JBL Basspro SL2 Subwoofer Guide [Should You Buy?]

This article looks at one of the top JBL subwoofers on the market today. The JBL Basspro SL2 subwoofer is a great choice for enhancing your home theater experience.

In our look at the best JBL subwoofer for your home, the JBL Basspro SL2 was named the best under-seat subwoofer. Ideal for use in cars, it also works really well in your home theatre setup. If you’re after something that can be hidden away nicely and will still provide epic sound – the JBL Basspro SL2 subwoofer is perfect for you.

If you’re not sure if this subwoofer is for you, check out our guide below to help give you a better understanding.

Let’s get into it and find out a little more about the JBL Basspro SL2 subwoofer.

JBL Basspro SL2 Subwoofer

JBL Basspro SL2 Subwoofer Guide

JBL Basspro SL2 – Powered Under Seat Subwoofer System

JBL Basspro SL2 Subwoofer
Image source: JBL

JBL Basspro SL2 is a standalone powered subwoofer system for cars. It’s a compact sub that mounts under the seat, making it easier to install in any vehicle to add that extra bass to the sound system. 

It’s a 125 W subwoofer with a flat, rectangular housing. All the ports are on the front for easy access, while the grille is on the top. You can connect it to the head unit in your car through a sub-output. You can even install two of these, one under each seat on the front, to create a powerful bass output. 


The shallow profile design of this JBL car subwoofer is its highlight, as it conveniently sits under the seat without requiring too much effort for installation. You basically just need to connect it with the head unit. 

While it may be for under-seat installation, you can install it on the rear as well, should you have space for it. 

This 8-inch subwoofer produces sound from 0 dB to 9 dB at 70 Hz. But it also features high-pass filters and limiters that improve the quality of the bass. With bass speakers in cars, it’s easier to get higher bass at the expense of quality, but that’s hardly the case with this sub. 

It uses a class D amplifier that doesn’t overheat or fail even when used for hours. More importantly, unlike amps in normal subwoofers, this one doesn’t take a toll on the vehicle’s electric system. In other words, it’s power-efficient and runs on low-power input. 

The sub also provides crossover control, where you can adjust the upper and mid-bass according to your preferences. It tunes the crossover in a way that it’s subtle and almost unnoticeable. 

The Bass Boost feature of the speaker minimizes the peaks and dips according to the acoustics of the vehicle. Similarly, it can also adjust the volume of the bass corresponding to the main unit in your car. 

For the convenience of access and control, it’s compatible with JBL GTO-RBC, which is a remote volume control that lets you adjust the bass remotely. However, that’s a standalone product and does not come with this subwoofer. 


  • Compact, durable housing
  • High-quality bass 
  • Easy equalization
  • Low power input


  • Takes time to set up that ideal distortion-free bass
  • Not ideal for large vehicles (RVs, campers, etc.)

If you’re interested in learning more about JBL subwoofers, check out our review of the best JBL subwoofer. Alternatively, see our favorite wireless subwoofer from Sony.