Specifications

Obviously, the phase integrity of the entire signal processing chain must be

maintained for this to occur. Is absolute phase audible? Should you be con-

cerned? Yes, it is audible and although subtle, it makes a big enough difference

to warrant taking the time needed to insure that the signal chain is phase-

positive throughout.You’ll hear an improvement in sonic impact, especially in

the lower frequencies.We recommend that absolute phase be kept positive

in all low-frequency devices whenever possible.This can be checked with a

small handheld style phase response test unit, available from numerous man-

ufacturers.Although it’s simple and easy to use the Phase Reverse Switch on

the subwoofer to determine its best phase relationship to the full-range

speaker system it is being used with; if the best position turns out to be

reversed, we recommend that you instead reverse the full-range system(s)

with phase reversal adapters, so that the subwoofer(s) can remain in a posi-

tive absolute phase state.

(6) Flying the APL-10, -12, and -SB

For many applications, the APL-10, -12, or -SB subwoofer may need to be

flown.This commonly occurs with television award shows, political conven-

tions, and other events where the audience is located too close to the stage

to allow the subwoofers to be placed in the typical side or front-of-stage

position. APL-10, -12, and -SBs perform perfectly well when flown; in fact, the

sound quality is often perceived as being superior when the speakers are in

the air as opposed to on the ground. This is usually because they integrate

better with the flown full-range speakers when they are in close proximity to

them, although it can also be because of the acoustical characteristics of a

given room, or a combination of both. However, be aware that the same num-

ber of units that performed satisfactorily on the ground or in a corner will

have to be doubled or tripled to achieve the same power output level when

they are flown.

The APL-10 and -12 are equipped with four rigging points – two on the top

and bottom of the APL-10 – and two on either side for the APL-12. The APL-

SB is equipped with two rigging points – one on either side.These points are

supplied with either Apogee nutplates or Aeroquip pan-fittings, as specified at

purchase (fitting types can be changed easily in the field to accommodate

changing requirements). If the rigging fittings are to be changed, always use the

screws that are supplied from the factory – never use generic screws purchased

at a hardware store because 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. (1136 kg) before failure. An APL-12 weighs 214 lbs. (97 kg), so if only two

nutplates are used to suspend the speaker, the safety factor is 23:1 (NOTE:

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

voluntarily adopted a 7:1 safety factor.).