Proel PC260 - Manual (Page 20)

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The UNIT parameter allows to set the delay unit in us (microsecond / 10 -6 s), ms
(millisecond / 10 -3 s), mm (millimeter / 10 -3 m), m (meter), inch and feet values .
To access the delay section, press the DELAY button and then the EDIT button
of the channel you want to edit . Push the DATA knob to select the parameter to
edit and rotate the knob to adjust it:
Note: The effect of air temperature is also automatically calculated for the total
delay time using the Temperature value entered in the Setup Menu .
IMPORTANT: Make sure that the Master A and B input channels delay is exactly the same when an output is routed from
the A+B sum. We recommend to link the inputs (ganging) to make sure that the same delay is applied to both inputs.
Failure to do that could cause unexpected results on each A+B sum output (internal comb filtering).
GEQ - graphic equalizer
In the GEQ section you can control the 28-bands 1/3 octave graphic equalizer of each
input channel . The GEQ is controlled using gain sliders, just like you would do in a normal
graphic EQ .
To access the first page of the graphic EQ section, press the GEQ button and then the EDIT button of
the input you want to edit . Push the DATA knob to select the parameter to edit (GAIN or FREQUENCY)
and rotate the knob to adjust it:
In the second page of the GEQ section there is a useful BYPASS function for comparing the sound with and without EQ . In addition,
it's possible to select the response TYPE of the equalizer, by changing the shape or “Q” of the single cells . The behaviour of each
type is shown below .
The “EZCurve” type is based on the Proel’s EZCurve analog Graphic Equalizer’s response . It has a “Q” that varies with cut/boost
applied - wider ‘Q’ at lower values of cut/boost - resulting in a smoother response when smaller amounts of EQ are added .
INFORMATION NOTE: Subwoofer delay time adjustment
PC260 processor allows the adjustment of the delay to allow the correct alignment of the system . The default setting gives the correct
temporal alignment for when the tops are set up directly above the subwoofers; in any other case, the delay should be adjusted to
correct the alignment . The delay to be added to the preset can be calculated quite simply . The above figure showsan example of this
alignment . The system is composed of a flown satellite and a subwoofer positioned on the ground . The sound coming from the sub
covers a shorter distance that the top in reaching the listener (position P), it is therefore necessary to delay the emission of the sub
to restore the correct temporal alignment . If d is the distance the subwoofer is placed in relation to the theoretical alignment position
(the dashed image in the picture), the delay to be set on the processor can be calculated using the following equation:
where c is the speed of sound (about 344 m/s) . The PC260 processor also allows the delay to be set directly in meters or feet .
Example: If the subwoofer is positioned 2 metres forward from the line of satellite units, the equation would work as follows:
d = 2 m T = d / c = 2 / 344 = 0.006 s = 6 ms
T
s
= d / c