The device commonly referred to as a “speaker” is more correctly referred to as a loudspeaker system. It is comprised of some transducers, a crossover network, an enclosure, and a few additional parts.
Loudspeaker system designers must be familiar with the complicated interactions of the components that form the system.
An assemblage of good parts does not guarantee a good system. (Note: For the remainder of this article I will refer to a loudspeaker system as simply a “loudspeaker.”)
If I had to pick one word to describe the loudspeaker design process it would be compromise. Every facet of a loudspeaker’s performance and ultimate cost is a result of trade-offs.
This is why it is very difficult to compare loudspeakers from different manufacturers. One may appear to be better by focusing on a single specification (such as its power rating), yet it may be inferior as a system when the performance of the whole is considered.
Let’s look at the parts that make up a loudspeaker in order to get a better understanding of why some are more expensive than others.
The Lowdown on Transducers
The heart of a loudspeaker is its transducers. These are the devices that actually convert electrical energy into acoustical energy. Most sound reinforcement transducers are pistons.
Today’s designs have changed little in operating principle from those produced by research done early in the last century. Technological advancements have produced better materials, lighter weight, and lower cost, but loudspeakers still basically produce sound by vibrating the air molecules around them through movement.
No single transducer can reproduce full-range sound at the levels required for auditorium use. For this reason most loudspeakers are two-way or three-way designs, with dedicated transducers for the low-frequency (LF), mid-frequency (MF), and/or high-frequency (HF) parts of the spectrum.
Three-way designs have more transducers, so they typically cost more than two-way designs.
All-Important Frame Design Components
One factor that makes a big difference in the price of low-frequency transducers is the frame design. Stamped frame loudspeakers are lower cost due to their ease of fabrication and lower raw material cost. Cast frame loudspeakers have less of a tendency to flex as the cone moves in and out.
They also tend to have higher mass and weight than stamped-frame models, as well as higher cost. Since transducers waste much of the applied electrical power, performance improvements can be realized by improving heat dissipation.
The cone material must compromise mass, strength, and cost. While some esoteric materials have been developed for loudspeaker cones, paper remains the most common material because it represents a good compromise between the required attributes. LF transducers range in cost from tens of dollars to hundreds of dollars.