Polk Audio PA250.2 owner manual Crossover Settings Gain Adjustment, LED Tube Installation Optional

CROSSOVER SETTINGS

AND GAIN ADJUSTMENT

Your Polk Audio power amplifier needs to be adjusted carefully to achieve maximum performance. These are some guidelines to follow when fine-tuning the amplifier.

•For full-range and simultaneous stereo/mono bass applications, the crossover selection switch should be set to FULL. If the amplifier is driving your sub- woofers, set the switch to LOW, and for mid-bass/ midrange output, set to HIGH.

•The crossover frequency control needs to be adjusted to suit your particular system. For subwoofer appli- cations, try and keep the setting low enough to prevent image smearing (you should not be able to hear male voices from the subwoofer) but not so low as to create a gap between the subwoofer and the mid-bass/ midrange speakers. For mid-bass/midrange settings, try to keep the setting low enough to keep your sound stage in front of you, without overdriving the speaker. It will be to your advantage to spend some extra time with this adjustment, listening to familiar music or system set-up discs to achieve the kind of musical reproduction that you prefer.

•The gain adjustment allows you to set proper signal match for clean, quiet amplifier operation. For full-range and simultaneous stereo/mono bass applications, start by playing some music you are familiar with. With the gain adjustment on the amplifier in the middle of its rotation, bring up the volume on your head unit to the 3/4 volume setting or until you start to hear distortion or clipping. If you hear distortion before you reach the 3/4 volume setting of your head unit, reduce the gain setting on the amplifier and start to raise the head unit

volume again. When you can listen to the music at or slightly above 3/4 on your head unit without audible distortion, slowly raise the gain of the amplifier until distortion is heard, then back off the gain until the distortion is not audible. This setting will allow you to reach full output with all but the quietest of source material, while avoiding excessive noise in the system.

NOTE: Polk amplifiers use a digital gain control with

a finite number of adjustment steps. A very small adjust- ment may not cause any audible change in level.

LED TUBE INSTALLATION (OPTIONAL)

These Polk Audio amplifiers have been designed with a custom heat sink that can accommodate two (optional—not supplied) VARAD LED tubes.

1.Before installing the LED tubes, remove and discard the mounting feet from the VARAD LED tubes.

2.Slide each LED tube assembly into your Polk Audio amplifier heat sink. Ensure that the LEDs are facing out for optimal visibility. The wires from the LED tube assembly should be on the signal input end of the amplifier. The Black wire from the LED tube is ground and the Black/White wire from the LED tube is power.

3.Run the two wires from the tube assembly and connect them to the 4-pin LED/FAN input connec- tor. Refer to the LED/FAN harness diagram given earlier in this manual.

NOTE: If the optional fan IS NOT being used, we recom- mend that the second LED tube be wired to this circuit. If the optional fan is being used, we recommend that the second LED tube be wired in parallel with the first LED tube.

ENGLISH

CEA SPECIFICATIONS

PA250.2 Power Output: 90 Watts RMS x 2 channels at 4 Ohms and ≤ 1% THD+N

Signal to Noise Ratio: -70 dBA (reference 1 Watt into 4 Ohms)

Additional Power: 125 Watts RMS x 2 channels at 2 Ohms and ≤ 1% THD+N

SPECIFICATIONS	PA250.2
Dynamic Power Rating @ 2 Ohms	200W x 2
RMS Continuous Power @ 2 Ohms2	125W x 2
RMS Continuous Power @ 4 Ohms1	90W x 2
RMS Continuous Power	250W x 1
Bridged 4 Ohms3
Signal-to-Noise Ratio	Greater than 90 dB
Frequency Response	20-20,000 Hz + 0.25 dB
Damping Factor	Greater than 100
Crossover	Switchable high or low pass
	12dB/octave, 100Hz
Bass Equalization	+8 dB, centered at 40Hz
(Variable or Fixed)
Input Impedance	20K Ohms
Input Sensitivity	Variable from
	250 mV to 7.5 volts
Output Impedance	2 to 8 Ohms, stereo
	4 to 8 Ohms, bridged
Supply Voltage	10 to 16 VDC
Fusing and Power/Type	30A
Minimum Cable Requirements	#10
(AWG) (Per amp, Trunk Mounted)

1RMS continuous power driven into 4 Ohms from 20 to 20,000 Hz @ 14.4VDC with less than 0.08% THD+N.

2 RMS continuous power driven into 2 Ohms from 20 to 20,000 Hz @ 14.4VDC with less than 0.15% THD+N.

3 RMS continuous power bridged into 4 Ohms from 20 to 20,000 Hz @ 14.4VDC with less than 0.15% THD+N.

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