PA250.2 21 CHANNELS - Amplifier POLK AUDIO - Free user manual and instructions

USER MANUAL PA250.2 21 CHANNELS POLK AUDIO

ENGLISH ENGLISH WARNING High-powered car audio systems may produce sound pressure levels that exceed the threshold at which hearing loss may result. They may also impair a driver’s ability to hear traffic sounds or emergency vehicles. Use common sense and practice safe listening habits when listening to or adjusting your audio system.

GETTING STARTED Take Inventory Check to ensure you have everything in your Polk Audio amplifier carton to start enjoying your system. Inside, you should find:

1. Polk Audio Amplifier (PA250.2)

2. Phillips Screws (4)

3. Mounting Washers (4)

• Read this manual thoroughly before you begin. FEATURES

4. Locking Washers (4)

• High-speed MOSFET switching power supply and complementary bi-polar outputs.

• Thermal, DC offset, reverse polarity.

• Take steps to protect your car and upholstery from unwanted scratches and punctures.

• Selectable 12dB/octave two-way crossover.

• Wear proper protective safety gear.

• Switchable 8dB bass EQ function.
• Variable input sensitivity optimizes match with different signal sources.
• Chrome-plated wire terminals and RCA connectors ensure maximum signal transfer.
• Rugged extruded heatsink and cover.
• Unity gain pass-through RCA jacks. Important Note: If anything is missing or damaged, or if your Polk Audio amplifier fails to operate, notify your dealer immediately. We recommend keeping your original carton and packing materials in case you need to ship the unit in the future.

• Plan your installation carefully.
• Allow enough time to complete the installation without rushing.

• Phillips head screwdriver
• Electric drill and 3/16" and 1/8" drill bits
• Permanent ink marker or pencil In the event that your amplifier requires service or is ever stolen, you will need to have a record of the product’s serial number. Please take the time to enter that number in the space provided below. The serial number can be found on the bottom panel of the amplifier and on the amplifier packaging.

Installing a car audio system is a serious project. If you have any doubts about your ability to execute any of the installation steps found in this manual, save yourself a lot of grief and contact a professional installer. Your Polk Audio dealer is a good place to find one. If you intend to do the installation yourself we assume you possess some skill in the proper use of hand and power tools. No matter how much installation experience you have, we recommend that you…

• Solderless, crimp-on connectors and a crimping tool
• Wire strippers and cutters Automobile horsepower is good analogy. Your car probably has far more horsepower than it needs for your daily commute and is likely capable of going well over 120 MPH (190KM/hr). Having that extra power is good for on-ramp acceleration and danger avoidance (like getting away from brain-eating zombies) but that doesn’t mean that it is advisable to operate your car on North American highways at full power and maximum speed for an extended period of time. Just ask your local state trooper if you are in doubt. Similarly, we recommend using amplifiers and receivers with rated power above the Power Handling limits of our speakers because having extra power available for short terms peaks is conducive to better sound quality, maximum dynamic range and effortless high volume output. But we strongly urge you not to use the full power of your amp or receiver for daily listening. Loudspeakers can be damaged when an amplifier, regardless of its wattage, is made to play at higher listening levels than its power can clearly produce. Operation at this level can result in very high levels of audible distortion originating in the amplifier, which can add a harsh, gritty sound to your listening material. If you hear distortion—turn the volume down or risk damaging your speakers. You can damage just about any speaker, regardless of power rating, if you drive an amplifier to or beyond the point of distortion. INSTALLATION GUIDELINES

1. Please read this owner’s manual carefully before

installing this amplifier.

2. Disconnect the battery ground terminal prior

to making any electrical connections.

• Amplifier Power Wire Kit (available at your authorized Polk Audio Dealer)

3. Check for any hazards or obstructions such as gas

tanks, fuel or brake lines, and wiring harnesses before mounting the amplifier.

SAFE LIMITS OF OPERATION

4. Pick a mounting location that will provide adequate

access and ventilation and protect the amplifier from heat, moisture, and dirt. Polk Audio specifies the recommended amplification range for each of its passive (non-amplified) loudspeakers. Typically that specification will be expressed as a range of power such as 20-200 Watts (per channel). It is important to understand what those numbers mean when choosing a receiver or amplifier for your Polk loudspeakers. The lower number indicates the lowest continuous rated power that will yield acceptable performance in a typical listening environment. The higher number indicates the highest per channel power that should be used with your Polk speakers. That number should not be confused with a “Power Handling” specification and it does not imply that the speaker will safely handle that full amount of power on a long-term basis. We specify a wide range of power ratings because not all electronics manufacturers use the same method for rating power. In fact, high quality lowerrated amplifiers sound better and play louder than low quality units with higher power rating.

5. To securely mount your amplifier you must first remove

the top cover assembly. Unscrew the four (4) top cover assembly retaining screws.

6. Avoid sharp metal areas when routing cables to the

amplifier, and run RCA cables away from the power cables and other potentially noisy car harnesses.

7. The amplifier should be grounded with a short, heavy

gauge wire connected directly to the car at a bare metal surface, preferably scraped body sheet metal. Do not use factory ground locations, seat bolts, or brackets that are spot welded.

8. Always fuse your power connection within 8 to 10 inches

of the battery terminal. Use a fuse or circuit breaker rated slightly more than the on-board fuse(s) of the amplifier(s). The gauge of power wire used should take into account the total current draw of the system, and the length of

WWW.POLKAUDIO.COM/AMPS

ENGLISH wire used. IASCA and other auto sound competition organizations have charts available for this; you can also find a chart in the MECP study guide. Minimum wire gauge recommendations for the individual amplifiers are listed on the specification page. Always use the same gauge wire for the amplifier ground that you use for the power wire. Be sure to examine the battery ground cable of the vehicle, and if necessary, upgrade it by adding an additional ground wire that is the same gauge as the amplifier’s power wire. Remember, the amplifier can only deliver its rated output when it is not current limited by the power and ground supply wires.

9. This amplifier is designed to drive a speaker load

that measures from 2 to 8 ohms. Keep in mind that heat is the long-term enemy of automotive electronics and the lower your speaker load, the more heat is generated. For low-impedance speaker applications or restricted ventilation installations, an external cooling fan may be advisable.

10. Battery and ground connections to the vehicle should

be made with crimped ring terminals of the appropriate size (surface area is what counts;) soldering the terminals after crimping is also recommended.

11. Due to the high-frequency MOSFET switching power

supply, filtering the power cable is not generally required (remember that the amp can’t deliver full output if the power supply is restricted.) Proper grounding of the signal source is mandatory for the amplifier to reach its performance peak. If the RCA inputs are not grounded adequately via the signal source, electrical noise from the vehicle may be picked up in the system. FIGURE 1—AMPLIFIER CONNECTIONS/CONTROLS—FRONT (PA250.2)

REAR PANEL CONNECTIONS

1. Fuse—These fuses protect the amplifier against

internal electrical damage and are meant to protect the amplifier only. All other power connections should be fused at the source.

2. (+) 12 Volt Power—Connect this terminal through

a FUSE or CIRCUIT BREAKER to the positive terminal of the vehicle battery or the positive terminal of an isolated audio system battery.

WARNING: Always protect this power wire by installing a fuse or circuit breaker of the appropriate size

within 12 inches of the battery terminal connection.

3. Remote Turn On—This terminal turns on the amplifier

when (+) 12 volt is applied to it. Connect it to the remote turn on lead of the head unit or signal source.

4. Ground—Connect this terminal directly to the sheet

metal chassis of the vehicle, using the shortest wire necessary to make this connection. Always use wire of the same gauge or larger than the (+) 12 volt power wire. The chassis connection point should be scraped free of paint and dirt. Use only quality crimped and/or soldered connectors at both ends of this wire. DO NOT connect this terminal directly to the vehicle battery ground terminal or any other factory ground points.

5. Speaker Terminals—Connect subwoofers to these

terminals. (Refer to the Speaker Wiring Diagrams section of this guide.) FIGURE 3—AMPLIFIER CONNECTIONS—REAR (PA250.2)

FRONT PANEL CONNECTIONS/CONTROLS

1. RCA Input Jacks—Accepts line level outputs from

head units or signal processors at voltages between 250mV and 7.5 volts.

2. RCA Line Output Jacks—These pass-through

RCA jacks can be used to send the input signal to a second amplifier.

3. Gain Control—Controls the amplifier’s sensitivity

and is used to match the input level of the amplifier to the output level of the signal source.

4. Bass EQ Switch—Adds 8dB additional bass boost

to the speaker output when on.

5. X-Over Selection Switch (HPF, Flat, LPF)—

The HPF attenuates low frequencies and is used with mid-range speakers and tweeters. Flat does not attenuate any frequencies and is for full range speaker systems. LPF attenuates high frequencies and is used for subwoofers.

6. Light Bar/FAN—Allows connection of an optional

LED light bar or optional cooling fan for the amplifier.

amplifier is on and operating normally, and will be illuminated RED if the amplifier shuts down due to short circuit, DC offset, or overheating detected by onboard protection circuitry.

ENGLISH FIGURE 4—SPEAKER WIRING DIAGRAMS (PA250.2) Passive Tri-Mode*/Mono Operation (top view) I N D Inductor UCTOR Sub SUB Left L CH Channel Left L CH Channel Cap C A P Right Channel R CH B r Bridged idged CCap

Stereo Operation (top view) Right R CH Channel NOTE: For bridged two channel operation as shown in this diagram, connect right channel RCA cables to the front inputs of the amplifier, and left channel RCA cables to the rear inputs of the amplifier. For summed subwoofer applications, connect RCA cables per the input jack marking. *Consult your loudspeaker manufacturer for recommended inductor and capacitor values. Left L CH Channel Right Channel R CH

B r Bridged idged Mono Operation (top view)

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 subwoofers, 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 applications, 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. CEA SPECIFICATIONS 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 PA250.2 NOTE: Polk amplifiers use a digital gain control with a finite number of adjustment steps. A very small adjustment 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 connector. Refer to the LED/FAN harness diagram given earlier in this manual. 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 Bridged 4 Ohms3 250W x 1 Signal-to-Noise Ratio Greater than 90 dB Frequency Response 20-20,000 Hz +_ 0.25 dB Damping Factor Crossover NOTE: If the optional fan IS NOT being used, we recommend 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. Greater than 100 Switchable high or low pass 12dB/octave, 100Hz Bass Equalization (Variable or Fixed) +8 dB, centered at 40Hz Input Impedance 20K Ohms Input Sensitivity Output Impedance Supply Voltage Variable from 250 mV to 7.5 volts 2 to 8 Ohms, stereo 4 to 8 Ohms, bridged 10 to 16 VDC Fusing and Power/Type 30A Minimum Cable Requirements (AWG) (Per amp, Trunk Mounted) #10 RMS continuous power driven into 4 Ohms from 20 to 20,000 Hz @ 14.4VDC with less than 0.08% THD+N. RMS continuous power driven into 2 Ohms from 20 to 20,000 Hz @ 14.4VDC with less than 0.15% THD+N. RMS continuous power bridged into 4 Ohms from 20 to 20,000 Hz @ 14.4VDC with less than 0.15% THD+N.