Loudspeakers in the Field

From across a dark stage, most loudspeakers are the same black trapezoid. The differences that matter — powered or passive, wedge or front-of-house, top or sub — are readable in seconds once you know where to look, and reading them wrong is how a monitor ends up pointed at an audience and an amplifier ends up driving a box it was never matched to.

The loudspeakers lesson covers the physics: what each enclosure type trades away, why high frequencies need a horn, what a crossover costs. This chapter is the identification and handling half — telling the boxes apart, connecting them without damage, and putting them where they can actually do their jobs.

Reading the Box

• Powered (active) speakers — an amplifier and crossover built in. Identification is instant: a mains inlet (usually powerCON or IEC) next to an XLR input, and usually a small control panel with level and DSP presets. They take a line-level signal, never an amplifier's output — feeding one from a power amp is a destroyed input stage.
• Passive speakers — just drivers and a crossover in a box. speakON or (on older gear) jack connectors, no mains inlet, no controls. They need an external amplifier, and the pairing is a real decision: the power lesson explains why the box's impedance and the amp's rating have to be read together.
• Full-range tops — a woofer and a horn in one cabinet, covering everything a small show needs except the bottom octave. The pole socket in the base marks a box that expects to live at head height.
• Subwoofers — one big driver, no horn, often no visible driver at all behind the grille. Many have a crossover or "through" output that feeds the tops only what the sub isn't handling — the standard sub-and-top package puts the pole in the sub's top plate.
• Stage monitors (wedges) — the angled cabinet built to lie on its bevel and fire up at a performer. The angle is the identification and the function; a wedge stood upright facing the room is a bad main, and a main lying on its side is a worse wedge. The monitors lesson covers what goes through them.
• Line arrays and column PAs — multiple small drivers in a vertical stack, hung in curved arrays in big rooms or sold as slim "column on a sub" systems for small ones. The vertical stacking is the point: it controls how the sound spreads floor-to-ceiling, which flat rooms full of people care about.

Connecting Without Damage

The signal-family rules from the connectors chapter of this manual do most of the protective work: line level on XLR into powered boxes, amplifier power on speakON into passive ones, and never an adapter bridging those worlds. What is left is order and level. Powered speakers come on last and go off first, so the thumps of everything upstream powering up never reach the drivers at full amplification. Start with the box's input level at its marked nominal (usually the detent), not full — a powered speaker at maximum input sensitivity turns the desk's gentle mistakes into loud ones, and the gain-staging lesson's whole argument applies from desk to driver.

DSP presets on powered boxes are worth taking seriously, because they re-voice the box for its actual job: a "monitor" preset typically trims the low end that a floor position would otherwise inflate, a "with sub" preset high-passes the top so it stops wasting excursion on bass the sub is already producing. They are not tone flavours; they are configuration. Set them deliberately and check them at load-in, because the last band's settings are still in there.

Placement, in Brief

Placement is covered properly in the rooms lesson and the outdoor lesson; the field summary is short. Get horns to head height or above — pole-mount or fly, don't floor-stack tops. Keep mains in front of the microphones, which is most of the feedback battle won before it starts, as the feedback lesson explains. Put subs on the floor (the floor helps them), and know that a sub against a wall or in a corner gets louder and lumpier at once — sometimes useful, never neutral. And aim boxes at people, not at glass, plaster or each other: every surface a PA hits before the audience is a second, later copy of the show.

Weather is a placement issue too. Most portable boxes are rain-resistant at best; a powered speaker is mains electronics in a cabinet, and an outdoor stage without cover for it is a cancellation waiting on a forecast.

Moving and Not Breaking Them

Loudspeakers die in transit more than in use. Modern lightweight cabinets still carry drivers whose magnets dislike drops; grilles bend into cones; connector panels are the least protected face. Handles exist where the maker balanced the box — use them, lift with legs for anything over about 20 kilograms, and make sub-stacks somebody's explicit two-person job. On stands, the rules from the stage-hardware chapter of this manual apply verbatim: legs fully spread, mast no higher than needed, and outdoors a stand is not deployed until it is weighted.

The failure mode worth understanding is the quiet one: drivers are more often killed by a clipping amplifier than by a big clean signal, because clipping pours sustained energy into the tweeter — the power lesson explains the mechanism. So the "protect the PA" instinct of turning the amp down and the desk up is exactly backwards; keep headroom upstream, and let the biggest number in the chain be the amplifier's rating, not its input.

What to Check Before the Next Load-In

• Mains inlet means powered, speakON means passive — establish which before anything is connected, every time.
• Line level into powered boxes, amp power into passive ones — no adapter makes the other combination safe.
• Powered speakers on last, off first, input at nominal — the thump you never hear is the driver you keep.
• Check the DSP preset, don't inherit it — the box remembers its last gig, not yours.
• Horns at head height, mains ahead of the mics, subs on the floor — three placements that solve most rooms.
• Wedges lie on their bevel and point at performers — anything else is a differently-shaped mistake.
• Fear the clipping amp more than the loud one — sustained clip kills tweeters that clean peaks never touch.