A live music system usually isn’t complete without subwoofers. Whether horn loaded, cardioid, bass reflex, infinite baffle, or band pass, they are a bedrock of pop and rock music, as implicit as the kick drum mic in channel one.
Though initially developed to extend LF response in the 1960s and to enhance supplemental effects for 1970s disaster movies, subwoofers – dedicated band-limited cone loudspeakers for frequencies generally below 100 Hz – have grown to become the most ubiquitous specialty enclosure.
For years, dedicated subwoofers accompanied modular full-range enclosures with predictable tops-to-subs deployment ratios, depending on the type or style of music. Two-to-one for pop music, one-to-one for rock and one-to-two for reggae and rap. This was as complicated as subwoofer math initially got.
Over time, greater understanding of low-frequency physics has resulted in refinement of the general approach to subwoofers, starting with driving them from an auxiliary send, sending only specific inputs, such as bass and kick. A bit later, mains were delayed to compensate for LF propagation delay.
The advent of line arrays, with their increased effectiveness and ability to throw mids and highs great distances with superior pattern control, outpaced the capability of many older subwoofer designs. The need to throw bass further and more efficiently led to subs that are flyable, cardioid by construction or array design, horn-loaded for efficiency and with higher power transducers.
There are plenty of subwoofer applications outside of larger main systems. In-ear monitors create a demand for on-stage supplemental subs for drummers. Corporate and distributed portable applications benefit from pole cups for elevating small 2-way systems.
A great way for a system to have more impact –- in an arena, club, church, corporate event and even karaoke – is to beef up its ability to move more air. Enjoy this Real World Gear Gallery Tour of recent subwoofers.