HSU ULS-15, Руководство пользователя

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7
Using the CDR to Fine Tune
You can use the test tones on the CDR we provide to fine tune the subwoofer. 80 Hz is the crossover frequency used for thise example:
1. Play the 50 Hz test tone.
2. Adjust the volume on the controller to get 80 dB reading on the SPL meter placed at the listening chair.
3. Play tones from 32 Hz up to 200 Hz. Note the SPL reading on the meter at each frequency.
4. Take the average of the four tones below 80 Hz: – 63, 50, 40 and 32 Hz.
5. Take the average of the four tones above 80 Hz:. – 100, 125, 160 and 200 Hz.
6. If the average of the four tones below 80 Hz is, say, 5 dB higher than the average of the upper range, adjust the subwoofer level down 5 dB.
7. If your controller has a subwoofer out level, use this to adjust the level. If it does not, play the 50 Hz tone and adjust the subwoofer
volume control to get the desired change in level.
If you are using the Radio Shack SPL meter, compensate for the meter’s deep bass deficiency. The older analog Radio Shack meters are
down 12 dB at 16 Hz, 7 dB at 20 Hz, 4 dB at 25 Hz, and about 2 dB down at 32 Hz. Add these numbers to the actual readings you get
from the meter. The newer digital meters are off even more. Add at least 2 dB to the above numbers.
Equalizing the Subwoofer
Some controllers have built-in equalizers for the subwoofer channel. You can use these to reduce the major room modes (peaks). It is gen-
erally not recommended to boost bass to compensate for nulls (dips) as this will use up too much power and risk damaging the subwoofer.