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 2K
Ω
. 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% RESISTORS
1 dB
82 K
82,5 K
2 dB
39 K
38,3 K
3 dB
24 K
24,3 K
4 dB
18 K
16,9 K
5 dB
13 K
13 K
6 dB
10 K
10 K
7 dB
8,2 K
8,06 K
8 dB
6,8 K
6,65 K
9 dB
5,6 K
5,62 K
10 dB
4,7 K
4,64 K
11 dB
3,9 K
3,92 K
12 dB
3,3 K
3,32 K
13 dB
3 K
2,87 K
14 dB
2,4 K
2,49 K
15 dB
2,2 K
2,21 K
24
