Thursday, 8 August 2013

Speaking of Speakers Part 3

There are many different types of speaker cabinet designs.

Line Arrays

Line Arrays have enjoyed a recent resurgence as the modern 'must have' speaker system. However their roots go back to the days when Town Halls all around the world had old style column speakers hanging in the corners. There is a saying in the sound industry that if you have to ask if you need a Line Array, you don't need a Line Array.

Line Arrays are particularly good at a narrow set of functions which limits their practical use to covering very long distances and covering wide areas. This makes them particularly useful for large outdoor concerts, but not brilliant in other scenarios. Line Arrays are relatively complex to setup and require a minimum of 4 to 6 individual cabinets joined together to work properly. They are also only practical when flown from the roof or a dedicated tower.

There has been a recent increase in small Line Arrays marketed at musicians and bands to take advantage of the buzz around the term. I don't recommended that you purchase a Line Array that you can buy in a music shop.

Passive Mid / High Speakers

These speakers are the most commonly used in the industry for small events.
They consist of one or two Mid Range speakers and a Horn speaker combined in a single speaker cabinet. They can produce almost the entire frequency range apart from the lowest sub bass frequencies. For extra bass they are stacked on top of additional Sub Woofers. There are two modes of operation, Bi-Amp and Passive Crossover.
In Bi-Amp mode, a separate amplifier drives the Horn Speaker from the amplifier that drives the Mid Range speakers. In Passive Crossover mode, a special device allows the entire cabinet to be powered by a single amplifier by splitting the frequencies and directing them to the right speaker.

Passive Crossovers are less than ideal but are low cost. Bi-Amping a speaker ensures that if a large amount of power is required for a split second to drive the Mid Range speakers, that it does not affect the power going to the Horn Speakers. This generally means Bi-Amped speakers are louder and clearer.