Earthquake Sound Down-Firing SUB 120 - Manual (Page 5)

This subwoofer is a "true subwoofer, it must never be operated above the subharmonic / harmonic frequency range. The
subwoofer frequency response is limited by the built-in crossover (with an upper end of 160 Hz); however, in most applications,
the crossover should not be set above 80Hz to 95Hz. It is equipped with a fourth- order Linkwitz-Riley filter which will block
vocals from interfering with its performance.
When setting up this subwoofer as a part of a home audio system, users must understand that the subwoofer requires
different settings: one for music, and one for playing movie tracks. In order to set up the subwoofer for music, users must
recognize the frequency response of their existing speakers (tower & surround sound) and the limitations of these speakers, i.e. the
diameter (size) of the speakers and the SPL.
For music setting:
1- Position the subwoofer in the corner of the living room.
2- Turn the unit around to expose the controls .
3- Turn on your audio system, and switch your surround sound
processor to "MUSIC" mode, and equalize the rest of your audio system.
4- Connect the subwoofer to the processor, using high quality (triple shielded) RCA cables.
5- Set the crossover to 150Hz - ma ximum position, volume at minimum (0).
6- Gradually raise the main volume knob ( between the 10 O'clock to 2 O'clock) position, optimizing for the subwoofer
performance. That is when the Optical Compression Circuitry works best, allowing the amp maximum output with minimal
distortion.
7- With the crossover open to 160Hz, you will hear vocals coming out of the subwoofer. Gradually reduce the crossover point until
vocals are eliminated (typical crossing point of 80Hz).
To control the volume level of the subwoofer, use the surround sound processor output controls; do not use the main
volume knob on the subwoofer (keep it between 10 & 2 O'Clock position). Once you set up the proper mix of low frequencies and
subharmonic response, that does not encroach on the rest of the speakers. Now you are ready to set up the subwoofer for home
theater use.
For movie viewing:
This subwoofer can be set up to your liking. There are no rules of thumb to how much bass is required. Often, users like to
feel the overwhelming bass, it brings the actions and events closer to real life. When viewing movies, a 10dB gain above music
setting is often pleasant, it brings movie viewing close to life.
If you desire to have a crossover setting for music, different than the setting for movie viewing. We suggest to cross the
subwoofer at higher frequency setting, and use the processor to control the desired lower crossing point.
VOLUME
40Hz 160Hz
CROSSOVER
FREQUENCY
24dB/Oct
Crossover knob in 2 O'clock position - 90Hz @ -3dB.
0.0
-1.0
-2.0
-3.0
-4.0
-5.0
-6.0
-7.0
-8.0
-9.0
+1.0
+2.0
+3.0
+4.0
+5.0
+6.0
+7.0
+8.0
+9.0
10 20 30 40 50 60 70 80 90 100 200Hz
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VOLUME
40Hz 160Hz
CROSSOVER
FREQUENCY
24dB/Oct
Crossover knob in 1 O'clock position - 85Hz @ -3dB.
0.0
-1.0
-2.0
-3.0
-4.0
-5.0
-6.0
-7.0
-8.0
-9.0
+1.0
+2.0
+3.0
+4.0
+5.0
+6.0
+7.0
+8.0
+9.0
10 20 30 40 50 60 70 80 90 100 200Hz
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-5-
Setting Up Your Subwoofer.