Larry Mundy is a "weekend musician" and has been building speaker cabinets to support that annoying habit for many years, as well as writing short on-line articles for fellow musicians and DJ's. His knowledge of pro audio speakers and his experiences (both good and not-so-good) are digested here to help the budget-minded performer achieve good sound, even in a first time project.
Table of Contents or Excerpts
Chapter 1: Some Basic Principles
Frequency response, Efficiency, Impedance, Directionality, Phase, Power Handling, Proximity Effects
Chapter 2: Selecting Low-Frequency Drivers
Type, Size, Efficiency, Voice Coils, Magnets, Frequency Range, Xmax, Thiele-Small Parameters, Frames, Surrounds, Cone Materials, Dust Caps
Chapter 3: Selecting High-Frequency Drivers
Frequency Overlap, Compression Drivers, Piezoelectric Drivers, Midrange Drivers, Horns and Horn Lenses, Power Ratings
Chapter 4: Enclosure Design
Driver Parameters, Computer Modeling Chapter 5: Crossovers, Efficiency Matching and Piezos
Capacitors, Chokes, Voltage Ratings, Passive Crossover Circuits, Driver Attenuation, Piezoelectric Tweete
Chapter 6: Multiple Drivers: Wiring and Impedance
Parallel and Series Wiring, Impedance Mismatches
Chapter 7: Parts and Pieces
Types of Coverings, Grilles, Corners, Handles, Top Hats, Jackplates, Casters, Checklist
Chapter 8: Enclosure Dimensions and Shapes
Rectangles, Trapezoids, Wedges, Line Arrays, Cabinet Dimensions, Driver Arrangement
Chapter 9: Construction: Woodworking 101
Tools, Materials, Measurements, Assembly Techniques, Bolts and Fasteners, Balancing
Chapter 10: Covering and Assembling the Cabinet
Adhesives, Dampening Material, Wiring, Preventive Maintenance
Chapter 11: Some Sample Projects
Two-way 12" PA Speakers
- Two-way PA Speakers with Multiple Bass Drivers
- Three-Way PA/Instrument Speaker
- A Stereo Guitar Cabinet
- Amplified Cabinet with Nearfield Monitors
Chapter 12: Subwoofers and Bi-Amping
Electronic Crossovers, Multiple Amplification, Subwoofers Ð Horns, Bandpass and Bass-Reflex
Chapter 13: Wiring and Connectors for Stage Cabinets
Phone Plugs, Instrument and Speaker Cables, Banana and Speakon Connectors, Internal Cabinet Wiring
Chapter 14: Reconing a Driver
When to Recone, When to Replace, Finding a Reconing Service
Chapter 15: Homemade Rack Cases
Rackmounting, Rack Case Construction
Chapter 16: Sources: Programs and Parts
Computer-Modeling Programs, Drivers and Accessories
Since I started building speakers for live-sound use in the 1970's, there have been a number of advances in loudspeakers, computer modeling and our understanding of how live sound works. All these allow the working musician or DJ to select or build speaker cabinets that vastly outperform the designs of the past. But there is very little in the way of published how-to information to get you started doing this.
This book is written primarily for musicians on a budget, who want to perform live in front of audiences large enough that their music requires electronic amplification. Since performing music is only lucrative for a very few performers, I figure most musicians are 'on a budget,' if not actually flat broke. We perform gig after gig, hoping that our equipment can stand the strain of just a little more volume, or one more trip in and out of the van, wincing at the high prices of the latest equipment in the local music store.
For most of us, being a gigging musician or DJ also means being a part-time electrician, mechanic, carpenter, acoustic engineer and heavy-equipment mover. If you are not rich and/or famous enough to have someone else haul, set up and repair your equipment, you learn many of these skills whether you want to or not. While this book is primarily about designing and building your own liveperformance speakers, I hope it will make you a more careful consumer of factory-built speakers as well.
Some of my advice might not be considered technically complete by a professional acoustical or electrical engineer. While IÍm impressed at the depth of technical analysis possible for apparently simple principles of physics, a more detailed and technical approach might be hopelessly confusing, or simply irrelevant, to someone who simply wants to get started building a speaker. Likewise, the machinery and construction techniques of big manufacturers are geared to fast production, sales volume and minimum component cost. I can tell you from experience, you can build excellent livesound speakers without any exotic tools or an engineering background. I hope I am able to translate some fairly complex concepts into language understandable by the average person interested in building a speaker system in the garage.
I will discuss a number of live-sound concepts and speaker-building techniques in the following pages. Then I will demonstrate a few real-world projects I've built, noting the challenges that popped up along the way. These are, as they say, 'for illustration only.' I don't represent that they are the best designs; they were built for my personal use and I would not be at all disappointed if none of the readers of this book built copies of any of them. One of the joys of building your own speakers is the ability to tailor what you build to your unique wants and needs.
Q: Can I really do this myself?
A: Yes. You can, if you're willing to spend a little time and effort. Building your own speakers requires planning and getting dirty. Most people have automobiles, but they don't build them from parts and probably have no idea what a power-steering pump does; they just know they fill the tank and turn the key and their car takes them somewhere. If it breaks, they have it towed to a repair shop, and if it's too small or big or slow they trade it for another one. If you have never opened the hood of your car, never tried to fix a broken kitchen appliance, donÍt own a single power tool and beg to have a ñtechnicalî friend come hook up your home stereo, this book is probably not for you.
But I've met very few gigging musicians or DJ's who don't have a fairly good idea of at least some technical concepts about live-sound reproduction. They've had to learn because they set up their own equipment. Or they've experienced embarrassing equipment failures. Or they've spent lots of hard-earned money on pro-audio equipment that looks very impressive but doesn't sound nearly as good as someone else's smaller, cheaper setup. This book will 'look under the hood' of live-sound speakers and describe, in something approaching layman's terms, why they look and work and sound the way they do. And if you have a few power tools and have nailed together a birdhouse in the distant past, you can build stage speakers you can be proud of
If you are a novice at all this, you may learn something useful from an evening's reading even if you never build anything. There is a lot of existing equipment out there that could benefit from upgraded drivers, or even a slight change in internal wiring. But there is no better way to understand live-sound speakers than to build one. It's not difficult, but if you want to end up with a speaker that's as good as (or better than) its store-bought equivalent, you'll need to do a little research and planning, and avoid some common mistakes that happen when you just nail up a box and stick a speaker in it.