JBL GTO939 Review

I had installed a pair of aftermarket speakers in my vehicle quite some time ago, and they had finally given up, and were wore out. I had been very happy with my previous speakers so I was looking for something similar, or better but within a strict budget. A friend told me about the JBL GTO939 speakers that he had recently installed in his vehicle. He said that they were within my budget, but had the specifications of much higher priced speakers. He was very positive about them, and I wanted to find out more. I found out that they are very reasonable in terms of price, and perform as well as speakers two to three times their price point. They have so many positive reviews all across the board on every aspect and feature. I ordered them, and couldn’t wait to install them and try them for myself.

Who are these speakers designed for?

The JBL GTO939 speakers are designed with people in mind who:

  • Want great sound quality
  • Want easy installation
  • Have 6” x 9” speakers
  • Want to replace old and worn out speakers
  • Want an aftermarket speaker upgrade
  • Want a full range speaker
  • Has a budget, but still wants a great sound quality

JBL are an audio company known for producing good quality speakers. The JBL GTO939 are full range speakers that have been developed for crisp, clear sound. JBL GTO939 speakers are 3 way speakers, and have a few appealing features.


One of the biggest appeals of the JBL GTO939 speakers is how easy they are to install. While some speakers require specialist installation and modification to the vehicle, these do not. They were designed to replace stock OEM 6×9 speakers on almost any make and model of vehicle, and as an upgrade for any aftermarket speaker so you can install them yourself at home. You don’t need any special tools for installation, but if you’re trying to replace a smaller speaker with these, then you will need to modify the space to allow the speaker to fit.

Plus One Cone Technology

The JBL GTO939 speakers have JBL’s own Plus One cone technology. This is a cone that JBL have designed from specialist materials to be larger than average cones. A speaker produces sound by vibrating air, so the larger the cone, the more air it can vibrate. In these speakers, the Plus One cone helps it to produce better bass quality.


The JBL GTO939 speakers have peak power handling of 300W per speaker, 600W for the pair. They have RMS power handling of 100W, 200W per pair. The wattage in these speakers mean that you can use them with your stock vehicle audio system and you will notice an improved sound quality. If you upgrade your vehicle audio system to run them through an amplifier then they really come into their own, and produce an incredible sound quality.


The sensitivity rating is more important than most people realize. The sensitivity rating shows how the speaker will respond to power, so the higher the rating, the better the response. The power needed to deliver the same volume decreases by around half with each 3dB increase. The JBL GTO939 speakers have a sensitivity rating of 94dB. This means that if you have set your volume and you’re sing these speakers, you would use around 50 watts of power. In 91dB speakers you would need to use around 100 watts for the exact same volume level.


The tweeters in the JBL GTO939 is one of the speakers huge advantages over other speakers in the same price range. Actually, they’re one of the components of these speakers that allow them to compete with speakers in a higher price bracket. The one inch tweeters are made from a My/Ti, which is a Mylar and Titanium composite. They are designed to give more power handling, reduce distortion, and be more efficient. The distortion reduction is more evident in the mid range frequencies, which is where most tracks have the vocals. This allows the JBL GTO939 to give you a much crisper, clearer sound than other speakers.


The also have UniPivot. UniPivot is the system JBL designed that allows you to adjust the position of the tweeter so it is towards you. There is after installation customization as there’s also a control switch so you can adjust the tweeter dB output to your own preferences

Click Here To See Specifications, Customer Reviews & Rating

What I Like

  • These speakers have a minimum mounting depth of 2” which means that they are compatible with a very wide range of vehicles
  • They have a frequency response of 45 – 21,000 Hz
  • They produce a well balanced sound
  • They are a reasonably speaker, with the quality of a much higher priced speaker
  • These speakers have gone through a wide range of testing to ensure durability and high quality materials

What I Don’t Like

  • They have no hardware in the box, so may require some additional purchases
  • They work with the stock audio system, but most of their advantages are massively improved by upgrading your audio system
  • There is room for some improvement in the upper mid range, and deeper lows.

Frequently Asked Questions

Will these speakers fit in my vehicle?

The JBL GTO939 speakers are compatible with a huge range of vehicles. As a general rule, if your vehicle has 6” x 9” speakers, then these ones can replace them. They have a minimum mounting depth of 2” which is quite shallow, and can mean that they can be installed into almost any vehicle without any additional modification.

What comes in the box?

The box includes two 2 way 6 x 9 speakers, 2 bottom mount rings, 2 grilles and grille badges, eight machine screws, eight self tapping screws, eight split lock washers, eight flat washers, eight hex nuts, eight sped clips, warranty and instructions for installations. Everything you could need to install your speakers is in the box

Are they individual or a pair of speakers?

They are sold as a set of two speakers.

What comes in the box?

The box contains two JBL GTO939 3 way speakers.

Is there any hardware?

No, you will need to find the hardware and connectors yourself. Though this does mean that you can make sure that all the connectors are the right size for your vehicle.

Do they have a warranty?

Yes, they come with a one year warranty.

See More Questions and Answers

Read Also: Kenwood KFC-6965S Review


The JBL GTO939 3 way speakers are capable of power, performance and quality. They are reasonably priced but with the specifications that you might expect from more expensive speakers. They are easy to install, but don’t come with any additional mounting hardware. This is easily solved by a trip to the hardware store, and it does mean that you can make sure that you have the proper sized connectors for your vehicle. Overall, they are a great speaker that give a much better sound quality than the factory speakers in your car can. Still if you are looking for other speakers you may read New Kicker DS693 Review.

Leave a Reply