SA-3051/SA-3052 Operation Manual
Crossover Testing
Our last application is crossover testing. Actually, this is just an extension of the setups used for compo-
nent checking. The setup is shown in Figure 5.7. You'll need the following items:
1. Two load resistors, resistance equal to the impedance rating of the crossover. 1 Watt power rating is suf-
ficient. You can also use the speakers that will be connected to the crossover as a load. If you're checking
an active crossover, you don't need the load resistors. Use the setup shown in Figure 5.8.
2. The SA-3051/SA-3052.
Figure 5.7. Checking a passive crossover
5-9
Figure 5.8. Checking an active crossover
It really doesn't matter which output you test first. Set the pink noise output of the SA-3051/SA-3052 at
maximum. Set the SA-3051/SA-3052 for a display reading about 3 LED's below the top of the display.
Use the 1 dB/step setting. Count three LED's down from the flat portion of the line shown on the display.
Move to the right or left until you intersect the falling portion of the line shown on the display. Now move
straight down to read the approximate crossover frequency. Store this reading in one of the memories.
Now repeat the operation for the other crossover output. Store this reading also. Now toggle between
the two memories. The two curves should look reasonably symmetrical (mirror images of each other).
Beware, however, some crossover designs are deliberately asymmetrical.
If you're using load resistors for testing, note that the load that is normally connected to the crossover
looks only vaguely like a resistor. It's a good idea to test crossovers both ways: using a dummy load resis-
tor (ideal conditions) and using the actual loudspeaker loads (real-world conditions).
