Designing a loudspeaker system is a lot easier today than it was in the past. It used to be that only a limited number of drivers were available, and there was a lot of trial and error involved in making the boxes. Now we’re blessed with two major improvements.
First, we have computers to help us, and programs like BassBox Pro and Hornresp make it easy to design and make changes to the design without ever having to cut a single piece of wood. Further, measurement software programs allow us to quickly verify that the finished cabinet has achieved the intended design goals.
The second improvement is that there are a wide variety of great performing transducers to choose from. In this month’s Real World Gear Photo Gallery Tour, we look at both woofers and compressions drivers. When choosing these devices for your loudspeaker project, be aware of a few parameters.
The power rating tells us many watts of power a transducer is designed to work with. However, it does not inform us as to how loud a device will go – this is job of the sensitivity specification, which states in decibels (dB) how loud a particular transducer will play given a particular input, usually referenced to 1 watt of input signal measured at 1 meter distance from the driver.
Simply put, the higher the number, the louder the output of the driver. A transducer with a lower wattage rating but a higher sensitivity rating can have a louder output than one with a higher wattage rating but lower sensitivity. The frequency response is the range that the unit is designed to reproduce, which is relatively self-explanatory. But, as you’ll see in the listings in our Photo Gallery Tour, these do vary between what appear to be similar devices.
For compression drivers, two additional things to look for are throat size and mounting configuration. Drivers normally fall into these throat-size groups: 1-, 1.4- (or 1.5-) and 2-inch. Generally speaking, the larger the throat, the larger the diaphragm and the lower in frequency range the driver can operate in.
Diaphragms can be made of many materials, with aluminum and titanium being the most popular. For mounting to a horn, compression drivers use a variety of bolt hole configurations, and smaller sized drivers can also be designed with threads to screw on to the horn so make sure your driver and horn use the same mounting system or hole pattern.
Enjoy this Real World Gear Photo Gallery Tour of a variety of recently developed cone and compression drivers.