Equalizer Card Configuration; Gain Calculation - Altair FA-524 Owner's Manual

EQUALIZER CARD CONFIGURATION:

The next picture shows the component overlay of an equalizer card. As seen in the
picture, there are 6 resistors called RG+, RG-, RQ, RQ,' RF and RF' . This resistors define the
gain (RG+ or RG-), the bandwidth (RQ and RQ') and the center frequency (RF and RF') of the
equalization point:
Before adjusting a equalizer card, you should decide the gain, bandwidth and center
frequency that you want to implement, for this could use a parametric equalizer or a graphic
equalizer and the results will be verified with a spectrum analyzer. The use of a parametric
equalizer is more advisable since the adjustment parameters coincide with the equalizer
card one. Keep in mind if you use a graphic equalizer that could introduce only two points of
equalization for way, because of that don't use a lot of equalizer bands.

GAIN CALCULATION:

There are two resistors in the equalizer card, called RG+ and RG- that configure the
equalization point gain. For the gain you should only place a resistor, if you want positive
gains should place it in RG+, and if you want gains negatives should place it in RG-.
The maximum gain of the equalization point is of 15 dB, since this resistor could not
be less than 2KΩ. If you want unitary gain don't place any resistance.
The next table shows the resistors that you should use for gains between 1 and 15 dB,
in 1 dB steps. If you want an intermediate gain you are able to calculate an intermediate
value:
GAIN 5% RESISTORS
1 dB 82 K
2 dB 39 K
3 dB 24 K
4 dB 18 K
5 dB 13 K
6 dB 10 K
7 dB 8,2 K
8 dB 6,8 K
9 dB 5,6 K
10 dB 4,7 K
11 dB 3,9 K
12 dB 3,3 K
13 dB 3 K
14 dB 2,4 K
15 dB 2,2 K
1% RESISTORS
82,5 K
38,3 K
24,3 K
16,9 K
13 K
10 K
8,06 K
6,65 K
5,62 K
4,64 K
3,92 K
3,32 K
2,87 K
2,49 K
2,21 K
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