Powered (Active) vs. Unpowered (Passive)
If you’re not familiar with active PA speakers, the important thing to know is that the power amplifier and crossover are built into the same cabinet as the speakers. The benefit of this is that all you will need are the speaker and a sound source, whether it be a mixer, music player, or even your instrument in certain circumstances. Powered speakers simplify your PA system and are faster and easier to set up, but they aren’t always the best option for designing complex systems for permanent installation in large auditoriums and halls.
Passive PA speakers require separate power amplifiers and sometimes crossovers, too. For most gigging bands or small- to medium-sized venues, passive speaker systems may not be the simplest option for a sound system. But for larger, more complex systems, it can be a huge benefit to have your system components separated. Because of the extreme amount of power required for large systems, keeping the amplifiers separate prevents your speakers from being overheated by the amps, and system maintenance in the long term is much easier when you don’t have to climb to the rafters to adjust your amplifier settings.
As you can see, choosing between active and passive PA speakers has more to do with how you’re using the system, than whether one type is superior to the other. Gigging bands and small venue owners may prefer the simplicity and reliable sound quality of active systems, while touring professionals and large installations may prefer the versatility and modular nature of a passive system.
Bi-amplification is the process of dividing an audio signal into two frequency ranges, which are then sent to two separate amplifiers that, in turn, drive separate loudspeakers. An active crossover network sends low frequencies to the larger driver and high frequencies to the smaller driver. Bi-amping also allows the amplifier(s) to be chosen or designed specifically to match your speakers and enclosures. Bi-amping, tri-amping, and beyond have been used in sound reinforcement systems for years and have become quite common in active studio monitors as well.
A crossover is a device that divides an audio signal into separate frequency ranges, ultimately routed to different drivers (speakers, tweeters, horns, etc.) in an audio system. For example, a 2-way crossover may comprise of a lowpass filter that passes a signal with low frequencies to a woofer and a highpass filter to send frequencies appropriate for the tweeter. Crossovers can have passive or active designs. You don’t need to know everything about crossovers to set up a decent system, but knowing where the crossover points lie in the sonic spectrum can help you set up a better mix.
An All-in-one PA Solution
If you’re a solo performer, you’re probably researching PA speakers and equipment without much enthusiasm. You need to sound great whenever you perform and don’t want to invest more time, energy, and money into your system than you do into your music. There are all-in-one solutions for you that integrate active speakers, signal processing, and even effects into a simple, compact design. For singer/songwriter types, coffeehouse gigs, and small acoustic ensembles, these PA systems can save you money, time, and space.
Intelligent Speaker Systems
Hey, it’s the 21st century! There are now speaker systems that can automatically recognize what you’re plugging into them and will optimize their sound accordingly. Some can recognize whether you’ve arranged them vertically on speaker stands or horizontally on the stage as floor monitors and will automatically optimize their sound for that orientation. Other built-in intelligent features can include automatic feedback suppression, networking capability, and remote control. How you plan on using your system on a regular basis determines which of these advanced features, if any, will ultimately benefit you.
Do I Need a Subwoofer?
You’re probably aware that subwoofers are just speakers optimized for reproducing the lowest bass frequencies. What isn’t as commonly recognized is that adding subwoofers doesn’t necessarily make your system louder: they can actually allow you to run your system at a lower overall volume while still maintaining full-range punch and impact.
Subs usually focus on the 20Hz to 100Hz spectrum, which is difficult to reproduce accurately with standard PA speakers. If a subwoofer was incorporated into a full-range speaker, the performance of the mid- and high-frequency drivers would be compromised due to the intense vibrations of the powerful bass frequencies. Said another way, larger PA speakers can respectably reproduce low frequencies, but for true full-range sound, you need a dedicated subwoofer.
Subwoofers aren’t just for dance music and bass-heavy material. They can also play an important role in filling out the sonic spectrum for any performance. Subs also allow your main speakers to sound better, giving them valuable headroom to better reproduce the dynamics of your performance. As with full-range speakers, subwoofers can either be active or passive.