I N S T A L L A T I O N ( c o n t i n u e d )
4.Using the Weco
the subwoofer(s) to the L and R (+ and
5.Make sure the wires are firmly seated in the Weco
6.Using Weco
NOTE: In
7. Make sure the wires are firmly seated in each Weco 4- pin connector and that each screw is completely tightened. Insert the wired Weco
8.Connect RCA cables from a source unit to the L /R, FRONT/REAR INPUT jacks. If the source unit has subwoofer outputs, also connect a pair of RCA cables from those jacks to the SUB INPUT jacks and set the SUB INPUT switch to EXT (see Figure 7).
S E T T I N G T H E C R O S S O V E R S . . .
1.To use the Kappa 255a in a front/rear system, set the CROSSOVER controls to frequencies recommended by the speaker manufacturer (see Figure 7). If the value is unknown, set the control midway.
2.For a
S E T T I N G I N P U T S E N S I T I V I T Y . . .
Initially, turn the front and rear input sensitivity GAIN controls to their minimum
1.Reconnect the
NOTE: After the source unit is on, green LEDs (on the top panel) will illuminate, indicating the amplifier is on. If not, check the wiring, especially the remote connection from the source unit. Also refer to “Troubleshooting” on the next page.
2.On the source unit, increase the volume control to maximum position. Slowly increase the Front and Rear GAIN controls (clockwise) towards three o’ clock and, at the same time, listen to the quality of the reproduced sound. At some point, you’ll hear distortion on the music peaks. Stop the adjustment and turn it back slightly.
S E T T I N G D B O . . .
Dynamic Bass Optimizer (DBO) is a new approach to enhancing
Since a subwoofer in a tuned box is given to overexcursion below the tuned frequency, set the FREQ control below the box’s resonant (tuned) frequency (see Figure 8 on the next page). Power typically wasted in this region will now be conserved and instead be available for frequencies the enclosure will reproduce. Use the Q control to boost the bass at the set frequency by as much as 12 dB (at MAX position – see Figure 8 on the next page).
For sealed enclosures, use DBO to enhance the output so it sounds more like a tuned box. This is a result of 12 dB of rolloff being added to the enclosure’s rolloff and a flattening
x15
x1
32Hz
320Hz
LP |
HP |
FLAT |
FRONT
C | 9V |
| G |
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| A | |
R |
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| I | |
O | .25V |
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S |
| N | |
S |
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| 32Hz |
V |
| M |
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E | BR |
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R |
| O | 320Hz |
O | ST | D | |
E | LP | ||
U |
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THP
UFLAT
| REAR |
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| SUBWOOFER | |
C | 9V |
| G | 9V | G |
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| A |
| A | |
R |
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S |
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O |
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V |
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E | BR |
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| 80Hz |
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O | MIN |
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E |
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U |
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T |
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P |
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U |
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T |
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| INT |
| SUB |
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| EXT |
| INPUT |
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| X | 32Hz |
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| O | 60 | |
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of frequency response (at the curve’s knee) when Q is boosted.
For infinite baffles, set the FREQ control to the speaker’s Fs value (to keep the subwoofer from trying to create bass below the resonant frequency) and adjust the Q control according to personal taste.
I N S T A L L I N G T H E C O N T R O L C O V E R . . .
After wiring and testing the Kappa 255a amplifier, install the control cover using the enclosed machine screws to deter tampering and help seal out dust.
NOTE: Do not
50W X 4
+
200W CLASS D
DIGITAL SUBWOOFER
AMPLIFIER
E |
| Hz |
R | 320Hz |
|
EXT | REAR | |
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FRONT LP | INPUT | |
|
crack the cover.
Figure 7. Kappa 255a controls for crossover, input, output, and DBO (Dynamic Bass Optimizer).
Owner’s Manual/Installation Guide – 7