Jensen JA1B, JA2B, JA4B - Power Amplifer Manual
- 1 Preparation
- 2 Connection Descriptions
- 3 Audio Inputs and Controls
- 4 Power and Speaker Connections
- 5 Typical Wire Routing
- 6 Device Connections
- 7 Controller App Download/Installation
- 8 Bluetooth Pairing with App and AMP
- 9 JENSEN DSP AMP App Operation
- 10 Specifications
- 11 Troubleshooting
- 12 One-Year or Three-Year Limited Warranty
- 13 References
- 14 Download manual
- 15 In Other Languages
Preparation
Please read entire manual before installation. Due to the technical nature of amplifiers, it is highly recommended that your amplifier is installed by a professional installer or an authorised dealer.
Before You Start
- Disconnect negative battery terminal. (consult a qualified technician for instructions)
- Avoid installing the amplifier where it would be subject to high temperatures, such as from direct sunlight. or where it would be subject to dust. dirt or excessive vibration.
- Use extreme caution when drilling holes to avoid damaging fuel lines or existing vehicle wiring.
- All amplifier installations require power, signal and speaker wires (not included).
- An amplifier installation kit (sold separately) is highly recommended to facilitate the installation. Consult your dealer for recommendations.
Mounting Location
- Choose a mounting location for the amplifier. Suggested locations include under a seat or in the trunk.
- The amplifier can be mounted horizontal (recommended) or vertical. For optimum performance, make sure to provide at least 1" of space around all sides. Do not mount the amplifier under carpets or where airflow is restricted.
- Do not install the amplifier where it may be exposed to moisture.
- The optimum mounting location varies between vehicles. Remember to test all amplifier functions before completing the final mounting procedure.
Connection Descriptions
NOTE:
Be sure to follow specific instructions included with your amplifier installation kit (not included with this amplifier). The information below should be used as a general guideline only.
Power Wire (+ 12V)
- Disconnect negative battery terminal before proceeding. Consult a qualified technician for instructions if you are unsure.
- Plan wire routing before cutting any wires to length. Begin by routing the power + 12V wire from the battery to the amplifier location. Use a grommet when running wires through the firewall or metal openings. Avoid running the power wire near existing vehicle wiring to prevent induced noise from entering the audio system.
- Use extreme caution when drilling holes to avoid damaging fuel lines or existing vehicle wiring.
- The + 12V wire MUST be fused within 18" of the battery for protection of the vehicle's electrical system.
Ground Wire (GND)
- The amplifier ground wire should be as short as possible (no more than 36" or 1 metre). Choose a clean unpainted section of metal or the vehicle chassis when attaching the ground connection. Be sure to clean the area of any dirt or grease.
Remote Turn-on Wire (REM)
- The remote turn-on wire connects to the head unit's amplifier turn-on lead or power antenna output.
Speaker Wires
- Choose adequate gauge speaker wire depending on your exact amplifier/speaker combination. Be sure to observe polarity when connecting.
- Do not ground any speaker wires or connect any speaker wires together.
Input Signal
- The amplifier's input signal connects to the head unit's low level (RCA) or high level (speaker wire) outputs.
- Low level input signals deliver the best performance. If unavailable. use the high level inputs - when interfacing with factory head unit for instance.
Power/Protect Indicators
- Colored LED indicators illuminate from the plastic power terminal.
- The blue LED illuminates during normal operation(POWER) and the red LED indicator is visible when the amplifier detects a fault (PROTECT).
- Do not use both low and high level inputs at the same time. Connect only one or the other.
- Keep low level inputs away from any power wires to avoid engine noise.
- Never run any wires underneath or outside the vehicle.
Audio Inputs and Controls
- Line Output
- Line Input
- High Level Input
- Reset
- Do not place anything in this area that could block the radio waves. as this may be a problem with your Bluetooth connection.
Power and Speaker Connections
- Power/Protect LED
- Ground Connection
- Remote Tum On
- + 12V DC Battery Connection
- Fuse(s)
- Speaker Connections
Typical Wire Routing
JA1B
Speakers, subwoofer, head unit, wiring kit, and speaker wire sold separately.
JA2B
Speakers, subwoofer head unit, wiring kit, and speaker wire sold separately.
JA4B
Speakers, head unit wiring kit and speaker wire sold separately.
Device Connections
Speaker Connections
Connect speaker wires observing polarity. The minimum impedance load for the amplifiers is 2 ohms stereo and 4 ohms bridged. Use of loads lower than these is not recommended and may cause amplifier damage. The amplifiers can be wired for stereo, bridged or stereo/bridged simultaneous operation.
Typical speaker connections shown above
Input Signal Connections
Low Level Input (RCA)
Low level (RCA) input signal is preferred for best performance. Typical trunk-mount amplifier installations require a 17-20 foot RCA cable. Most trucks and under-seat applications require a 6-9 foot RCA cable. Using twisted pair construction RCA cables will minimise noise.
High Level Input
(Speaker Wire)
High level inputs should only be used when RCA outputs are not available from the head unit. Connect the head unit speaker outputs to the high level input connector as shown below. The black wire (signal reference ground) may or may not require a connection to chassis ground - depending on your particular installation.
Note: Do not use both low and high level inputs at the same time - connect only one or the other.
Controller App Download/Installation
Scan the above QR Code to download the Jensen DSP Amplifier Controller app from the Apple App Store or Google Play Store onto your smartphone or tablet.
Use the app to control features including: X-Over. EQ, RGB Light Customisation. Volume and other amp settings directly from your smartphone or tablet via Bluetooth.
Note:
JA amp series do not support audio streaming and hands free calls via Bluetooth.
Bluetooth Pairing with App and AMP
- Touch the BT icon
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- Touch the Scan icon
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to search the Bluetooth amp. - Bluetooth amp list
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to show what amp is paired. (If only one amp is installed, one amp model number is displayed.) - Select the amp model number you want to install from the device list
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- Touch the drop down Icon
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to show the version number of App and amp and to see if the Bluetooth paring is completed successfully ![]()
- Touch Disconnect
![]()
to disconnect the amp from the App.
to search the Bluetooth amp. 
to show what amp is paired. (If only one amp is installed, one amp model number is displayed.) 
to show the version number of App and amp and to see if the Bluetooth paring is completed successfully 
to disconnect the amp from the App.JENSEN DSP AMP App Operation
| Input level Control (Master Level at HOME Mode) | The input level control (gain) is used to obtain the best possible match between the head unit audio output and the amplifier input. Begin by turning the input level control fully counterclockwise. Next. tum up the head unit volume control around 3/4 of the way up. Adjust the input level control clockwise until audible distortion is heard, then slightly counterclockwise to provide the best match. Repeat for all input level controls. |
| X-OVERMode (JA2B and JA4B) | The crossover is used to filter out frequencies above or below a certain point. Choose LPF when using the amplifier with subwoofers. HPF when using with midrange/tweeter combinations and FULL when using with coaxial-type speakers. Note: Choose FULL when using the amplifier in stereo/ bridged simultaneous mode. In this mode. passive crossovers are required. Failure to use the correct passive components may damage the amplifier and/ or speakers. Consult a qualified professional for recommendations. |
| X-OVER Mode (JA1B) | JA 1 B (Mono) amp works only with LPF. |
| X-OVER Control | This control allows precise adjustment of the crossover frequency. |
| Bass Boost | This control provides additional boost@ 45Hz when used with subwoofers. Adjust this control with caution - as improper use can damage speakers! |
| EQ Presets | Select between the following EQ presets: Classic, Pop. Rock. Jazz. Custom (allows user to enter custom EQ settings). |
| Custom EQ | Custom EQ from EQ Presets is selected to make the customised audio settings and each gain per frequency can be adjusted at EQ Mode of the App. |
| RGB Color | It allows the amp illumination to be turned off or on at RGB mode of the App. One color or multiple colours can be controlled. |
Specifications
| JA1B | |
| Continuous | 290W RMS x 1 Channel at 40 |
| Power Output: | 470W RMS x 1 Channel at 20 595W RMS x 1 Channel a 10 (50Hz and 1% THD+N) |
| Dynamic Power: | 300W x 1 Channel at 50Hz at 4 0 545W x 1 Channel at 50Hz at 2 0 640W x 1 Channel at 50Hz at 10 (1% THD+N) |
| Maximum | 325W x 1 Channel at 50Hz at 40 |
| Dynamic Power: | 565W x 1 Channel at 50Hz at 20 690W x 1 Channel at 50Hz at 10 (10% THD+N) |
| Signal to Noise: | 68dBA reference 1 Watt RMS |
| THD+N: | <0.09% at 1 Watt RMS from 20Hz to 300Hz |
| Amplifier dimensions: | 2.16"x 9.56"x 5.59"(H x W x D) |
| JA2B | |
| Continuous | 95W RMS x 2 Channels at 40 |
| Power Output: | 105W RMS x 2 Channels at 20 225W RMS x 1 Channel at 40 BRIDGED (1% THD+N) |
| Dynamic Power: | 100W x 2 Channels at 1 kHz at 40 110W x 2 Channels at 1 kHz at 2 0 230W x 1 Channel at 1 kHz at 40 BRIDGED (1% THD+N) |
| Maximum | 140W x 2 Channels at 1 kHz at 40 |
| Dynamic Power: | 170W x 2 Channels at 1 kHz at 2 0 310W x 1 Channel at 1 kHz at 40 BRIDGED (10% THD+N) |
| Signal to Noise: | 72dBA reference 1 Watt RMS |
| THD+N: | <0.14% at 1 Watt RMS from 20Hz to 20kHz |
| Amplifier dimensions: | 2.16"x 6.57"x 5.59"(H x W x D) |
| JA4B | |
| Continuous | 90W RMS x 4 Channels at 40 |
| Power Output: | 115W RMS x 4 Channels at 20 230W RMS x 2 Channels at 40 BRIDGED (1% THD+N) |
| Dynamic Power: | 100W x 4 Channels at 1 kHz at 40 125W x 4 Channels at 1 kHz at 20 255W x 2 Channels at 1 kHz at 40 BRIDGED (1% THD+N) |
| Maximum | 125W x 4 Channels at 1 kHz at 40 |
| Dynamic Power: | 185W x 4 Channels at 1 kHz at 20 365W x 2 Channels at 1 kHz at 40 BRIDGED (10% THD+N) |
| Signal to Noise: | 70dBA reference 1 Watt RMS |
| THD+N: | <0.15% at 1 Watt RMS from 20Hz to 20kHz |
| Amplifier dimensions: | 2.16"x 8.38"x 5.59"(H x W x D) |
Troubleshooting
| Problem | Cause | Adion |
Unit will not tum on/no power LED indicator | + 12V wire not connected or incorrect voltage. REM wire not connected or incorrect voltage | Check connections for proper voltage (11-16VDC) |
| GND wire not connected | Check connection to ground | |
| Fuse(s) blown | Replace fuse(s) | |
Unit has power - LED is green but no sound | Speaker wires not connected | Check connections at speakers |
| Volume turned all the way down | Increase volume level at head unit | |
| One or more speaker wires touching each other or touching chassis ground | Insulate all bare speaker wires from each other and chassis ground | |
| Speaker(s) defective or damaged | Check/replace speaker(s) | |
| Input signal not connected | Check high or low level inputs for proper connection | |
Unit blows fuses | Incorrect fuse rating | Use fuse(s) with correct rating |
| + 12V wire touching chassis ground | Check for pinched wire | |
| Speaker(s) defective or damaged | Check/replace speaker(s) | |
Engine noise | Bad ground connection | Make sure amplifier is grounded to clean bare metal |
| Signal ground loop or RFI (radio frequency interference) | Re-route RCA cables from existing high current wiring | |
LED illuminates red (protect mode) | One or more speaker wires touching each other or touching chassis ground | Insulate all bare speaker wires from each other and chassis ground |
| Speaker(s) defective or damaged internally (shorted) | Check/replace speaker(s) | |
| Speaker load less than 2 ohms (stereo). Speaker load less than 4 ohms (bridged) | Adjust speaker load - amplifier will not operate al less than 4 ohms when bridged | |
Distorted audio output | Incorrect input signal type or input level too high | Check connections and reduce/adjust input level |
Low audio output | Incorrect input signal type or input level too low | Check connections and increase/adjust input level |
One-Year or Three-Year Limited Warranty
For more information and for the location of the nearest authorised service centre please contact us by one of the following methods:
- Call us toll-free at (888) 921-4088
(Monday-Friday, 9:00 a.m. to 5:00 p.m. EST) - E-mail us at cs@jensenmobile.com
References
Download manual
Here you can download full pdf version of manual, it may contain additional safety instructions, warranty information, FCC rules, etc.
Download Jensen JA1B, JA2B, JA4B - Power Amplifer Manual