Our editorial staff evaluates products and services independently, but Top Ten Reviews may earn money when you click on links. Learn More


JBL GTO Series Review

Author by

PROS / It has the highest continuous power-handling rating of the car speakers in our lineup.

CONS / Peak power handling is below average.

 VERDICT / With exceptional audio quality and one of the loudest speakers in our tests, the JBL GTO series is one of the best car speaker series available.

In the audiophile world of hi-fidelity speakers, you can find JBL speakers almost everywhere: your local rock venue's PA system, your uncle's fancy home theater, your best friend's over-ear headphones, your coworker's Bluetooth speakers. It only makes sense that you'd also find JBL speakers in cars as well. With some of the most accurate frequency responses and one of the most efficient speakers in our loudness comparison tests, JBL's GTO series of car speakers are durable, loud and capable of providing a great audio experience. For these reasons, it earns the Top Ten Reviews Silver Award for best car speaker.

JBL GTO Series Visit Site

The GTO series has speakers for every installation size, from 3.5-inches to 6 x 9-inches. Each speaker is made with a carbon-injected woofer on a fiberglass-reinforced poly frame. For the purpose of this review, we tested and evaluated the best 6 x 9-inch speaker in the series – GTO939. After testing several different sizes, we decided that the 6 x 9-inch speaker of each car speaker series was the best reflection of the quality of the series as a whole. Still, it's important you measure the speaker installations on your car before purchasing replacements.

  1. The lowest frequency that the speaker can produce, according to the manufacturer.
    Lower is Better.
  2. 2 JBL GTO
    46 Hertz
  3. 28 Hertz
  4. 28 Hertz
  5. Category Average
    43.80 Hertz

Audio Performance

We determined audio quality with two tests: a frequency accuracy test and a subjective ear test. In the former, we recorded the speaker as it played a tone that smoothly transitioned from 20Hz to 20kHz. Then we analyzed the frequency signature and graded the low, mid and high frequencies. From this test, the GTO939 was given an A- at every frequency range. So while it wasn't the most accurate car speaker in our tests, it was one of the top car speakers in each range.

In the subjective ear tests, we had listeners rate the speaker as they listened to it play a variety of songs. In this test, it tied the highest overall audio rating. In addition, online user reviews show that it's also among the most popular speakers available. If you place a premium on high-quality audio, the JBL GTO speakers are one of your best options.

Power Handling

To gauge each car speaker's efficiency, we measured the decibels produced by each car speaker at 1 meter while using an equal volume setting on the amplifier. In this way, we could see which speakers were the most efficient at converting electricity to volume. In the test, the JBL GTO939 received a very loud rating, which means that it was just 1 dB below the loudest speaker. Unless you have a trained ear, you won't be able to discern the difference between it and the loudest speaker. However, the power required to increase the volume by 1 dB is about 33 percent.

The sensitivity rating, reported by the manufacturer, is 94 dB at 1 meter using a 2.83-volt current. This means it has one of the highest sensitivity ratings in our review, which is reflected by the excellent results with the comparative loudness tests. However, the best power-handling feature is the 200 RMS watt continuous power handling. This is the highest continuous power-handling specification in our review by 50 watts. When you combine this with the highly efficient speakers, you have car speakers that you can really turn up without fear of clipping the tweeters and damaging the woofers.

The one minor downside is the below-average peak power handling of 300 watts. Generally, you want the peak power handling to be at least twice as high as the continuous power handling so you have enough room for spikes in the music to occur without damaging the speaker.

The JBL GTO car speakers are one of the few speakers in our car speaker review with a 3-ohm impedance. While impedance doesn't affect audio quality, it's important that you ensure your car's receiver or amplifier is rated for 3-ohm speakers. Otherwise, you risk burning out your amplifier or blowing the speaker.

Speaker Design Options

The JBL GTO series has speakers to fit every size you want. If you're an ambitious car audiophile, component speakers are available, which allow you to better customize and tune your car audio to your preferences, because the woofers and tweeters are separate. Component speakers often require custom installations to place the tweeters in the perfect locations but are worth it if you want the absolute best audio for your car.

For those who just want a significant upgrade from their factory speakers, there are two-way and three-way speakers. These are woofers with either one or two tweeters built into the speaker. You can also adjust the angle of the tweeters so that the sound is aimed for the best acoustics in your car. Since each car is different, having adjustable tweeters is a great feature that most car speakers don't provide.

Help & Support

Each JBL GTO speaker comes with a one-year warranty. You can contact support by phone or email if you have any problems. JBL also offers a 30-day return policy, which is great for speakers because you can test them out to see how they sound in your car. There's also a helpful FAQs page for getting quick answers to common issues. The only missing support feature is a user forum where you can share concerns or ideas with other JBL users.


The JBL GTO series of car speakers are among the best car speakers available; it combines high quality audio with an efficiently loud output. The low, mid and high frequencies each received A- grades for accuracy, and it was tied as the most preferred audio quality in our subjective ear tests. While the continuous power-handling rating is higher than any speaker in our lineup, the peak power handling is below average. Regardless, these speakers are one of the best options for upgrading your car audio system.

JBL GTO Series Visit Site