High-end audio for multimedia environments.
Frequently, sound for a multimedia computer is treated as afterthought, using cheap, "tinny" -- sounding speakers. Even worse is the built-in speaker of most computers, barely adequate for occasional beeps. Yet "hearing" is one of our most powerful senses. Sound provides a high density of information and a rich set of attributes that strongly complement the visual elements.
Furthermore, sound, properly used, in many cases can add as much (or more) drama, emotion and information to a presentation as the visual aspects. (To test this assertion, compare watching a TV program with the sound off to watching it with the sound on. In most instances, more information is actually contained in the audio than in the picture.) It is not surprising, therefore, that education, training and other presentation environments using multimedia computers can be greatly enhanced by paying careful attention to the sound-reproducing elements in the systems. This article primarily focuses on that which delivers the audio to our ears-speakers.
* Software and Audio Cards
In a computer-based multimedia environment, sound reproduction mainly depends on three components: software, a sound card and self-powered speakers. (Though sound card outputs can be run through regular amplifiers and speakers, in all but large auditoriums it is much less complicated, cumbersome and costly to use self-powered speakers.) While the focus of this article is on such speakers, the following observations about software and sound cards will help the reader better understand the full environment.
Software: Early educational software just used beeps, buzzes and primitive musical note sequences for emphasis. However, some current educational software as well as most programs now in production include more sophisticated audio components.
Sound is becoming particularly important where animation and full-motion video are included in the content. Software drivers are available to support various emerging industry standards. Furthermore, the integration of CD formats into a multimedia presentation offers the possibility of an extremely high-quality audio component. This, of course, is also true when VCR-based video is included in the package.
Sound Cards: Low-end sound cards (like the original Sound Blaster from Creative Labs) typically use an 8-bit format, which restricts the quality of the audio that can be generated from software. Technologically superior 16-bit sound cards (Sound Blaster 16) offer much higher quality sound output.
Furthermore, some software (mostly games presently, but undoubtedly to become more prominent in the education and presentation sectors) is capable of also driving MIDI sound cards. These are able to generate literally hundreds of high-quality synthesized or sampled musical sounds, thus providing full symphonic/orchestral reproductions of music passages. Two leading vendors of MIDI technology are Roland (with the SCC-1 and RAP-10 GS boards) and Yamaha (with the CBX 301 system).
A multimedia computer user may also use the CD-ROM drive to play music CDs directly through the sound card and speakers while performing some other non-related function on the computer. Noteworthy, too, is Yamaha's CBX-T3 module, which integrates a sound card into an external package that can be used with computers via the serial port. This enables even notebook computers to support quality sound for external self-powered speakers.
* Categories of Self-Powered Speakers
The dramatic increase in interest for multimedia systems in the past two years has resulted in a flood of self-powered speakers. Most are relatively small, low-powered and inexpensive (under $100 list price). While such products may reproduce tolerable sound for games at home, truly highquality sound will generally cost considerably more--particularly if it is powerful enough for group presentations typical in education and training.
The focus of this article is on the higher end of the quality spectrum (without getting into auditorium size and audiophile quality). Most self-powered speaker systems can be classified into three categories: Stand-alone units; two-piece, integrated stereo systems; and three-piece, integrated subwoofer/satellite systems.
Stand-Alone Units: Speakers in this category have a built-in power supply, amplifier and the same controls on every unit. This permits a single speaker to be used in some applications, or they can be used in pairs to achieve a balanced, stereo soundstage. Examples of products in this category include the Roland MA-20 and MA-12C, Acoustic Research (AR) Powered Partner 570, and Yamaha MS101-II and MS202-II.
This category includes the most powerful components reported in this article. While stand-alone speakers have a great deal of flexibility, they are sometimes inconvenient to use. For example, each unit must be switched on and off separately, and volume and tone controls are individually adjusted on each speaker.
Integrated Stereo Systems: Speakers in this category have a single set of controls similar to a stereo system and typically have the power supply and amplifiers concentrated into one of the speaker cabinets, with a matching satellite speaker fed from the base unit. Examples of this two-piece speaker type include the AppleDesign, Bose RoomMate, and Yamaha YST-M10 systems. Controls on these units are integrated so that, for example, the volume adjustment controls both speakers simultaneously.
Three-Piece, Integrated Subwoofer/Satellite Systems: These systems take advantage of the fact that low bass frequencies are non-directional. A large, powerful bass woofer/driver is mounted in a separate cabinet that can be placed under a desk or other out-of-the way place. The highly directional mid- and high-frequency sound spectrum is reproduced by a pair of "satellite" speakers placed on each side of the listening area. Typically, the power supply and amplifiers are located in the sub-woofer cabinet, though the controls may be located either on the sub-woofer cabinet (like the AR Powered Partner 622, Sony SRS D2KPC and Bose Acoustimass Multimedia systems) or on the satellite units (like the Altec Lansing ACS 300).
A three-piece system is currently the state-of-the-art for audio in a multimedia environment. The satellite speakers create an effective, high-quality stereo soundstage, while the powerful non-directional subwoofer unit adds a rich bass that can actually be felt at higher volume levels. While the three-piece design may be a bit awkward when moving the speakers, the satellite units are relatively small, taking up little desktop space or they can be easily mounted on the wall for larger presentation rooms. Also, the separate bass driver can be independently located in a corner and against walls, positioned so as to achieve low-frequency reinforcement.
Due to these features, the quality of audio from these systems is far superior to that of stand-alone or conventional two-piece integrated stereo units of comparable size and price.
* What to Look For in Speakers
Multimedia applications will often require speakers to be placed adjacent to computer equipment, particularly disk drives and monitors. Thus any speaker chosen for computer applications must have proper magnetic shielding. All of the speakers mentioned in this article claim to have such shielding (except the sub-woofer unit in all three-piece systems; the satellites are shielded, but not the sub-woofer).
While each multimedia application may have unique requirements, the following criteria are generally considered important for deciding which system to acquire:
* Number and Types of Inputs;
* Control Characteristics Integration, Flexibility and Location);
* Sound Quality (Speech vs. Music); and
* Volume Requirements (Size of Room and/or Audience).
The following reviews the important issues with respect to each of these criteria.
Inputs: All self-powered speakers are designed to accept line level inputs, which means that they can be driven by most pre-amplified sources--CD-ROM and tape drives, computer sound cards, VCRs, portable "Walkman"-style CD and tape players, and many other sources. In general this excludes non pre-amplified inputs, such as microphones and record players.
In many environments it is desirable to mix signals from two sources, like voice and MIDI sound. While this can be done with virtually any speakers by using an external sound mixer, products from Altec Lansing (ACS 300), Bose (Acoustimass Multimedia), Roland (MA-20, MA-12), Apple (Design) and Yamaha (MS101-II, MS202-II) have this capability built into their systems.
Another desirable mixing feature is the ability to combine an audio program source (eg. from the computer) with microphone input (eg. from the instructor). Only the Roland (MA-20, MA-12) and Yamaha (MS101-II, MS202-II) products have this capability built in.
Sony's SRS D2KPC has RCA plugs for two line-level inputs but only allows them to be switched, not mixed. While this is very convenient for some applications, it does not provide true mixing. Note also that only the Roland, Altec Lansing and Yamaha systems have controls for adjusting the balance among the multiple inputs. The other systems that permit mixing will merely accept signals at the same relative volume as their input sources.
Finally, if only a single line-level input is needed, then any of the speakers described will satisfy this criterion.
Outputs: The AppleDesign System includes a headphone jack that silences the speakers when headphones are plugged in. This is a very nice feature and suits many instructional settings, such as environments in which several people are working; headphones avoid "crosstalk." Also noteworthy is the line-out feature on the Yamaha MS series. This permits passing the sound signal on to other units in special situations.
* Control Characteristics & More
The primary issues for controls are:
* Degree of Integration;
* System Flexibility; and
* Position or Location.
Integration: Stand-alone units do not integrate the controls; all volume, tone and mixing adjustments must be done separately and on both speakers, with careful attention paid to balancing so that the sound is uniform. While this is inconvenient, it does not inhibit the ultimate sound characteristics.
In contrast, integrated stereo systems and three-piece systems do have integrated controls. One knob exists for each of the principle functions (volume, balance, treble, bass, and line mixing where applicable), and controls all speakers.
Flexibility: Flexibility refers to the control features supported. Generally this would include at least an on/off and volume control. (Altec Lansing's ACS 300 is the exception, probably assuming it will be plugged into a switched master control unit. Ed note: See Update Sidebar.
Tone controls are absent on the less-expensive units (such as the Yamaha YST-M10 and the AppleDesign); a single tone or "loudness" (bass-booster; not volume) control is included on systems in the mid-price range (Sony SRS D2KPC and Roland MA-20, MA-12 and MA-7); both treble and bass controls are on the higher-priced systems (Altec Lansing ACS 300, Bose Acoustimass, AR Powered Partner 570 and 622, and Yamaha MS101-II and MS202-II).
Individual mike and line-level controls are featured on Roland's stand-alone units, whereas a single integrated two-line mixing control is on the Altec Lansing ACS 300. The ACS 300 also has a DSP (digital signal processor), which allows different sound environments, like a night club, concert hall, etc. to be simulated.
Location of Controls: Where controls are located is an issue only for three-piece systems because they may be either on the satellite units or on the sub-woofer component. (On the other self-powered speakers, controls are, of course, located on the speaker itself.)
In some situations it is more convenient to have the controls on the satellite units (like the ASC 300). This would be preferred if the satellite units are easily accessible, while the sub-woofer is not. In other installations, it may be preferable to have the controls on the bass unit--for example, if the satellites are mounted high on a classroom wall and difficult to reach. The Sony SRS D2KPC, AR Powered Partner 622 and Bose Acoustimass have the controls on the bass unit.
Sound Quality: Most systems mentioned here have very good sound quality at reasonable volume levels. Virtually all provide excellent voice projection and satisfactory music reproduction. The major differences between systems will be noticed in program material with a heavy musical component. Without question, of the systems reviewed for this article, all of the three-piece systems have music-reproducing capability superior to any of the other systems. Particularly, the AR Powered Partner 622, Altec Lansing ACS 300 and Bose Acoustimass systems, which are quite comparable, have the overall best sound quality. All three are a delight to listen to and have remarkable quality considering their size and cost.
Power Requirements: Obviously, sound-level requirements differ significantly depending on the size and sound absorption characteristics of the presentation space. Naturally, a single-user multimedia computer can be adequately serviced by a lower-powered system (like AppleDesign and Yamaha YST-M10) than is needed in a classroom; a standard room, in turn, requires less power than a larger one.
Of the systems described here, the AR Powered Partner 570 is the most powerful (35 watts/speaker); it also has very clear, undistorted sound. The Roland MA-20 and MA-12 are near the same category (15 watts/speaker and 10 watts/speaker respectively); and while they are somewhat lower in power they are much richer in flexibility due to a multiple-source input mixing capability.
All of the three-piece systems are capable of producing quite loud sound levels, though the Sony SRS D2KPC (4 watts per satellite and 11 watts for the subwoofer) will begin showing severe distortion at a lower volume level than the other three-piece systems.
Size: Virtually all of the "two-piece" systems require more desk space than the three-piece systems (which actually have very small satellites that fit nicely onto a crowded desktop, though one must find a suitable place for the subwoofer). Also, the satellite speakers in three-piece systems generally can be mounted on the wall or ceiling with relative ease.
Contrast this with a more conventional two-piece system: Since the bass driver is in the same cabinet with the other speakers, the units are larger, competing for desktop space or requiring significantly more substantial hardware for wall or ceiling mounting.
* Product Comparisons
Table 1 (on page 89) compares the features for 13 high-end systems with list prices ranging from $150 to $700. (Ed. note: This article was completed in April 1994; more speakers from the same manufacturers, as well as new companies, have since debuted; see Update sidebar.)
The old adage, "You get what you pay for," generally applies, though every one of these products produce a very acceptable sound. the most expensive product, the Yamaha MS202-II, allows for the most number of mixed inputs and is quite flexible. However, we would rate the Roland MA 20P to be the most flexible of all the products, because each of the three mixed inputs (microphone plus two line inputs) has its own level control.
If sound quality is the most important consideration, then any of the three-piece systems will far exceed the performance of the two-piece systems. The Bose Acoustimass Multimedia ($699) is a relatively new entry to the market and produces stunning sound quality. In an actual class of 60 people at Brigham Young University, students were literally "blown away" by the remarkable sound of this Bose system.
However, the Altec Lansing ACS 300 ($399) and AR Powered Partner 622 ($349) are also extremely impressive products that compete very well in sound quality at more moderate prices. The ACS 300 particularly has a very rich midrange with multiple-input capability and a full range of controls.
The simplest system to use is the Bose RoomMate, which has Only one control, volume, and boasts a very smooth sound.
Virtually all education, training and presentation systems of the future will use multimedia in some form. Next to high-quality color graphics, high-quality sound is the most significant media element for adding information to the environment.
This article, hopefully, has provided readers with a basic understanding of the issues involved in sound system selection and the features found on available products. Use these guidelines, then get ready to enjoy the exciting new dimensions of quality sound in the multimedia arena!
Lynn McKell is a professor of Accounting and Information Systems in the Marriott School of Management at Brigham Young University. His experience includes the development and presentation of CAI course support and multimedia educational seminars using interactive satellite technology for IBM. Prior to entering teaching, McKell was an electrical engincer member of technical staff at Bell Telephone Laboratories where his work resulted in his patent for the primary circuitry of the touch-tone dial. His combined electrical engineering and information systems background provides unique technical expertise for the authorizing of this article.
RELATED ARTICLE: Selecting the Right Speakers: Five Steps
1. Consider the application environment and determine which
features are needed. For example: Is this a presentation environment
where it will be necessary to mix a microphone
input wiht the multimedia sound?
2. Determine an upper limitt for your budget and identify thosee
systems that are under your budget limit.
3. From the results of Step 2, determine which systems can
meet the requirements established in Step 1. If no system
meets your constraints, you may have to revise your requirements
from both Steps 1 and 2.
4. Listen to the systems that were identified in Step 3. It is
best to do this in a situation where you can do an A/B comparison--where
two (or more) speaker systems are connected
through a switch to a common sound source, allowing
instant switching from one to another to compare audio quality.
Also, listen at the volume level desired in your application
to insure that distortion is minimal.
5. Finally, factor price into the decision, along with your judgment
from Step 4. Then choose the systems that is "optimal"
for your situation and finances.
RELATED ARTICLES: Multimedia Speaker Update
Dr. McKell's feature offers insight as to the features and functionality that educators should look for when considering multimedia speakers for use in instructional settings. And it compares systems that were available in late 1993 and nearly 1994. However, new offerings have since debuted. A brief rundown of those systems is provided here.
Distinguished by its "clam shell" style, the top-end ACS 300 systems as been updated to 300.1. The separate subwoofer unit has been redesigned, while the main speakers boast a new wiring system, a separate on/off switch and a jack for headphones. Meanwhile, the retail price has been lowered on it as well as on a similarly upgraded new ACS 100.1 model.
Altec's newest computer speaker system is the ACS3; it includes powered and shielded satellite speakers and a separate subwoofer. As a mid-range product, it's suggested list is $200.
KOSS offers a subwoofer specially designed to integrate into a multimedia a environment. The SW/1 Subwoofer has two four-inch speakers emphasizing the frequency range between 40 and 120 Hz to maximize deep bass performance. A single volume control is located on the front of the unit, as is an on/off button. Like other subwoofers in a three-piece system, it may bee placed anywhere; its dimensions are 5" x 10" x 12". The suggested retail is $129.
Offering a total of nine computer speaker systems, Labtec has high-, mind- and entry-level products. Their top model is the CS-1400 (sugg. list $149), an integrated, two-speaker system. Delivering 15 watts, each speaker boasts a unique two-way design with a 3" rolled-edge woofer and 2" alnico tweeters. All controls--volume, treble/bass, balance--are located on the front of one speaker. A headphone jack is included.
The CS-900 is two-way 7 watt system with a 4" rolled-edge woofer and dynamic high-frequency tweeters, plus separated slide controls for volume and bass are located on the front of one speaker, as is a headphone jack.
New multimedia speakers form Panasonic include a book-sized model, the EAB 710P, and the monitor-mountable EAB 401P. Both feature the Super Bass Exciter, which offers a lower floor of bass reproduction plus a wider bandwidth of bass sound. Both also use a proprietary Discrete Edge Speaker, in which the edge of the speaker hangs in mid air. This generates more crisp and clear mid-range sound and reduces distortion. Low magnetic leakage circuits help protect PC hardware and disks of data from accidental erasure.
The EAB 710P offers "3D sound in a 2-speaker system," according to the firm, because of its integrated sub-woofer. Separate amplifiers are provided for the woofer (10 watts x 1) and tweeter (5 watts x 2) units. Controls for volume, balance and bass are on the front of one speaker, as is a headphone jack and a jack for microphones. Suggested retail is $249.
The EAB 401P, at 12.7 oz. per speaker, comes with Velcro tape for mounting speakers on the side of a monitor; they can also stand separately. Its full-range speakers (150 Hz - 15 KHz) utilize a proprietary "twin loaded horn" system coupled with specially tuned acoustic tubes to reduce peaks and valleys in thee frequency reponse and expand reproductive range. Individual volume controls are on each speaker. Suggested retail is $145.
Sony Electronics, Inc.
Also offering a full line of speakers for computers, Sony's newest is the CSS-B100. Featuring an elegant design, the unit fits neatly beneath a computer monitor (15" to 17"). Its separate platform is designed to minimize the effects of sound vibration on a monitor screen, support the monitor's weight and provide magnetic shielding.
Two speakers are integrated into the CSS-B100; a large sound cavity and two-way bass reflex design deliver rich audio without a separate subwoofer. Frequency range is 70 Hz - 25 KHs; a 7 watt amplifier is built in. Front panel volume and bass controls, plus headphone, microphone and RCA jacks are included. Front and back panel input and output connectors offer extra flexibility. Suggested retail is $130.
RELATED ARTICLES: List of vendors
Acoustic Research 30 Turnpike ST. Canton, MA 02021
Altec Lansing P.O. Box 277 Milford, PA 18337 (800) 258-3288
Apple Computer Corp. 20525 Mariani Ave. Cupertino, CA 95014 (408) 996-1010
Bose Corp. The Mountain Framingham, MA 01701 (800) 444-2673
Creative Labs, Inc. 1901 McCarthy Blvd. Milpitas, CA 95035 (800) 998-1000
KOSS Corp. 4129 North Port Washington Ave. Milwaukee, WI 53212 (414) 964-5000
Labtec Enterprises 11010 NE 37th Circle, Unit 110 Vancouver, WA 98628 (206) 896-2000
Panasonic Communications & Systems Co. Two Panasonic Way Secaucus, NJ 07094 (800) 742-8088
Roland Corp. US 7200 Dominion Circle Los Angeles, CA 90040 (213) 685-5141
Sony Electronic, Inc. Computer Peripheral Products Co. 3300 Zanker Rd. San Jose, CA 95134 (800) 352-7669
Yamaha Corp. of America P.O. Box 6600 Buena Park, CA 90622 (714) 522-9011
Kenneth McKell is a student at Brigham Young majoring in computer science and a consultant with Sycon, Inc. His experience includes evaluating multimedia software and working with computer-midi interfacing and keyboard instrumentation. For many years he has also been involved in various musical performance groups. This combined background in music, computers, MIDI and multimedia provides significant expertise for assisting with this article.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||includes related articles on selecting speakers for multimedia sound|
|Author:||McKell, Lynn J.; McKell, Kenneth B.|
|Publication:||T H E Journal (Technological Horizons In Education)|
|Article Type:||Buyers Guide|
|Date:||Sep 1, 1994|
|Previous Article:||School as waystation on the information highway.|
|Next Article:||Developing a university's construction technology & mgt's computer learning center.|