JL Audio A1800 User's Manual
Contents
1. 6 AWG wire to ground the battery to the vehicle s chassis and to connect the alternator to the battery To prevent voltage drops these wires should be upgraded to 4 AWG when installing amplifier systems with main fuse ratings above 60A Grounding problems are the leading cause of misdiagnosed amplifier failures My amplifier turns on but there is no output Check the input signal using an AC voltmeter to measure the voltage from the source unit while an appropriate test tone is played through the source unit disconnect the input cables from the amplifier prior to this test The frequency used should be in the range that is to be amplified by the amplifier example 50 Hz for a sub bass application or 1 kHz for a full range high pass application A steady sufficient voltage between 0 2 and 8 0 volts should be present at the output of the signal cables Check the output of the amplifier Using the procedure explained in the previous check item after plugging the input cables back into the amplifier test for output at the speaker outputs of the amplifier Unless you enjoy test tones at high levels it is a good idea to remove the speaker wires from the amplifier while doing this Turn the volume up approximately half way 5V or more should be measured at the speaker outputs This output level can vary greatly between amplifiers but it should not be in the millivolt range with the source unit at half volume If you are rea2. expose the amplifier circuitry to the elements JL AUDIO A1800 PRODUCT DESCRIPTION The JL Audio A1800 is a monoblock subwoofer amplifier utilizing proprietary and patented Class D technology Its frequency response is limited to the range below 250 Hz It is not designed for driving midrange speakers or tweeters Every aspect of its operation has been optimized for low frequency amplification For detailed specifications please refer to Appendix C page 13 TYPICAL INSTALLATION SEQUENCE The following represents the sequence for a typical amplifier installation using an aftermarket source unit or OEM Interface processor like the CleanSweep CL441dsp Additional steps and different procedures may be required in some applications If you have any questions please contact your authorized JL Audio dealer for assistance 1 Disconnect the negative battery post connection and secure the disconnected cable to prevent accidental re connection during installation This step is not optional 2 Run power wire minimum 4 AWG from the battery location to the amplifier mounting location taking care to route it in such a way that it will not be damaged and will not interfere with vehicle operation Use 2 AWG or 1 0 AWG power wire and a power distribution block if additional amplifiers are being installed with the A1800 3 Connect power wire to the positive battery post Fuse the wire with an appropriate fuse block and connectors
3. 43 1100 9 00 AM 5 30 PM Eastern Time Zone Monday Friday JL AUDIO A1800 11 APPENDIX A Input Sensitivity Level Setting Following the directions below will allow the installer to adjust the input sensitivity of each amplifier channel pair simply and easily in just a few minutes using equipment which is commonly available in installation bays Necessary Equipment e Digital AC Voltmeter e CD with a sine wave test tone recorded at 0 dB reference level in the frequency range to be amplified for that set of channels 50 Hz for subwoofer channels 1 kHz for a midrange application Do not use attenuated test tones 10 dB 20 dB etc The Nine Step Procedure 1 Disconnect the speaker s from the amplifier s speaker output connectors 2 Turn off all processing bass treble loudness EQ etc on the source unit processors if used and amplifier Set fader control to center position and subwoofer level control to 3 4 of maximum if used to feed the A1800 3 Switch the Input Voltage switch to Low and turn the Input Sens control all the way down 4 Set the source unit volume to 3 4 of full volume This will allow for reasonable gain overlap with moderate clipping at full volume 5 Using the chart on this page determine the target voltage for input sensitivity adjustment according to the nominal impedance of the speaker system connected to the amplifier outputs 6 Verify that you have dis
4. 98 APPENDIX C A1800 Specifications General Specifications Recommended Fuse Value 80A Recommended Fuse Type AGU AFS ANL or MaxiFuse Input Sections No of Inputs One Stereo Pair Input Type Differential balanced with RCA jack inputs Input Range Switchable from 200mV 2V RMS to 800mV 8V RMS Amplifier Section Amplifier Topology H Bridge Class D Mono with patented discrete drive circuitry Power Supply Unregulated MOSFET switching type Rated Power at 12 5 V with less than 0 08 THD Noise 20 250 Hz 480W RMS x 1 4 ohms 800W RMS x 1 2 ohms Rated Power 14 4V with less than 1 THD Noise 20 250 Hz 640W RMS x 1 4 ohms 1000W RMS x 1 2 ohms Signal to Noise Ratio gt 95 dB referred to rated power A weighted 20 Hz 20 kHz noise bandwidth Frequency Response 10 250 Hz 0 1 dB Damping Factor gt 500 4 ohms 50 Hz gt 250 2 ohms 50 Hz Amplifier Filter Amplifier Low Pass Filter State variable 12 dB octave Butterworth or 24 dB octave Linkwitz Riley with continuously variable cutoff frequency selection from 40 200 Hz Defeatable Preamp Output Buffered pass through type Dimensions LxWxH 15 75 x 9 25 x 2 50 400mm x 235mm x 63 5mm Due to ongoing product development all specifications are subject to change without notice JL AUDIO A1800 13 APPENDIX D TROUBLE SHOOTING How do I properly set the input sensitivity on my amplifier Please refer to Appendi
5. A1800 monoblock subwoofer amplifier OWNER S MANUAL Thank you for purchasing a JL Audio amplifier for your automotive sound system Your amplifier has been designed and manufactured to exacting standards in order to ensure years of musical enjoyment in your vehicle For maximum performance and extended warranty coverage we highly recommend that you have your new amplifier installed by an authorized JL Audio dealer Your authorized dealer has the training expertise and installation equipment to ensure optimum performance from this product Should you decide to install the amplifier yourself please take the time to read this manual thoroughly so as to familiarize yourself with its installation requirements and setup procedures If you have any questions regarding the instructions in this manual or any aspect of your amplifier s operation please contact your authorized JL Audio dealer for assistance If you need further assistance please call the JL Audio Technical Support Department at 954 443 1100 during business hours PROTECT YOUR HEARING We value you as a long term customer For that reason we urge you to practice restraint in the operation of this product so as not to damage your hearing and that of others in your vehicle Studies have shown that continuous exposure to high sound pressure levels can lead to permanent irreparable hearing loss This and all other high power amplifiers are capable of producing such
6. WG then 8 AWG etc To connect the power wires to the amplifier first back out the set screw on the top of the terminal block using the supplied 2 5 mm hex wrench Strip 1 2 inch 12 mm of insulation from the end of each wire and insert the bare wire into the terminal block seating it firmly so that no bare wire is exposed While holding the wire in place tighten the set screw firmly taking care not to strip the head of the screw The ground connection should be made using the same gauge wire as the power connection 4 AWG and should be kept as short as possible while accessing a solid piece of sheet metal in the vehicle The surface of the sheet metal should be sanded at the contact point to create a clean metal to metal connection between the chassis and the termination of the ground wire For optimal grounding we recommend the use of a JL Audio ECS master ground lug XA MGL 1 Alternatively a sheet metal screw or bolt can be used with a star washer Any wires run through metal barriers such as firewalls must be protected with a high quality rubber grommet to prevent damage to the insulation of the wire Failure to do so may result in a dangerous short circuit Eq IMPORTANT Many vehicles employ small 10 AWG 6 AWG wire to ground the battery to the vehicle chassis and to connect the alternator s positive connection to the battery To prevent voltage drops these wires should be upgraded to 4 AWG when ins
7. at from the amplifier circuitry For optimum cooling performance this outer shell should be exposed to as large a volume of air as possible Enclosing the amplifier in a small poorly ventilated chamber can lead to excessive heat build up and degraded performance If an installation calls for an enclosure around the amplifier we recommend that this enclosure be ventilated with the aid of a fan In normal applications fan cooling is not necessary Connector pg 5 12V Power Remote Turn On Speaker Outputs Connector Connector pg 8 pg 5 pg 6 JL AU DIO 12VDC Ground Remote O Speaker Output Mono min 2 0 ey B Input Voltage Left amp Right Protection Status Bass EQ Filter Mode Selection Preamp Output Jacks Indicator On Off Switch Selection pg 6 pg 8 pg 9 Jack for pg 8 pg 7 Left amp Right _ Power Status Remote Bass Input Sensitivity Filter a Preamp Input Jacks Indicator Control Knob Control Frequency Selector a pg 6 at E pg 8 a pg 6 pg 7 f AL W Do z SZ wm lifier Inputs CH 1 Left Pre Outs Amplifier Status Bass Boost Controls Amplifier Controls Fiker Freq a AS Z Input Voltage O O Bass Boost D Sens Filter mM fe ae M mm 200 Low High QQ CH2 Right Amp
8. c Class D design BASS BOOST CONTROLS AUDIO Status Bass Boost Controls Bass Boost Protect M off on Remote sgasae gafot out signals stereo 1 Bass Boost This switch allows the user to activate a 6 dB boost centered at 48 Hz The Filter Mode switch in the Amplifier Controls section must be in the LP position for the bass boost to be functional 2 Remote Bass Port This port allows you to connect an optional remote boost knob sold separately JL Audio Model RBC 1 that can be mounted in the front of the vehicle With the RBC 1 connected the boost is no longer limited to 0 or 6 dB allowing a range of 0 12 dB of boost to be selected PRE OUTS The A1800 incorporates a pass through preamp output section so that additional amplifiers can be easily added to the system The preamp output delivers the same signal that is connected to the A1800 s inputs CH1 Left Pre Outs Amp Amplifier always st Buffered remi CH2 Right JL AUDIO A1800 The preamp output signal is not affected by the Bass Boost processing selected for the amplifier or by any crossover filter selected if the input signal is full range the preamp output will be full range The signal level of the Preamp Output is line level low voltage regardless of the position selected via the A1800 s Input Voltage switch An additional amplifier connected
9. connected the speakers before proceeding Play a track with an appropriate sine wave within the frequency range to be amplified by the A1800 at 3 4 source unit volume 7 Connect the AC voltmeter to the speaker output connectors of the amplifier Make sure you test the voltage at the correct connectors and 8 Increase the Input Sens control until the target voltage is observed with the voltmeter 9 Once you have adjusted the A1800 to its maximum low distortion output level reconnect the speaker s The Input Sens controls can now be adjusted downward if the amplifier requires attenuation to achieve the desired system balance IMPORTANT Do not increase any Input Sens setting for any amplifier channel or channel pair in the system beyond the maximum level established during this procedure Doing so will result in audible distortion and possible speaker damage It will be necessary to re adjust the Input Sens for the affected channels if any equalizer boost is activated after setting the Input Sens with this procedure This applies to any EQ boost circuit including source unit tone controls or EQ circuits EQ cuts will not require re adjustment Nom Impedance Target AC Voltage 12 JL AUDIO A1800 APPENDIX B Precise Frequency Selection Chart FILTER FREQ AMP FILTER Detent Panel Actual Number Marking Freq Full counter clockwise 42 Full clockwise 1
10. d The amplifier will continue to operate and return to normal power output once its temperature returns to a normal range Low Voltage protection If the car s supply voltage drops below 10 volts the entire amplifier will shut itself off to protect its internal circuitry The green Power indicator will turn off when this occurs The amplifier will turn back on when voltage climbs back above 10 volts This may happen in a rapid cycle when bass heavy program material causes a weak charging system to dip below 10 volts momentarily If this is happening in your system turn your audio system off and have your power wiring ground connections and charging system inspected 10 JL AUDIO A1800 SERVICING YOUR JL AUDIO AMPLIFIER If your amplifier fails or malfunctions please return it to your authorized JL Audio dealer so that it may be sent in to JL Audio for service There are no user serviceable parts or fuses inside the amplifier The unique nature of the circuitry in the JL Audio amplifiers requires specifically trained service personnel Do not attempt to service the amplifier yourself or through unauthorized repair facilities This will not only void the warranty but may result in the creation of more problems within the amplifier If you have any questions about the installation or setup of the amplifier not covered in this manual please contact your dealer or technical support JL Audio Technical Support 954 4
11. ding sufficient voltage check your speaker connections as explained below Check to ensure that the speaker wires are making a good connection with the metal inside the terminal block The speaker wire connectors are designed to accept up to 8 AWG wire Make sure to strip the wire to allow for a sufficient connection with the metal inside the terminal block JL AUDIO A1800 15 INSTALLATION NOTES Use this diagram to document your amplifier s switch and control positions JL DIO role Inputs Input Voltage LH Low High CH 1 Left CH 2 Right Pre Outs Amplifier Status O O Power Protect Amplifier input signals are always summed to mono Buffered pre out signals remain in stereo Bass Boost Controls Remote Bass Port Bass Boost LL off On Amplifier Controls Filter Fed FR Input Sens iaa Filter AL 12dB 24dB 40 200 16 JL AUDIO A1800 JL AUDIO A1800 TZ INSTALLATION NOTES 18 JL AUDIO A1800 INSTALLATION NOTES JL AUDIO A1800 19 LIMITED WARRANTY AMPLIFIERS USA JL AUDIO warrants this product to be free of defects
12. e source unit at a low level to double check that the amplifier is configured correctly Resist the temptation to crank it up until you have verified the control settings 15 Make necessary adjustments to the input sensitivity controls to obtain the right overall output and the desired balance in the system See Appendix A page 12 for the recommended input sensitivity setting method 16 Enjoy the fruits of your labor with your favorite music JL AUDIO A1800 POWER CONNECTIONS Before installing the amplifier disconnect the negative ground wire from the vehicle s battery This will prevent accidental damage to the system the vehicle and your body during installation 12VDC Ground Remote O The A1800 s 12VDC and Ground connections are designed to accept 4 AWG power wire 4 AWG is a minimum power wire size for this amplifier If you are installing the A1800 with other amplifiers and wish to use a single main power wire use 2 AWG or larger main power wire for systems with total power between 700W and 1400W or 1 0 AWG wire for systems with more than 1400W This main power wire should terminate into a distribution block mounted as close to the amplifiers as possible The output of the distribution block will connect to the A1800 with 4 AWG power wire Note that smaller AWG numbers mean bigger wire and vice versa 1 0 AWG is the largest 2 AWG is smaller then 4 A
13. f wires connected to a test speaker Check the nominal load impedance to verify that of the amplifier is driving a load equal to or greater than 2 ohms Check the input signal and input signal cables to make sure signal is present at the Amplifier Inputs and the cables are not pinched or loose It may be helpful to try a different set of cables and or a different signal source to be sure My ampilifier s output fluctuates when I tap on it or hit a bump Check the connections to the amplifier Make sure that the insulation for all wires has been stripped back far enough to allow a good contact area inside the terminal block Check the input connectors to ensure that they all are making good contact with the input jacks on the amplifier 14 JL AUDIO A1800 My amplifier shuts off once in a while usually at higher volumes Check your voltage source and grounding point The power supply of the A1800 will operate with charging system voltages down to 10V Shutdown problems at higher volume levels can occur when the charging system voltage drops below 10V These dips can be of very short duration making them extremely difficult to detect with a common DC voltmeter To ensure proper voltage inspect all wiring and termination points It may also be necessary to upgrade the ground wire connecting the battery to the vehicle s chassis and the power wire connecting the alternator to the battery Many vehicles employ small 10 AWG
14. from the 12 dB octave slope which lets more upper bass content pass through A sub that fires directly into the listening environment is more likely to benefit from a 24 dB octave slope Note The above hint is not set in stone You should always listen to the system carefully to determine the best choice as vehicle acoustics and other factors play a big role in choosing the most appropriate filter slope 3 Precise Frequency Selection The filter frequency markings on the front panel of the amplifier are for reference purposes and are generally accurate to within 1 3 octave or better If you would like to select the filter frequency with a higher level of precision consult Appendix B page 13 of this manual This chart gives you a more accurate frequency for each of the forty detented positions of the frequency selection control This method can be very useful if the amplifier is mounted in a location where you can t see the front panel markings easily 4 Defeating the Amplifier Filter The Low Pass filter can also be defeated completely by switching the Mode Slope switch to the Off position This is useful if you are using an external active crossover in the system Keep in mind that turning the internal crossover off also defeats the Bass Boost processing see next section for details With the internal crossover turned off the A1800 s upper frequency response limit is 250 Hz due to its bass specifi
15. herefore these exclusions may not apply to you This warranty gives you specific legal rights and you may also have other rights which vary from state to state If you need service on your JL AUDIO product All warranty returns should be sent to JL AUDIO s Amplifier Service Facility freight prepaid through an authorized JL AUDIO dealer and must be accompanied by proof of purchase a copy of the original sales receipt Direct returns from consumers or non authorized dealers will be refused unless specifically authorized by JL AUDIO with a valid return authorization number Warranty expiration on products returned without proof of purchase will be determined from the manufacturing date code Coverage may be invalidated as this date is previous to purchase date Non defective items received will be returned freight collect Customer is responsible for shipping charges and insurance in sending the product to JL AUDIO Freight damage on returns is not covered under warranty For Service Information in the U S A please call JL Audio Customer Service 954 443 1100 9 00 AM 5 30 PM Eastern Time Zone JL Audio Inc 10369 North Commerce Pkwy Miramar FL 33025 do not send product for repair to this address International Warranties Products purchased outside the United States of America are covered only by that country s distributor and not by JL Audio Inc Patented Class D Amplifier Circuit U S Patent 6 441 685 is Patent Pending i
16. high sound pressure levels when connected to a speaker system Please limit your continuous exposure to high volume levels While driving operate your audio system in a manner that still allows you to hear necessary noises to operate your vehicle safely horns sirens etc SERIAL NUMBER 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 Serial Number INSTALLATION APPLICATIONS This amplifier is designed for operation in vehicles with 12 volt negative ground electrical systems Use of this product in vehicles with positive ground and or voltages other than 12V may result in damage to the product and will void the warranty This product is not certified or approved for use in aircraft Do not attempt to bridge the outputs of this amplifier with the outputs of a second amplifier including an identical one Chassis Ground PLANNING YOUR INSTALLATION It is important that you take the time to read this manual and that you plan out your installation carefully The following are some considerations that you must take into account when planning your installation Cooling Efficiency Considerations The outer shell of your JL Audio amplifier is designed to remove he
17. ill result in lower sensitivity quieter for a given input voltage Amplifier Controls Fiter Freq FN WF 65 Input Sens LPFilter 55 a 0 Off 1248 24dB 40 200 To properly set the amplifier for maximum clean output please refer to Appendix A page 12 in this manual After using this procedure you can then adjust any or all Input Sens levels downward if this is required to achieve the desired system balance Do not increase any Input Sens setting for any channel s of any amplifier in the system beyond the maximum level established during the procedure outlined in Appendix A page 12 Doing so will result in audible distortion and possible speaker damage Filter Controls Most speakers are not designed to reproduce the full range of frequencies audible by the human ear For this reason most speaker systems are comprised of multiple speakers each dedicated to reproducing a specific frequency range Filters are used to select which frequency range is sent to each section of a speaker system The division of frequency ranges to different speakers can be done with passive filters coils and or capacitors between the amplifier outputs and the speakers which are acceptable and commonly used for filtering between mid range speakers and tweeters Filtering between subwoofer systems and satellite speaker systems is best done with active filters which cut off frequency content at the inp
18. in materials and workmanship for a period of ninety 90 days from the original date of purchase The warranty term is extended to two 2 years if installation is performed or approved by an authorized JL AUDIO dealer proof of installation or approval required on purchase receipt This warranty is not transferrable and applies only to the original purchaser from an authorized JL AUDIO dealer Should service be necessary under this warranty for any reason due to manufacturing defect or malfunction JL AUDIO will at its discretion repair or replace the defective product with new or remanufactured product at no charge Damage caused by the following is not covered under warranty accident misuse abuse product modification or neglect failure to follow installation instructions unauthorized repair attempts misrepresentations by the seller This warranty does not cover incidental or consequential damages and does not cover the cost of removing or reinstalling the unit s Cosmetic damage due to accident or normal wear and tear is not covered under warranty Warranty is void if the product s serial number has been removed or defaced Any applicable implied warranties are limited in duration to the period of the express warranty as provided herein beginning with the date of the original purchase at retail and no warranties whether express or implied shall apply to this product thereafter Some states do not allow limitations on implied warranties t
19. lifier input signals are always summed to mono Buffered pre out signals remain in stereo off On Remote Bass Port JL AUDIO A1800 IMPORTANT Mounting the amplifier upside down is strongly discouraged If mounting the amplifier under a seat make sure there is at least 1 inch 2 5 cm of space above the amplifier s outer shell to permit proper cooling Safety Considerations Your amplifier needs to be installed in a dry well ventilated environment and in a manner which does not interfere with your vehicle s safety equipment air bags seat belt systems ABS brake systems etc You should also take the time to securely mount the amplifier using the supplied screws so that it does not come loose in the event of a collision or a sudden jolt to the vehicle Stupid Mistakes to Avoid Check before drilling any holes in your vehicle to make sure that you will not be drilling through a gas tank brake line wiring harness or other vital vehicle system e Do not run system wiring outside or underneath the vehicle This is an extremely dangerous practice which can result in severe damage to your vehicle and person Protect all system wires from sharp metal edges and wear by carefully routing them tying them down and using grommets and loom where appropriate Do not mount the amplifier in the engine compartment under the vehicle on the roof or in any other area that will
20. n the following countries Austria Belgium Brazil Canada China France Germany Indonesia Italy Japan Republic of Korea Mexico Netherlands Norway Russian Federation Singapore Sweden Switzerland United Kingdom and all other PCT countries A1800MAN 04 2006
21. nnecting two speakers each to one set of positive and negative terminals will result in a parallel speaker connection If only connecting one pair of speaker wires it is not necessary to use both sets of connections JL AUDIO A1800 AMPLIFIER STATUS INDICATOR LIGHTS amp PROTECTION CIRCUITRY There are two status indicator lights on the input control end of the amplifier Amplifier Status O oO Power Protect Amplifier input signals are always summed to mono Buffered pre out signals remain in stereo 1 Power Green lights to indicate that the amplifier is turned on and operating normally 2 Protect Red Indicates that the amplifier protection circuitry has been activated to prevent product failure due to a short circuit or a dangerously low impedance connected to the amplifier output s Connecting the speaker outputs to an impedance lower than 2 ohms will cause this protection mode to activate When this protection mode is activated the amplifier will reduce it maximum power output to protect its circuitry which will manifest itself as increased distortion When the problem is corrected the amplifier will return to normal operation Advanced Rollback Thermal protection Unlike conventional thermal protection systems which shut down an amplifier when it overheats this system protects the amplifier by gradually reducing power output if the amplifier s safe operating temperature is exceede
22. t the Input Sens rotary control will operate within that voltage window If you are using an aftermarket source unit or an OEM interface processor with conventional preamp level outputs this is most likely the position that you will use The High position on the Input Voltage switch selects an input sensitivity range between 800mV and 8V This is useful for certain high output preamp level signals as well as speaker level output from source units and small amplifiers To use speaker level sources splice the speaker output wires of the source unit or small amplifier onto a pair of RCA plugs No line output converter is needed in most cases IMPORTANT The output of the amplifier will decrease for a given input voltage when the Input Range switch is placed in the High position Conversely the output will be higher with the switch in the Low position While this may sound counter intuitive it is consistent with the descriptions above JL AUDIO A1800 AMPLIFIER CONTROLS 1 Input Sens Once the appropriate Input Voltage range has been selected the control labeled Input Sens located in the Amplifier Controls section can be used to match the source unit s output voltage to the input stage of the amplifier for maximum clean output Rotating the control clockwise will result in higher sensitivity louder for a given input voltage Rotating the control counter clockwise w
23. talling amplifier systems with main fuse ratings above 60A FUSE REQUIREMENTS It is absolutely vital that the main power wire s to the amplifier s in the system be fused within 18 inches 45 cm of the positive battery post connection The fuse value at each power wire should be high enough for all of the equipment being run from that power wire If only the A1800 is being run from that power wire we recommend a 80A fuse be used ANL big blade fuse AGU big glass fuse or MaxiFuse big plastic body fuse types are recommended No fuse is required or recommended directly before the amplifier power connection If one is desired we recommend the use of a 80A AGU AFS or MaxiFuse type JL AUDIO A1800 TURN ON LEAD The A1800 uses a conventional 12V remote turn on lead typically controlled by the source unit s remote turn on output The amplifier will turn on when 12V is present at its Remote input and turn off when 12V is switched off If a source unit does not have a dedicated remote turn on output the amplifier s turn on lead can be connected to 12V via a switch that derives power from an ignition switched circuit The A1800 s Remote turn on connector is designed to accept 18 AWG 12 AWG wire To connect the remote turn on wire to the amplifier first back out the set screw on the top of the terminal block using the supplied 2 5 mm hex wrench Strip 1 2 inch 12mm of wire and insert the bare wire into
24. the terminal block seating it firmly so that no bare wire is exposed While holding the wire in the terminal tighten the set screw firmly taking care not to strip the head of the screw and making sure that the wire is firmly gripped by the set screw INPUT SECTION The A1800 s input section allows you to send signal to the amplifier section through the use of two differential balanced inputs one for the left channel signal and one for the right channel signal Connection is via RCA type jacks OTe Inputs CH1 Left input Voltage L Low High You may run a stereo or a mono signal into the inputs of the amplifier The amplifier s input section automatically sums stereo signals to mono for the internal amplifier section The amplifier will operate with only one input connection left or right but will require an increase in input sensitivity to overcome the loss of signal Ifa mono input signal is to be run we recommend that you use a Y adaptor to split the mono signal into both inputs of the amplifier INPUT VOLTAGE RANGE A wide range of signal input voltages can be accommodated by the A1800 s input section 200mV 8V This wide range is split up into two sub ranges accessible via a switch located to the left of the Input Connectors The Low position on the Input Voltage switch selects an input sensitivity range between 200mV and 2V This means tha
25. to these preamp outputs should have its input voltage switch set to the Low position EH IMPORTANT If you plan to use the Pre Outs to feed a stereo amplifier you must connect a stereo signal to the input of the amplifier A mono signal into the amplifier will result in a mono signal out of the preamp output SPEAKER OUTPUTS The A1800 s speaker outputs are designed to accept 16 AWG 8 AWG wire The A1800 is designed to deliver power into speaker loads equal to or greater than 2 ohms To connect the speaker wires to the amplifier first back out the set screws own the top of the terminal block using the supplied 2 5 mm hex wrench Strip 1 2 inch 12 mm of insulation from the end of each wire and insert the bare wire into the terminal block seating it firmly so that no bare wire is exposed While holding the wire in place tighten the set screw firmly taking care not to strip the head of the screw Speaker Output Mono min 2 0 o o 0o IMPORTANT Speaker loads below 2 ohms nominal are not recommended and may cause the amplifier to initiate a protection mode which reduces power output o You will notice that there are two positive lt connections and two negative connections This is to facilitate multiple speaker wiring The two positive and two negative connections are connected in parallel inside the amplifier Co
26. ut to the amplifier Active filters are more stable than passive filters and do not introduce extraneous resistance which can degrade subwoofer performance The active filter built into the A1800 can be used to eliminate potentially harmful and or undesired frequencies from making their way through the amplifier sections to the speaker s This serves to improve tonal balance and to avoid distortion and possible speaker failure Correct use of these filters can substantially increase the longevity and fidelity of your audio system The A1800 employs a sophisticated variable low pass active filter for its internal channel This feature is designed to attenuate frequencies above its filter frequency so that the system s subwoofers do not reproduce any audible midrange content 2 Filter Operation The low pass filter in the A1800 is fully variable between 40 Hz and 200 Hz via the Filter Freq control knob and features the ability to select between a moderate 12dB per octave or a steep 24dB per octave slope via the Mode Slope switch Depending on the subwoofer system and the vehicle different slopes may be required to produce a smooth transition to the mid bass speakers in the system Experiment to find the slope which best matches the acoustic requirements of your system JL AUDIO A1800 Tuning Hint A trunk mounted sub whose output has to fight through a rear deck or a back seat often benefits
27. within 18 inches 45 cm wire length of the positive battery post This fuse is essential to protect the vehicle Do not install the fuse until the power wire has been securely connected to the amplifier 4 Run signal cables and remote turn on wire from the source unit to the final amplifier mounting location 5 Run speaker cables from the speaker systems to the amplifier mounting location 6 Find a good solid metal grounding point close to the amplifier and connect the negative power wire to it using appropriate hardware use of the JL Audio ECS master ground lug XA MGL 1 is recommended Use the same size power wire as the wire connected to the 12VDC connection 4 AWG no longer than 36 inches 90 cm from the amplifier to the ground connection point In some vehicles it may be necessary to upgrade the battery ground wire See page 5 for important notice 7 Securely mount the amplifier using the supplied screws 8 Connect the positive and negative power wires to the amplifier A fuse near the amplifier is not necessary 9 Connect the remote turn on wire to the amplifier 10 Connect the input cables to the amplifier 11 Connect the speaker cables to the amplifier 12 Carefully review the amplifier s control settings to make sure that they are set according to the needs of the system 13 Install the power wire fuse 80A for a single A1800 and reconnect the negative battery post terminal 14 Turn on th
28. x A page 12 to set the input sensitivity for maximum low distortion output My amplifier doesn t turn on Check the fuse not just visually but with a continuity meter It is possible for a fuse to have poor internal connections that cannot be found by visual inspection It is best to take the fuse out of the holder for testing If no problem is found with the fuse inspect the fuse holder Check the integrity of the connections made to each of the 12VDC Ground and Remote terminals Ensure that no wire insulation is pinched by the terminal set screw and that each connection is tight Check to make sure there is 12V at the Remote connection of the amplifier In some cases the turn on lead from the source unit is insufficient to turn on multiple devices and the use of a relay is required To test for this problem jump the 12VDC wire to the Remote terminal to see if the amplifier turns on If this does not work proceed to the next step get a distorted attenuated sound coming out of the speaker s Check the speaker wires for a possible short either between the positive and negative leads or between either speaker lead and the vehicle s chassis ground If a short is present you will experience distorted and or attenuated output The Protect light will illuminate in this situation It may be helpful to disconnect the speaker wires from the amplifier and use a different set o
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