Operating instructions

CHAPTER 2

NOTE: Although the LD-3 offers a large gain

range (-6 to +6 dB) for each output, gain

tapering is not recommended for arrays. Adjusting

zones with an overall amplitude control for each

zone results in the following:

1. Directionality decreases.

2. Low-frequency headroom decreases.

3. The length of the line or curvilinear array

column is effectively shortened.

Distance Control

The green Distance control allows you dial-in the throw from

the array on each output channel, from 0 to 150 meters.

NOTE: Setting distance to 0 meters bypasses

the atmospheric correction functions.

A convenient feet (ft) to meters (m) conversion table is

located to the bottom left of the Atmospheric Correction

section (Figure 2.8).

Figure 2.8. The LD-3 includes an easy distance conversion reference

table stenciled on its front panel.

Setting the Distance enables the LD-3 to adjust the

correction curve according to the throw of the loudspeakers

on each channel. This setting corresponds to coefcients

(in increments from 2 to 10, increasing as distance

increases) which provide just the right amount and shape

of correction as a function of the other atmospheric

variables (Temperature, Altitude, and Relative Humidity). As

suggested by Figure 2.9, there are a multitude of correction

scenarios for even a handful of distances.

NOTE: After dialing in a new distance for any

channel, press the Enter button.

Figure 2.9. Sample atmospheric correction curves for the attenuation of sound in air at 10, 20, 40 and 80 meters.