Specifications

It is vitally important that all hardware used to suspend the APL-10, -12, or

-SB 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 mean

Grade 7, six marks mean 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 up, before any external load is

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

as when rigging plates are attached to the side of a speaker. In sheer, the fric-

tion provided by tightening and preloading the bolt actually increases the

strength of the joint and decreases cyclic failure of the fastener.

Consult an experienced rigger or engineer when it comes to rig-

ging practices, methods, required materials, or other details. The

kinetic energy from a 214 lb. object falling 40 feet onto a solid surface is truly

astounding. Injury or loss of life could occur, even to those who are not in

close proximity, let alone the injuries or deaths that may result from a pan-

icked crowd. Safety is the most important part of the job! Take the extra time

to obtain the proper rigging materials and components, or keep the system on

the ground! All rigging fittings, slings, Spansets™, shackles, bolts, and other

equipment should be inspected carefully before each use. Questionable com-

ponents or materials should immediately be discarded where they won’t be

found and re-used by someone else. In particular, forged eyebolts, shackles,

pins, and other high-carbon steel components are susceptible to fracture, if

they fall even a few feet onto a hard surface like a concrete floor. Play it safe

and do not use any questionable components or materials!

The optional Aeroquip

™ fittings provide a convenient way to suspend the

APL-10, -12, or -SB .They are available with hanging rings, studs that accept

a ‘jaw’ style attachment, and a combination of both ring and stud.

An Aeroquip fitting can sustain a straight-line-of-force load of 5000 lbs.

before failure.This means that if suspended from only two Aeroquip fittings,

the APL-10, -12, or -SB will exhibit at least a 46:1 safety factor. However, like

the nutplate,Aeroquip fittings de-rate rapidly as the load angle changes from

straight to oblique. It's vitally important to be absolutely sure that any and all

methods of suspending the loudspeaker do not result in the application of any sig-

nificant stress to either the nutplate fittings or the Aeroquip fittings in an oblique

line-of-force. Lives are at stake, possibly your own!