Specifications

(6) Flying the APL-220, -500, and -800

For many applications, the APL-220, -500, or -800 may need to be flown.This

requirement commonly occurs in television work, political conventions, the-

atrical productions, rock concerts, permanent installations, and numerous

other applications. Flying an APL-220, -500, or -800 or an array of them offers

many advantages – the downward angle can easily be adjusted, the horizon-

tal rotation may be easily adjustable (depending on the hanging method), and

the height can usually be optimized for best coverage with minimal bleed

onto the stage.

APL-220, -500,and -800s perform perfectly well when flown;in fact, they have

been factory optimized for a free field environment and often sound better

when in the air as opposed to on the ground. Some loss of bass response will

occur, however, when any speaker is suspended in space as opposed to being

located near a wall, floor, ceiling, or other boundary surface(s).

The APL-220, -500, and -800 are equipped with four rigging points – two on

the top and two on the bottom.These points are supplied with either Apogee

nutplates or Aeroquip pan-fittings, as specified at purchase (types of fittings

can be changed easily in the field to accommodate varying requirements).

If the rigging fittings are to be changed, always use the screws that are sup-

plied from the factory – never use generic screws purchased at a hardware

store, they are unsafe for this application!

Nutplates are circular steel plates with a welded 3/8-16 threaded fastener in

the center, designed to accept 3/8-16 threaded bolts (also available in Metric

M-10 version). Each nutplate can sustain a straight-line-of-force load of 2500

lbs. before failure. An APL-500 weighs 80 lbs., so if only two nutplates are

used to suspend the speaker, the safety factor will be 62:1 (NOTE: OSHA

requires a 5:1 safety factor, whereas most theatrical rigging shops have vol-

untarily adopted a 7:1 safety factor).

It is vitally important that all hardware used to suspend the APL-220, -500, or

-800 be of the highest grade materials and construction. All bolts must be

SAE Grade 7 or better. The American bolt-grade rating system is often

depicted by a number of linear hash marks on the head of the bolt – five

marks means Grade 7, six marks means Grade 8.

If eyebolts are used, they must be forged and of the shoulder-type. Eyebolts

are designed for a straight-line-of-force. They de-rate rapidly and become

unsafe as the load angle deviates from the 0 degree axis (in line with the

length of the threaded bolt).

All bolts must be tightened securely, but not over-tightened (5-7 ft. lbs. of

torque is generally sufficient for 3/8" bolts). Over-tightening can cause much

of the tensile strength of the bolt to be used before any external load is

placed on it. An exception to this rule is when the bolt is used in sheer, such