Single 18 inch subwoofers are some of our most popular pro audio loudspeakers that we offer here at Direct Pro Audio. They offer the best balance of extreme output, while still retaining a decent ability to be transported without the need for a group of ten hungry roadies.
There are two basic types of single 18 inch subwoofers, those that have a built-in power amplifier, and those that require an external amplifier. Those with a power amp built-in we call self-powered, or active subwoofers. Those that need an external amplifier we refer to as passive subwoofers. No matter which type you select, leave room in your budget for an electronic crossover so that you can squeeze every drop of power and fidelity out of your pro audio sound system.
There are basically two different designs that dominate the pro audio subwoofer offerings today. The first is called a direct-radiator. In this type of subwoofer, the low frequency device (woofer) is mounted right up in front for all to see. A nice metal grill typically protects the woofer from damage. The benefit of a direct-radiator is that the sound you feed it, is what comes out of it. The drawback is that it is not capable of throwing the low frequency a great distance. A great example of this typ of subwoofer is the Mackie S518S.
The second design is called a horn loaded design. In this subwoofer, you typically don't see the woofer because it is mounted deep inside so that the sound goes through a tunnel or channel of sorts which allow the bass to be thrown a great distance. The drawback is that they lose some of the ability to accurately reproduce the tone that you feed it. An example of this type of subwoofer is the Peavey SP FHBX.
There are a few hybrids that combine the best of both direct radiator designs and horn loaded designs. The hands down favorite example in this category would be our pride and joy subwoofer, the Yorkville LS801P. It has great tone, and can throw the sound for a great distance, even outdoors. The LS801P and the model that came before it, the LS800P still grace our rental department after ten plus years.