. 48 kHz is also commonly used in consumer digital audio technologies like DVD. Today, sound cards like the Live! can reproduce clear and crisp audio that covers the full range of sound that can be heard by humans. The quality of DACs used are much better than older Sound Blasters, because of better sound card design, advancements in electronics, and improved manufacturing processes. This ended the age-old complaint of Sound Blasters making "computer bleeps," hisses and noises in the speakers, and lets the Live! work admirably with high-end speakers and sound systems. The patented 8-point interpolation of the EMU10K1, the audio chip used in all Live! cards, helps smooth out lower-quality Wave audio files that are less than the preferred 16-bit 44.1 or 48 kHz format, making them sound clearer than other sound cards. Many programs like audio streamed over the Internet, and sound effects of the majority of games today still use Wave audio that is around 16-bit 22 kHz, which is half the quality of audio CDs. Unlike earlier Sound Blasters that could play only a single Wave file at a time, the Live! can mix and play back many Wave audio channels simultaneously, thanks to hardware Wave mixing built into the EMU10K1. There can be many audio applications playing Wave audio, and the Live! will output all of them at the same time. Contrast this to sound cards of the past, where the first application that manages to grab hold of the sound card gets exclusive use of the DACs, and subsequent applications that need to play Wave audio will be rejected. Although this capability seems useless at first, it has its benefits. For instance, you wouldn't want to miss out on an alarm from your scheduler or the alert sound from an instant messenger just because MP3s are playing in the background. Audio Sample CD Folder: Chapter 1 – The Evolution of Sound on the PC File: Sample Size Comparison.wav Listen to the sound quality of the same piece of music, first recorded from a sound card in 8-bit mode, and compare it with the 16-bit version that follows. You'll notice that the 8-bit version is less able to store a detailed representation of the original audio, especially in the higher frequencies, because less space is used to store the digital audio information. We have included the orginal files as Sample Size Comparison 8-bit.wav and Sample Size Comparison - 16-bit.wav, so that you can hear how much better the 8-bit file sounds on the Live! compared to the older sound card we recorded from. 8 Chapter 1: The Evolution of Sound on the PC Chapter 1: The Evolution of Sound on the PC 9 Music Synthesis The early Sound Blaster cards, including the Sound Blaster AWE cards, all had the electronic-sounding FM synthesizer based on the Yamaha OPL2, and later the OPL3 FM synthesizer chips. This form of music generation was essential in the early days when PC hardware was not as advanced and affordable as today, where streaming a large prerecorded piece of music from an audio file to the Wave out-put is common. Wave Audio for Music? Of course, playing back prerecorded music through the DAC would enable the sound card to reproduce audio as it was recorded, just like a consumer CD player using its built-in DACs to play back Wave audio data read from the compact disc. This method called "streaming audio" negates the need for a music synthesizer on the sound card. However, storage space was scarce in the early days, especially before the CD-ROM emerged as a viable storage medium. Even then, the constant transfer of data from the CD-ROM to the sound card required a significant amount of CPU power, which was little compared to the multi-gigahertz processors available today. In games, it was unwise to spend a large percentage of this power just to play back a music track in the background when a less costly option was available, especially because CPU power can be put to better use to perform other operations that can enhance game play, for example, to produce dazzling on-screen graphics and effects, and to perform artificial intelligence computation for more realistic computer-controlled opponents. Despite the lack of realism, the music synthesizer was essential to sound cards in those days, as it offloads much of the chore of generating music away from the CPU. Note Composers writing music for synthesizers use the musical instrument digital interface (MIDI) format, where only the instructions on which notes to play, which instruments to use, and how long to play them are stored. No actual audio recordings and instrument sounds are stored in MIDI files, making them small, manageable, and easy on PC resources. Realistic Instruments with Wavetable Synthesis Naturally, people wanted the realism of music produced by sound cards improved, but at the time, only costly high-end electronic music equipment had the hardware necessary to generate music that sounded very close to real-life musical instruments. It was not until the Sound Blaster AWE cards released in 1996 that Creative provided a more realistic form of music generation called wavetable synthesis, right on the sound card. The wavetable synthesizer in the AWE cards utilized E-MU's expertise in wavetable technology to produce the cost-effective EMU8000 synthesizer chip. Audio Sample CD Folder: Chapter 1 – The Evolution of Sound on the PC Files: FM synthesis.wav and Wavetable synthesis.wav Listen to the instruments generated by the Sound Blaster 16's FM synthesizer and compare it to the wavetable synthesizer of the Live! Although the same MIDI file was used to record both audio samples, they sound significantly different because MIDI stores information only on the notes to be played back. Therefore the realism of the music depends on the technology employed in the music synthesizer hardware on the sound card. This is also true with the professional synthesizers used in studios, because they also rely on the MIDI standard. Instead of mathematically generating instruments with techniques like FM synthesis, wavetable synthesis stores actual recordings of Wave audio of instrument sounds, which can then be manipulated by the wavetable synthesizer to produce music. This feature is carried on in the EMU10K1 chip found on all Live! cards, with even better wavetable sound quality and effects. Chapter 1: The Evolution of Sound on the PC 9 10 Chapter 1: The Evolution of Sound on the PC Note Unlike the EMU10K1 on the Live! which handles both Wave audio and wavetable music synthesis, the EMU8000 chip on the AWE series handled only music synthesis, and similar to the Sound Blaster 16, used a separate set of ADCs and DACs for Wave audio. Affordable Music Composition The Sound Blaster is popularly known as a multimedia and gaming sound card, especially the Live!, with its vaunted EAX technology for games. However, do not be surprised when someone tells you that the Live! is a very capable music-making tool, as well. Since the Sound Blaster AWE cards, many musicians have turned to the Sound Blaster as an affordable means of composing music—some of which has even been used in commercial recordings. In addition to the wavetable synthesizer in the Sound Blaster AWE32, Creative threw another advancement into the mix that made the Sound Blaster ideal for musicians: SoundFont technology. Like typographic fonts used for screen display and printing with operating systems and word processors, SoundFonts are files that contain custom instrument sounds. They can be loaded on any Sound Blaster that has SoundFont support, and subsequently are used in MIDI compositions as regular instrument sounds. Tip Find out more about SoundFonts in Chapter 16. Such capabilities were already available to professional musicians and studios, but these devices, called samplers, cost thousands of dollars. With this sampling feature available on Sound Blaster AWE and Sound Blaster 32 cards using the EMU8000 synthesizer chip, and on the EMU10K1 chip found on the Live! cards, the Sound Blaster becomes an affordable sampler, which costs a few hundred dollars compared to the thousands of dollars for professional samplers. They can also render these compositions as Wave audio to be compressed to MP3 or even mastered to CD audio discs. Note Most of the Sound Blaster cards that use chips from E-MU can support SoundFonts, like the EMU8000 and EMU8008 used on many Sound Blaster cards, the EMU10K1 on the Live! and even the EMU8710 chip used in a previous E-MU product that puts a sound card inside a small PC card to be used in notebooks. The faster peripheral component interconnect (PCI) connection between the Live! and the PC allow SoundFonts to be loaded into the main system memory. By using the main system memory, users can easily add more RAM to their PCs to load many SoundFonts at the same time and load SoundFonts that are large and contain many instrument sounds. Instead of being limited to the meager half-megabyte of SoundFont RAM built into most Sound Blaster AWE cards, the Live! can use up to 32 MB of your PC's memory to load SoundFonts. The Live! also adds features such as higher-quality effects processing, Sound-Font and wavetable synthesis, and 8-point interpolation to keep the instrument sounds smooth and realistic when manipulated by the wavetable synthesizer. The polyphony, which determines the number of instrument sounds that can be generated simultaneously by the music synthesizer, has been increased from 32 in the earlier EMU8000 Sound Blasters to 64 in the Live! to allow more complex instrument sounds and SoundFonts to be layered in a composition. The Sound Card as an Audio Hub With sound cards, faster video cards, and the emergence of the CD-ROM as an economical storage medium, multimedia quickly became a buzzword for PCs. These computers could play smooth video and high-quality audio and allow interactivity in games, educational software, and even business presentations. With the development of hardware such as CD-ROM drives, MPEG and DVD decoders, telephony cards, and other devices that need to output sound to the speakers, the sound card had to evolve from a simple Wave audio and music synthesizer combination to an audio hub supporting many of these capabilities: • Provide connectors to accept sound from all these different hardware peripherals. • Mix all the different sound sources together and send them to speakers connected to the sound card. • Allow individual volume, mute, and balance controls for each sound source. 10 Chapter 1: The Evolution of Sound on the PC Chapter 1: The Evolution of Sound on the PC 11 • Allow the user to balance the volume of each source and control the overall volume. • Facilitate Wave recording from any of these sources. The mixer is the nucleus for consolidating the myriad of sound sources together on the sound card. Earlier sound cards used analog mixers that were prone to hiss and noise, because the sound card had to be connected to the motherboard inside the PC, which is an electrically noisy environment. Newer sound cards like the Live! make use of a digital mixer and tightly integrated electronics that reduce the possibility of noise affecting the sound that is sent to the speaker outputs behind the sound card. Tip Read more about the Live! card's mixer in Chapter 7. Chapter 4, "Accessories," will cover the extension connector found on every Live! card. The extension connector gives Live! owners the flexibility to add more inputs and outputs on the Live! by connecting it to digital I/O devices like Creative's Live!Drive and other third-party digital I/O cards. You can connect CD players, MiniDisc recorders, microphones, VCRs, satellite and cable receivers, DVD players, and other analog or digital audio equipment to the Live! to record and play back sound, making the Live! the center of a PC-based home entertainment system. Tip Chapter 5, "Connecting Devices," will illustrate how to connect audio and audio-visual equipment to the Live! and an attached digital I/O device. The Sound Blaster Creative has come a long way since the first Sound Blaster was launched more than a decade ago. In the early days, the company faced strong competition from other companies who relentlessly made "Sound Blaster-compatible" sound cards, threatening to seize the crown from Creative. However, Creative was able to stave off much of the competition and remain at the top of the PC sound card market for over a decade. The company is constantly innovating and adding features to sound cards to improve sound quality and realism, with the ultimate aim of providing effective and affordable audio solutions for PCs to attain Hollywood-quality audio. A Timeline of the Sound Blaster Family So many models of Sound Blaster cards have been released that many Creative staff, not to mention the general public, can barely keep track of them! The following is an overview of some of the more significant developments in the evolution of the Sound Blaster, leading up to the Sound Blaster Live!, affirmed by many users and publications as a revolution in PC audio. Before the Sound Blaster, Creative made a card called Game Blaster. It used a simple 12-voice music synthesizer dubbed the Creative Music System (C/MS), and was aimed at gamers who wanted better and yet affordable music for their games. It had some support from a few developers but did not gain widespread acceptance compared to the huge support for the AdLib card and its FM synthesizer. It also did not have Wave playback capability, which, thankfully, the Sound Blaster had. 1989 Sound Blaster The first sound card was launched with 8-bit mono Wave audio and FM synthesis. The first version, simply called the Sound Blaster 1.0, also had Creative Music System (C/MS) stereo music synthesizer chips to retain compatibility with Creative's Game Blaster music card released in 1987. However, this feature was removed in subsequent 1.5 and 2.0 versions to save cost, since the AdLib-compatible FM synthesis on the sound card sounded better (even though it was mono compared to C/MS's stereo) and had excellent support in software and games. Future Sound Blasters do not have C/MS. Chapter 1: The Evolution of Sound on the PC 11 12 Chapter 1: The Evolution of Sound on the PC 1991 Sound Blaster Pro With the great success of the Sound Blaster, Creative took the next logical step by adding stereo for both parts of the sound card—the 8-bit Wave audio and FM synthesis. This year also marked the beginning of the multimedia revolution, with CD-ROMs and multimedia upgrade kits gaining in popularity, especially with home PC users. Creative jumped in the fray by retailing upgrade kits consisting of a Sound Blaster and a CD-ROM drive. 1992 Sound Blaster 16, Sound Blaster 16 ASP, and Wave Blaster Creative brings the Sound Blaster to CD-quality level, with support for 16-bit, 44.1-kHz digital audio recording and playback. The music generation portion of the sound card continued to use FM synthesis. The first version of the card was the more advanced Sound Blaster 16 ASP (Advanced Signal Processor; later renamed the CSP, for Creative Signal Processor), which had a simple processor that could apply algorithms to Wave audio. It was initially used for QSound 3D positioning and acceleration of voice recognition, but developer support for the ASP was not strong. In addition, including the chip in all sound cards was costly, so this feature is not found most Sound Blaster 16 and future generations of Sound Blaster cards. Around this time, the Plug-n-Play standard was adopted by the market to allow PC peripherals to be easily configured without requiring users to fiddle with switches on the hardware, like having to move little plastic jumper caps on the Sound Blaster's circuit board. Creative introduced new versions of the Sound Blaster cards and tagged on a "PnP" behind their names to signify Plug-n-Play compatibility, like the Sound Blaster 16 PnP. Multimedia became a hot buzzword and was the must-have for enthusiasts and gamers. Before CD-ROM drives were able to work with the standard hard drive connections found on all motherboards, early CD-ROM drives had their own connection standards. PCs did not come with connectors for these various CD-ROM standards, and it was up to the sound card to provide a controller so that the CD-ROM drive could communicate and send data to the PC. To allow the Sound Blaster to be affordably used with CD-ROM drives in multimedia upgrade kits and new PCs, CD-ROM controllers were added to the Sound Blaster cards for the most popular CD-ROM drives from Mitsumi, Panasonic, and Sony. A Sound Blaster 16 MultiCD was also sold that supported all three CD-ROM interfaces, and a Sound Blaster 16 SCSI-2 supported CD-ROM drives with SCSI connectors. As wavetable synthesis became more affordable, Creative added a 26-pin wavetable connector at the top of some Sound Blaster 16 cards so that daughter-boards like Creative's Wave Blaster, Roland's excellent SCD-10 and SCD-15, and Yamaha's DB50XG could be attached to the sound card. These wavetable upgrade cards provided more realistic music from MIDI files and games. The Wave Blaster had 4 MB of instrument samples and used wavetable technology based on the professional synthesizers made by E-MU, a manufacturer of 12 Chapter 1: The Evolution of Sound on the PC Chapter 1: The Evolution of Sound on the PC 13 electronic musical equipment used in music and movie studios around the world. This partnership would lead to Creative's subsequent acquisition of E-MU and the use of its expertise in the development of audio chips for future Sound Blasters, including the EMU8000 and the EMU10K1 used in the Live! Budget versions with fewer features—for instance, no wavetable connector—these were sold under the "Value" name, like the widely used Sound Blaster 16 Value. This strategy allowed the Sound Blaster 16 to penetrate the OEM and budget segments of the market, providing an affordable sound card for PC manufacturers to bundle with their PCs. Many older PCs still use the Sound Blaster 16. 1994 Sound Blaster AWE32, Vibra Pro, and Vibra 16 With rising consumer awareness of the increase in quality provided by wavetable synthesis, and the popularity of wavetable sound cards like the affordable Gravis Ultrasound, Creative introduced the Sound Blaster Advanced WavEffects (AWE) sound cards based on the EMU8000 synthesizer chip. These cards had 1 MB of instrument samples stored in ROM and 512 KB of RAM for uploading custom SoundFonts. There are two empty memory slots on the sound card, allowing it to use up to a maximum of 28 MB of SoundFont memory by adding 30-pin SIMM memory modules also used in PCs at that time. Vienna SoundFont Studio was released several months later to give musicians the ability to create their own instrument samples for the AWE32. Instead of moving to a brand-new sound card design, Creative retained Sound Blaster 16 compatibility in the AWE32, including the old FM synthesis chips. This allowed software and games to slowly transition to this new wavetable capability, which developers quickly warmed up to, supporting the EMU8000 in their software. The 32-note polyphony of the wavetable synthesizer in the EMU8000 allowed it to play back 32 instrument sounds at the same time. Consumers often mistook the AWE32 for a 32-bit sound card because of the number 32. Unlike the 16 in Sound Blaster 16 referring to the bits supported by the Wave audio's DAC, the AWE cards referred to the polyphony of the EMU8000 wavetable music synthesizer and not the Wave audio portion of the sound card. (In those days, bits were attributed to performance, just like the number of megahertz is a big selling point today and is significant in marketing and public perception of the power of PC hardware.) Creative also introduced the Vibra Pro and Vibra 16 chips based on the Sound Blaster Pro and Sound Blaster 16, respectively. Unlike the Sound Blaster cards, which required many chips to make (for instance, one for ADC/DAC and another for the FM synthesizer), the Vibra integrated all the essential features of a Sound Blaster into a single chip. This drove down manufacturing costs and allowed the chip to be used on motherboards as a built-in audio solution, negating the need for a sound card. Some affordable Sound Blaster cards were also made with this chipset. Chapter 1: The Evolution of Sound on the PC 13 14 Chapter 1: The Evolution of Sound on the PC 1995 Wave Blaster II An upgrade to the Wave Blaster was introduced. The Wave Blaster II used the EMU8000 chip with 2-MB ROM of instrument sounds. This gave owners of Sound Blaster 16 cards with the wavetable connector the ability to upgrade to wavetable synthesis similar in quality to the one found in the AWE cards. 1996 Sound Blaster AWE64 and Sound Blaster AWE64 Gold Despite the name and marketing efforts, the AWE64 was still a minor upgrade from the AWE32 and is definitely not a 64-bit sound card. (It is still capable of only 16-bit Wave audio.) The 32-note polyphonic EMU8000 chip remained in the AWE64. The quoted 64-note polyphony comes from a Sondius WaveGuide software synthesizer that relied on the CPU instead of the EMU8000 to produce the extra 32 notes of polyphony, and only for selected instruments. SoundFont worked only with the hardware synthesizer chip and not the software synthesizer, so in effect, the AWE64 has the same features as an AWE32. On the AWE64, the SIMM memory slots were removed and replaced with a proprietary memory slot that required users to purchase a Creative memory upgrade module to add more SoundFont RAM. The Sound Blaster AWE64 Gold was marketed as a high-end audio solution and came with RCA instead of mini-jack outputs, an S/PDIF output bracket for digital connectivity, and brass-colored connectors. SoundFont 2.0 was introduced, and added several features to the popular SoundFont standard that is still in use today in the Live! 1997 Sound Blaster AWE64 Value, Sound Blaster AWE64D (OEM), EMU8008, and Vibra 16x The EMU8008 and Vibra 16x audio chips were introduced as upgrades to their older counterparts, providing new features like 3D stereo enhancement and full-duplex Wave audio. Internet use exploded and videoconferencing, Internet telephony, and "voice over IP" were hot applications of this global communications network. Full-duplex support in the sound card was needed to let users speak into a microphone and hear the other party simultaneously, and also to use different playback and recording sampling rates at the same time. To provide this feature cheaply, Creative updated the Windows drivers of older Sound Blaster cards to simulate full duplex by quickly switching between recording and playback modes, while future Sound Blasters would have full duplex as a standard feature, implemented in the sound card's hardware. Permutations of the EMU8000-based cards like the Sound Blaster 32 and Sound Blaster 64 were introduced without the 512 KB of SoundFont RAM. This made sense because most applications do not use the SoundFont RAM (except for the minority that compose music with SoundFonts). Other cards like the Sound Blaster AWE64 Value and Sound Blaster AWE64D (OEM) were also introduced to target budget customers and the OEM markets, respectively. The year also saw Creative acquire Ensoniq for its PCI sound card and Sound Blaster emulation technology, which permitted sound cards using the PCI connector on the motherboard to work like all the older Sound Blaster cards that use the much slower industry standard architecture (ISA) connection. Like E-MU, Ensoniq has its roots in professional synthesizers and electronic musical equipment. This acquisition led to the introduction of a new range of PCI-based Sound Blasters in the following year, aptly called the Sound Blaster PCI platform. At the end of the year, Creative showcased the EMU10K1 at Comdex Fall and outlined the strategy for more advanced effects and audio processing for a new line of Sound Blaster cards that would be introduced less than a year later as the Sound Blaster Live! 14 Chapter 1: The Evolution of Sound on the PC Chapter 1: The Evolution of Sound on the PC 15 By this time, motherboards had support for CD-ROM drives and the onboard CD-ROM controllers on sound cards were not necessary. Subsequent PCI-based Sound Blasters including the Sound Blaster PCI and Live! would have the controllers removed. The wavetable connectors were also removed in these sound cards. 1998 Sound Blasters based on Ensoniq AudioPCI, Sound Blaster Live!, and Sound Blaster Live! Value At the beginning of the year, Creative adapted and sold Audio PCI sound cards brought over from newly acquired subsidiary Ensoniq under the Sound Blaster brand name, resulting in products like the Sound Blaster PCI 64. This was widely seen as an interim measure to quickly get the Sound Blaster to the PCI platform, as many other low-cost PCI sound cards appeared on the market with features better than those of the dated EMU8000 sound cards. In September, Creative officially launched the Sound Blaster Live! and the EMU10K1 as the next-generation platform for Sound Blaster cards. The marketing tagline, "So Real It Has to Be Live!," highlighted the ability to add reverberation and effects to any audio played back by the sound card. This feature was known as Environmental Audio. Creative also heavily promoted Environmental Audio eXtensions (EAX) to game developers as a quick and easy way to add Environmental Audio to games. EAX, together with the support for surround sound with four-channel speakers and DirectSound3D positioning, would make the Sound Blaster Live! one of the most popular gaming sound cards for the next three years. The audio quality of the wavetable synthesizer was improved over the EMU8000 cards, and the faster PCI connection allowed the removal of costly memory chips that had to be included in EMU8000 cards for SoundFont support. Now, SoundFonts are stored in the memory of the PC and obtained directly by the wavetable synthesizer in the EMU10K1 when needed. A full version of the product known simply as the Sound Blaster Live! was marketed alongside the Sound Blaster Live! Value, which was an affordable version with fewer connectivity options, but otherwise retained all the features and sound quality of the full Live! product. A much more affordable US$99 compared to the full product's US$299, helped the Live! penetrate the market and garner a wide installed base. The new features and huge leap in audio quality offered by the Live! gave many PC users an incentive to upgrade their sound cards. 1999 Sound Blaster AudioPCI 128, Sound Blaster Live! Platinum, Sound Blaster Live! Player, Sound Blaster Live! MP3+, and Sound Blaster Live! X-Gamer February saw the number of Sound Blaster Live! cards hit the one million mark, while in November, Creative announced that the total number of Sound Blaster cards reached 100 million units—just in time for the tenth anniversary of the Sound Blaster. The lower-end sound cards based on the Ensoniq AudioPCI design continued to be sold in retail and OEM markets to be included in new PCs, while the Live! does its rounds in the retail channel as well as bundled with some new high-end multimedia PCs from popular PC manufacturers. Live!Ware 2 and 3 were released to the public. These software upgrades added new functionality to the Live! They included better 3D positioning algorithms, new utility applications such as the Surround Mixer, and more features for users to customize the effects of the Live! EAX quickly became a standard supported by many game developers, and Microsoft licensed EAX for inclusion in DirectX used by Windows games and multimedia applications. EAX 2.0 was added to support occlusion and obstructions, allowing games to simulate muffling of sound when blocked by objects in the gaming environment. EAX 3.0 was also announced at the same time to counter the popularity of competitor Aureal's A3D 2.0 3D audio rendering technology. Unfortunately, EAX 3.0 was never released. Chapter 1: The Evolution of Sound on the PC 15 16 Chapter 1: The Evolution of Sound on the PC In September, the Sound Blaster Live! cards were upgraded with a digital out-put that supported digital speakers from Creative's speaker subsidiary, Cambridge SoundWorks. The Sound Blaster Live! product line was diversified to reflect the different software bundles available. The X-Gamer bundle included the same second-generation Live! card with EAX game titles, while the MP3+ cashed in on the popularity of MP3s with applications and tools for digital music. The new Platinum product had a wide-ranging software bundle, but most importantly, the new Live!Drive was bundled to add more analog and digital inputs and outputs for greater connectivity. 2000 Sound Blaster Live! 5.1 series Environmental Audio Graphical Librarian Editor (EAGLE), a graphical 3D audio modeling software to easily add EAX and 3D audio, was introduced to the game development community. Creative built on the success of the Live! with the Sound Blaster Live! 5.1 series of cards. The product diversification and naming convention remained similar to those of the second-generation products introduced in 1999, including the X-Gamer, MP3+, and Platinum. The Live! 5.1 added another analog center/woofer output to the existing front and rear outputs, allowing the sound card to be connected to 5.1 speaker systems and home theater receivers. The new Live!Drive included in the 5.1 Platinum product was a new model called the Live!Drive IR that had IR remote control capability. Dolby Digital decoding became a standard feature and made the Live! 5.1 an affordable solution for watching DVDs on the PC with the full impact of 5.1 surround sound. Advancements in the Sound Blaster Live! The Live! was an advancement from the older Sound Blaster cards, but among the new features that were introduced, two of them stand out. These features proved to be very popular and became essential in sound cards today. Effects Processing Echoes and reverberations occur all around us. Shouting in a hollow tunnel will produce eerily long, repeating echoes. A choir performing in a concert hall will not sound majestic or grand when you move it to your bedroom, as the reflection of sound waves provided by the architecture of the concert hall is gone. Reverberation and echoes are key to realism, and are often employed in movie soundtracks, to add ambience to vocals, as well as augment musical instruments in audio recordings. Effects processing allow electronic devices to simulate these repeating echoes. Other interesting things can also be done to audio, like the imaginative use of pitch-shifting effects (known technically as a "vocoder" effect) to make Cher's vocals in her hit single, "Believe," out of the ordinary. Effects processing requires significant processing power, and it was only after the mid-1990s that it moved out of professional recording studio equipment and into consumer sound cards like the Sound Blaster AWE series. Earlier sound cards had limited ability to add reverb and other effects to music generated by a wavetable synthesizer, but the Live! is the first mass-market sound card to provide effects processing not only on wavetable synthesis, but also all other sounds including Wave audio and audio from external audio devices connected to the Live! It definitely sounds much better than the primitive echo controls on cheap karaoke systems. In fact, many musicians attest to the quality of the effects processing in the Live! The EMU10K1's built-in effects processor handles this feature, providing the flexibility to place sounds in any environment and allow pitch shifting, muffling, and other interesting effects to be applied to Wave audio and music. Creative markets the effects processing of the Live! as Environmental Audio and Environmental Audio eXtensions (EAX), and they were successful in garnering support from game developers, as well as recognition from consumers. With effects processing, sound cards can now simulate different realistic 16 Chapter 1: The Evolution of Sound on the PC Chapter 1: The Evolution of Sound on the PC 17 environments—especially useful for first-person games like Unreal! Note Visit your local gaming store, and you'll probably find a lot of game packaging with the EAX logo imprinted alongside other logos like the ubiquitous Windows logo. Tip Chapter 8, "EAX," will tell you more about EAX on the Live! and show you how to use the driver utilities to change or create your own environments. 3D Audio Sound can emanate from any direction, but audio systems and sound cards have largely been limited to the two-speaker stereo format for decades. The use of surround sound in movies and home theater helps to underscore the benefits of surround sound. When playing first-person games where you explore an environment, it would be advantageous for the game's sound effects to clue you in about the direction of every event occurring in the game world. When 3D positioning is used, players can hear sounds from all directions—even from behind. This gives gamers a strategic advantage, since telling the direction of an opponent would be less of a chore, unlike plain stereo-sound cues that place all the sound in front of the player even when it is supposed to come from behind. Note The Live! uses virtual 3D surround when it is placed in two-speaker mode and games with 3D audio are played. Before the Live! was introduced, some sound cards tried to provide virtual 3D surround algorithms that made use of two speakers to simulate sound behind the listener, but that was not particularly realistic for many because of the need to stay in the same sweet spot from the speakers for the virtual algorithms to be effective. A few sound cards supported more than the usual two-speaker stereo configuration, including Creative's own Sound Blaster PCI 64, but it was the Live! that popularized the use of 3D audio and four-speaker setups for PCs, which Creative calls a "four-point surround" configuration. Together with affordable multichannel speakers from subsidiary Cambridge SoundWorks, Creative successfully converted many PC enthusiasts and gamers to multi-speaker configurations. It wasn't difficult to convince gamers and developers alike, because the benefits of 3D audio are readily apparent! Today, 3D audio support in every sound card is a must, especially for serious gamers. The Past and Present Creative's history is synonymous with the evolution of sound cards on the PC. Several factors contributed to this, including tactics used on the technical and legal fronts to keep the competition at bay. Factors that helped make Creative a success today were the foresight by the founders that a sound card is a great device for the PC and the vision to put sound cards in every PC. Also, as you have seen in the timeline and the many other Creative products, the company has a willingness to try new things and innovate, while most of the early competition merely copied and made cheaper "Sound Blaster–compatible" sound cards. Sound Blaster Compatibility One of the things that helped Creative and the Sound Blaster maintain dominance for such a long time is definitely Sound Blaster compatibility, which stemmed from the hardware and software architecture of early PCs. You may have seen in promotional material, news articles, and reviews that proclaim the Sound Blaster as the "de facto standard" for sound cards, especially before 1996 when DOS games were predominant. This meant that a Sound Blaster–compatible sound card supports all the features of, and works in a way similar to, an original Sound Blaster card. This was important for DOS games because of the proliferation of Sound Blaster cards and the abundance of software (mainly games) that support the Sound Blaster. Developers could write code to support and use the features of the Sound Blaster; they did not have worry about supporting many different sound cards that did not conform to an established standard. Windows changed things. With a driver layer and hardware abstraction, Windows acts as an arbitrator, requiring all instructions and requests sent to the hardware (for example, requests to print information to the Chapter 1: The Evolution of Sound on the PC 17 18 Chapter 1: The Evolution of Sound on the PC screen or play back audio on a sound card) to be sent to Windows first. It then communicates these instructions sent from the applications to the hardware using the drivers provided by the hardware manufacturer. Windows drivers are required for any hardware peripheral that wants to operate with Windows and its software. With this abstraction provided by Windows, Sound Blaster compatibility is moot. Sound card manufacturers can use their own designs and need not implement Sound Blaster compatibility. As long as a sound card has functioning Windows drivers, Windows applications can use the sound card. Previous cards up to the Sound Blaster AWE series still had Sound Blaster compatibility, as many games were still using DOS and relied on the Sound Blaster as an audio platform. It was not until the Sound Blaster PCI cards, including the Live!, that Creative moved away from Sound Blaster compatibility in hardware. Instead, Creative opted to include software emulation so that some (but not all) older DOS games can still work in Windows 95 and 98. Today, we seldom hear the term Sound Blaster compatible. Rightly so, the focus has shifted to audio features like surround sound, effects, and 3D audio support in games. The Future With an illustrious history in the PC audio market, Creative is not immune to changes in the marketplace. Competition is still strong, especially when more affordable sound cards providing similar features than the Live! are available at lower prices. Audio is becoming an essential part of computing. Today, every notebook and many personal digital assistants (PDAs) come with built-in audio. In desktop PCs, sound chips on many motherboards threaten to encroach on the sound card business. The Motherboard Threat In the past few years, the sound card has become ubiquitous in the PC, prompting Intel and motherboard manufacturers to cater for sound chips right on the motherboard. This motivation is mirrored in the integration of video chips on motherboards as an affordable replacement for graphic cards, because every PC needs a display output. The motherboard is a vital component for every PC to function, and it acts as an arbitrator and hub between all the various components used to make up a PC, like the CPU, graphic cards, hard drives, USB ports, and all other peripherals. Figure 1.2: Audio connectors on a motherboard Some motherboards today come with non-Creative sound chips, which are adequate for normal use, especially in office PCs where bells and whistles like multispeaker support and effects processing are unnecessary and may even affect productivity. When the initiative to embed sound on the motherboard was announced by Intel in the late 1990s, many predicted the death of Creative's sound card business. The company has proven critics wrong and that sound cards still have room to grow with new high end features that promise to enhance audio. In the coming years, we'll be watching how Creative innovates to provide better audio products for games and entertainment on the PC, and continues developing products with features that surpass those in the increasingly sophisticated audio chips used on motherboards. 18 Chapter 1: The Evolution of Sound on the PC Chapter 2: An Audio Primer 19 The Future of PC Audio PC audio will remain an important and essential part of computing, with applications for games, the Internet, audio, videoconferencing, voice mail, movies, MP3s, and many other purposes. The Sound Blaster Live! played an important role in the evolution of PC audio, especially in improving gaming audio, and promoting multichannel speaker systems for PCs. Newer sound cards are poised to continue this advancement, as more powerful audio technologies emerge. One day, the audio from your PC may sound so true to life that you'd think it was something real! That's exciting to look forward to. Chapter 2: An Audio Primer Download CD Content Sound is an interesting phenomenon caused by the mere movement of air. They come in many forms—from the subtle whiff of a breeze, the jarring sound of thunder, to the rhythmic blending of musical instruments in music. Many of us do not pay attention to it like we do with our visual senses. Most would notice that a movie has great scenery, balanced lighting, and good-looking actors, and that a game has dazzling 3D graphics and special effects. However, many would not notice or comment that a movie or game has an effective and enveloping soundtrack, or notice that the audio quality was subpar. And still, sound has the power to move us in unimaginable ways. How is it that the mere movement of air can do so much and provide such a wide range of sounds for our ears to feast on? This chapter delves into the more technical aspects of audio, but avoids going into details that only engineers would understand. We hope this chapter will give you an idea of how analog sound occurs in our world and how digital audio has changed and improved the way we can record, use, and manipulate sound. How We Hear Sound Part of the reason why audio affects us in profound ways is that our ears are linked closely to our brains, giving music and sound the power to affect us greatly. Even though to many of us, this may seem abstract and difficult to comprehend at times, we can still enjoy and appreciate the music and great audio quality produced by our sound cards and audio systems. It's All About Vibrations Sound is nothing but vibrations of the air. Every time an object moves and pushes against the air, it creates compressions and rarefactions, or differences in air pressure, which we perceive as sound. Unlike most matter in our physical world, air can be easily compressed and moved about, allowing it to act as a medium to transmit sound from one place to another. Compressions and rarefactions create sound waves, which are propagated in all directions from the object. The different way in which each object vibrates the air results in a seemingly unlimited palette of sounds that inhabit our world, from animal noises to earth-shaking explosions. Chapter 2: An Audio Primer 19 20 Chapter 2: An Audio Primer Figure 2.1: Sound waves Note The speed with which sound waves are propagated in the air is relatively low compared to light waves. This is why you can hear echoes when you speak in a relatively small empty room, but you never see a delay when you move in front of a mirror. While depending a little bit on conditions such as temperature and air pressure, the speed of sound (in air) is approximately 340 meters per second (1,110 feet per second). For instance, when you speak, your vocal cords excite the air around you and cause neighboring air particles to vibrate in a similar manner. This process continues until the air hits something, like the eardrums of a person nearby. In the ear, the sound and vibrations are further transmitted via a few small bones (the hammer, anvil, and stirrup) to the elements in the ear that are sensitive. These elements pick up the minute vibrations of the air and transmit nerve impulses to your brain, creating different thoughts and sensations. Sound as Waves Compressions and rarefactions of the air can be captured rapidly at equal intervals of time and represented on equipment such as an oscilloscope. The graph on the oscilloscope would show a continuously evolving plot or line that moves up and down in tandem with the increase and decrease of air pressure. These are known as sound waves. A common measure of sound waves is frequency. Many sounds are repetitive in nature, like a sustained note on a flute, the repetitive chugging of an engine, or even when you open your mouth and say "aaaaa" for the doctor. The sound waves produced are relatively consistent and occur at equal intervals of time, resulting in a reasonably steady frequency in the waveform. Frequency Frequency measures the number of vibrations per second of the sound and is represented in hertz (often abbreviated as Hz). If, for example, something (let's say a speaker cone) is vibrating back and forth 85 times a second, we say that it produces an 85-Hz tone. Different elements in the ear are sensitive to different frequencies. Altogether, the human ear can hear sound with frequencies in the range of about 20 Hz to 20,000 Hz (or 20 kHz). The lower frequencies, called bass, are deep and rumbling like those of an earthquake, while the higher frequencies, known as treble, can be very sharp and ear-piercing, like a cymbal or glass breaking. There are more elements in the ear that are sensitive to mid-range frequencies between 200 and 2,000 Hz. Therefore a 500-Hz tone will sound louder than a 50-Hz tone with the same intensity. Note Frequencies below the hearing range of 20 Hz are known as subsonic, and those above 20 kHz are known as ultrasonic. Dogs can hear frequencies up to 67 kHz, which is much higher than humans can hear. Imagine the myriad of high-pitched sounds that they have to contend with every day. Dog whistles don't seem to make any sound but work miraculously! Figure 2.2: Two pure tones as they are usually represented on paper, on an oscilloscope, or a computer screen. The amplitude is pictured on the vertical (y) axis, and the time on the horizontal (x) axis. The right waveform has twice the frequency (twice as many compressions and rarefactions per second) as the left one, but only 20 Chapter 2: An Audio Primer