Telex ISP-100 manual Three-way, Four-way, Low, Low-Mid, Mid, Mid-High and High Controls, Slope

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depending upon whether 12 dB/octave or 24 dB/octave filters are used, respectively.

The following sections will show this sum-to-allpass trait to hold true for the ISP-100 Linkwitz-Riley 3-way and 4-way crossover implementations.

Three-way

From Figure 8-6

Summed Response = LP1LP2 ± HP1LP2 ± θ1HP2

=(LP1 ± HP1)LP2 ± θ1HP2

=θ1LP2 ± θ 1HP2

=θ1(LP2 ± HP2)

=θ1θ2 Q.E.D.

There is an alternate configuration, not implemented in the ISP- 100, that also has this property:

Summed Response = LP1θ2 ± HP1LP2 ± HP1HP2

=LP1θ2 ± HP1(LP2 ± HP2)

=LP1θ2 ± HP1θ2

=(LP1 ± HP1)θ2

=θ1θ2 Q.E.D.

Four-way

From Figure 8-9

Summed Response = LP1LP2θ3 ± HP1LP2θ3 ± θ 1HP2LP3 ±θ1HP2HP3

=(LP1 ± HP1)LP2θ3 ± θ1HP2(LP3 ± HP3)

=θ1LP2θ 3 ± θ 1HP2θ3

=θ1(LP2 ± HP2)θ3

=θ1θ2θ3 Q.E.D.

Low, Low-Mid, Mid, Mid-High and High Controls

The Low, Low-Mid, Mid, Mid-Highand High buttons determine if that section of the crossover is bypassed. If the word Low, Low-Mid, Mid, Mid-High or High is displayed on the button, then that portion of the crossover is not bypassed. If the word Bypassed is displayed on the button’s face, then that portion of the crossover is bypassed. Clicking on the buttons will toggle their settings.

Link/Unlink Control

The Link/Unlink button determines if the settings in the crossover track their corresponding partners. A simple rule of thumb is that when the sections are linked, the component on the right will track its partner on the left. Clicking on the button(s) will toggle the settings.

Slope

To change settings, click on the arrow next to the number in the text box. A selection list will appear. The list may or may not be scrollable. To make a selection click on the desired entry.

Processing Components - Crossover