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	WPI Technical Theatre Handbook: Speakers
	Speakers The final element in a sound system is the loudspeaker. The purpose of the speaker is to convert an electrical representation of sound into mechanical vibrations. Many different types of speakers exist, making choosing the right one for the job a difficult task. Making the right choice involves balancing several factors including size, sound quality, efficiency and power handling. A typical speaker is made up of several components. One or more drivers are mounted in a cabinet, generally made out of wood or plastic. There are many kinds of drivers, each suited to reproducing a particular range of sound. Bass drivers (often called woofers) reproduce low sounds. Midrange drivers reproduce the sound in the middle of the audible frequency spectrum. High-frequency drivers (usually called tweeters) reproduce the top end of the audible frequency spectrum. Some speakers contain two or three drivers that can respond over much of the audible frequency spectrum. These speakers are often called full-range speakers. Other designs exist in which indivual cabinets house drivers, but the whole speaker is not capable of reproducing the entire audible frequency range. For example, it is common to find two-cabinet speaker setups. One cabinet houses a tweeter and a mid-range driver, while a second cabinet houses a woofer. Figure 6.9: A 3-way full-range speaker, manufactured by JBL. Speakers can range in size from a boxes a few inches a side to boxes and other shapes several feet per side. Generally cabinets that handle bass are larger than those that handle mid-range or high frequencies. High-powered mid-range and high drivers can be built into fairly small packages separate from bass units. Units such as this are becoming common in consumer audio, and have some application to theatre audio. These so-called subwoofer/satellite systems are ideal in some cases because they allow the relatively large bass cabinets to be hidden, as bass frequencies tend to be non-directional. The remaining satellite speakers are usually small enough to be mounted in convenient, inconspicuous locations. Schemes such as this are often preferred in theatre applications because having large unsightly speakers flanking a proscenium stage is typically not desirable. However, systems of this nature tend not to be able to produce incredible amounts of volume, and they often do not sound as good as other designs. Use of information in this document implies understanding and agreement with the copyright and terms of use. Specifically, no warranty is expressed or implied regarding the accuracy of the information contained within. YOU USE THIS INFORMATION AT YOUR OWN RISK. All trademarks are property of their respective owners. You must obtain permission from the author before using the contents of The Handbook for anything other than private use.	Table of Contents [Whole book in PDF 5.3MB] Contents Introduction Goals Sources Methods Conclusions Costumes Introduction Procurement Fabrics Color Patterns Fitting Rehearsal Clothing Design How to Begin Color Practicality Documents The Set Introduction Set Pieces Platforms Flats Stairs Rakes Other Structures Floor Coverings Construction Materials Tools Finishing Painting Types of Paint Mixing Paints Applying Paint Draperies Design How to Begin Documents Computer-Aided Design A Typical Set Construction at WPI Rigging Introduction Common Rigging Hardware Rope Wire Rope Thimbles, Wire Rope Clips, and Swages Shackles, Turnbuckles and Hooks Chain & Rapid Links Slings Fly Methods Non-Counterweighted Pulley Systems Counterweighted Fly Systems Lifts Chain Motors Flying Set Pieces Lighting Introduction Lighting Instruments Scoops Cyclorama Lights Parabolic Reflector Cans Fresnel Spotlights Ellipsoidal Reflector Spotlights Automated Instruments Color Color Theory Primary, Secondary and Complementary Colors of Light Light Mixing Practical Use of Color Glass, Gelatine and Plastics Dichroic Color Filters Patterns Dimmers Dimmer History Cables and Connectors Lighting Boards Control Design Washes Specials Cyclorama Lighting Color Lighting Angle Simulating Exteriors Lighting Design Paperwork Shop Order Instrument Plots Focus Sheets Computer-Aided Lighting Design A Typical Lighting Hang at WPI Audio Introduction Input Microphones Converting Sound to Electricity Directionality Analog Tape Digital Audio Tape (DAT) Compact Disc (CD) Mini-Disc (MD) Digital Samplers Computer Sound Cards Mixing Boards Signal Processing Equipment Equalizers Compressors and Limiters Noise Gates Effects Processors Output Power Amplifiers Speakers Crossovers Cabling and Connectors Line-Level Speaker-Level Automation Design Creating and Obtaining Effects Editing and Processing Effects Designing the Sound System The Input Section Signal Processing The Output Section A Typical Audio Setup at WPI Power Introduction Basic Theory Power Feeds Power Distribution Boxes Power Protection Important Considerations Special Effects Introduction Animated Costuming Smoke and Fog Pyrotechnics Acknowledgements References List of Figures Index About this document ...

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