This month we look at large-format line arrays, which we define as those with 12-inch and larger woofers.
These “big guns” kicked off the modern line array revolution that has since seen the development of scores of models from professional audio loudspeaker manufacturers around the globe.
While the majority of line arrays models introduced of late have tended toward the smaller and lighter, there’s still exciting developments in the larger spectrum, as evidenced by the Martin Audio MLA (Multi-cellular Line Array) just unveiled at InfoComm 2010.
It’s still surprising to some in our industry that line arrays have been around for more that half of a century as column loudspeakers, and most of them in earlier days were voice-range only.
Their application was generally for highly reverberant spaces, where a narrow vertical dispersion avoided exciting the reverberant field, provided a higher Q (narrower dispersion pattern) and, as a result, improved intelligibility of the spoken word.
L-Acoustics V-DOSC line arrays were the first (in the mid-1990s) to show the concert sound world that more level and smoother frequency response can come from fewer drivers in a line array.
After everyone realized that for a given listening area, the drivers have no destructive interference in the horizontal plane and combine mostly in phase in the vertical plane, the race was on.
There are several possible enclosure designs. Some employ dual woofers with a center high-frequency section to provide horizontal symmetry.
The simplest 2-way systems may just have a single cone and high-frequency driver. Quasi 3-way solutions use dual woofers, but low-pass one woofer at a lower frequency than the other, eliminating cancellations at higher frequencies where their acoustic centers are farther apart than the wavelengths being reproduced.
True 3-way designs operate separate low-, mid- and high-frequency drivers, each in their own band. There are several approaches to horn-loading, which can provide higher sensitivity for additional power.
Most systems have companion subwoofers to provide improved low frequency coverage, pattern control and extension and for musical applications.
Some manufacturers also have complementary array elements with larger angles of coverage that perform better as the lowest near-throw enclosure in a vertical array.
Enjoy this look at numerous offerings in the category of large-format line arrays.