Jensen amplifiers: DSP control from your phone
A review of the Jensen JA1B, JA2B, and JA4B car amplifiers with built-in DSP
In this article, we review three car amplifiers from Jensen: the JA1B, the JA2B, and the JA4B. All three amps offer built-in DSP (digital signal processing) that can be controlled through a smartphone app. Read on for more details.
Jensen’s been in the car audio game for a while, and now they’re back in the amp realm with three exciting new models. They all feature digital signal processing with app control, so they’ll not only power your speakers, but also give you in-depth command over your audio. Crutchfield Advisor River and I both played with the amps and Jensen's app and found them a great value-oriented solution to many listeners’ needs.
Amplifiers, with or without digitial signal processing, are essential to getting the most out of your speakers, especially if you're installing aftermarket speakers and/or a subwoofer. There are several signal processors which you can add separately to your system, but an amp with that capability built in makes dialing in the sound that much more convenient (and usually costs less overall).
If you're thinking about adding an amp to your vehicle, read our Car Amplifier Buying Guide for shopping tips. You can also peruse our Best Multi-channel Car Amps article for a look at some of our top sellers.
![Crutchfield Advisor River in back of car posing with Jensen DSP amps](http://images.crutchfieldonline.com/ImageBank/v20230306152600/ImageHandler/scale/978/978/core/learn/article/5005/Jensen-DSP-amps-River.jpg)
Affordable power for one, two, or more speakers
Crutchfield hasn't carried any Jensen amps for several years, so River and I were excited to check out what they were bringing to the plate. When I saw the price point for these amps, I immediately thought about how appealing they'd be to audio enthusiasts who might be curious about adding DSP to their system but might've been hesitant to go that route due to the cost.
All three Jensen JA amps use Class-D construction, which makes them highly efficient and capable of smooth output. River was impressed by their size: “They’re pretty compact, and could easily fit under a car seat or behind a glove box.” You can see her holding a JA2B above.
These amps can deliver a reasonable amount of power at four ohms. High-level and speaker-level inputs allow for simple connection to a variety of sources. They also all feature a variable bass boost at 45 Hz, allowing for more control over the low end.
While the amp aesthetics don’t scream “look at me,” the amps offer accessible connections and subtle LED logo badges to indicate when they’re on. The LED colors are customizable, which allows a touch of personality to shine through.
Now, let's take a quick look at the differences in them.
Compact Jensen amplifiers
![Jensen JA2B 2-channel DSP car amp on plain background](http://images.crutchfieldonline.com/ImageBank/v20230307134100/ImageHandler/scale/978/978/core/learn/article/5005/Jensen-DSP-amp-110ja2b.jpg)
JA2B 2-channel amplifier
The Jensen JA2B 2-channel amp delivers up to 95 watts RMS per channel at 4 ohms, and it is the smallest of the three amps, measuring at almost 6 inches square. It's also bridgeable so you can get up to 225 watts RMS out of it for your 4-ohm subwoofer.
Product Highlights
- 2-channel amplifier
- Power: 95 watts RMS x 2 at 4 ohms, 105 watts RMS x 2 at 2 ohms, 225 watts RMS x 1 bridged at 4 ohms
- Class D technology
- Preamp and speaker-level inputs
- Preamp outputs
- Size: 6-5/8"W x 2-1/4"H x 5-5/8"D
- 3-year warranty
![Jensen JA4B 4-channel DSP car amp on plain background and gold ball for scale (product page lists dimensions)](http://images.crutchfieldonline.com/ImageBank/v20230307143200/ImageHandler/scale/978/978/core/learn/article/5005/Jensen-DSP-amp-110ja4b.jpg)
JA4B 4-channel amplifier
The Jensen JA4B 4-channel amp delivers up to 90 watts RMS per channel at 4 ohms, and it also boasts an impressively small footprint, measuring at just under 9 inches by just under 6 inches. You can bridge it to power two subs, with up to 230 watts RMS to each at 4 ohms.
Product Highlights
- 4-channel amplifier
- Power: 90 watts RMS x 4 at 4 ohms, 115 watts RMS x 4 at 2 ohms, 230 watts RMS x 2 bridged at 4 ohms
- Class D technology
- Preamp and speaker-level inputs
- Size: 8-7/16"W x 2-1/4"H x 5-5/8"D
- 3-year warranty
![Jensen JA1B mono DSP car amp on plain background, close-up on power and speaker connections](http://images.crutchfieldonline.com/ImageBank/v20230307154300/ImageHandler/scale/978/978/core/learn/article/5005/Jensen-DSP-amp-110ja1b.jpg)
JA1B mono amplifier
The Jensen JA1B mono amp pounds out up to 595 watts RMS at 1 ohm (470 watts RMS at 2 ohms), so even without the DSP factor it's still a very attractive price on a cost-per-watt basis. This amp measures about an inch longer than the JA4B, so still quite small and able to be hidden away easily. Since it's stable down to 1 ohm, it'll work with a large number of sub and voice coil configurations.
Product Highlights
- Mono subwoofer amplifier
- Power: 290 watts RMS x 1 at 4 ohms, 470 watts RMS x 1 at 2 ohms, 595 watts RMS x 1 at 1 ohm
- Class D technology
- Preamp and speaker-level inputs
- Preamp outputs
- Size: 9-9/16"W x 2-1/4"H x 5-5/8"D
- 3-year warranty
![Audio and LED controls on the Jensen DSP AMP phone app](http://images.crutchfieldonline.com/ImageBank/v20230306164100/ImageHandler/scale/978/978/core/learn/article/5005/Jensen-DSP-amps-phone-app-screens.jpg)
Jensen DSP AMP app
Jensen’s DSP AMP app makes tweaking the amp settings simple. The first thing River and I did was link to a JA2B amp via a phone’s Bluetooth® connection, which was a snap. The app’s main screen presents a “Master Level” volume control, plus four EQ presets and a custom EQ. Tap “crossover,” and you get to a screen that provides a simple way to set the essentials like gain and crossover filters without having to fiddle with knobs on the amps. “The DSP app is straightforward; it took me about ten seconds to learn,” River said.
The crossover and EQ screens let you apply settings to up to two pairs of channels. You can apply low- and high- pass frequency filters, three slope options (6, 12, and 18 dB), plus bass boost. The RGB screen lets you choose the color of the amp’s illuminated badge, or set it to cycle through all its colors. "The LEDs are fun," said River, and I have to concur.
Highlights of the sound control app
- DSP adjustments on your phone or tablet via Bluetooth connection
- input level/gain, low-pass/high-pass filter, bass boost at 45 Hz
- EQ presets: Classic, Pop, Rock, Jazz, Custom (user defined)
- RGB color illumination control
- does not support audio streaming or hands-free calling
Listening test time
With the app going, it was time for a listening test. We fired up the 2-channel amp and immediately noticed how much clearer the mids and highs were, especially the vocals. Everything sounded simultaneously louder and cleaner. “I could hear a big difference in the music through the speakers,” noted River.
Then we had fun toying around with the app settings, trying to dial in certain tones for maximum impact, such as the bass and snare drum. Although the app only presents five frequency bands for changes, it doesn’t feel limiting in any way. For newbies to DSPs, it seems like a great intro. River confirmed: “These amps would be great for someone who wants control, but also simplicity. Even if you're not experienced with DSPs and EQs, you can still get an amp in there, add power, and get control."
A brief summary of these new Jensen amps
While we didn't get a chance to play with each amp individually, we can draw some conclusions from our time with the JA2B and the app. These amps are a great way to get into DSP without spending a ton of money. Their learning curves are not too steep, even for novice audio enthusiasts. Given that Jensen backs these amps with a 3-year warranty, they seem like a safe investment for giving your car's audio system a boost that'll also let you tweak your way to better sound.
Want to learn more about amps?
Don't forget to check out our Car Amplifier Buying Guide for more information about what to look for when you're in the market for a new amp. If you have any questions, contact our advisors via chat or phone.
Comments (1)
Please share your thoughts below.
Brandon from philadelphia
Posted on 10/7/2023
i have a dsp amp and i cant even use it my laptop wont download the app and i really dont care to own a cellphone. i got no one to call so in my case i have a 140 dollar paper weight cause thats all its good for without the app. byer beware these amps are 100% no good