Although the Kia EV6 ranks among the best electric cars you could buy in 2024, according to Consumer Reports, owners have been questioning the audio quality of the Meridian sound system for a while. One such thread concerning Kia EV6 sound quality on the r/KiaEV6 subreddit dates back to 2022. More recent issues center around the Meridian system’s bass output levels.
For 2025, Kia offers the 14-speaker Meridian Premium Audio System in its top-trim GT-Line rear-wheel and all-wheel-drive models. Meridian says it uses its proprietary DSP (digital signal processing) technologies to “deliver a state-of-the-art listening experience” to Kia owners and passengers. Meridian goes on to say:
“Loudspeakers are strategically positioned and seamlessly integrated into the luxury automotive interior, allowing each passenger to enjoy an audio experience of unparalleled quality, no matter where they are in the vehicle.”
However, somewhere between design and execution, some wires got crossed, resulting in an out-of-phase rear subwoofer. Rather than pointing fingers to assign blame for the problem, some Kia EV6 owners are taking matters into their own hands, performing a simple rewiring in just a matter of minutes.
What is this simple rewiring task?
The EV6’s subwoofer is hooked up, just not correctly, causing its sound to be out-of-phase with the rest of the sound system, similar to the way Active Noise Cancellation makes your car interior quieter. The Drive says:
“It’s not that the subwoofer in the factory Meridian setup is making no bass; it’s just being canceled out by equal and opposite frequencies from other speakers inside the car. Unplug every other sound device and you’ll hear the trunk-mounted sub thud. Plug them back in, though, and they counteract the output from the device.”
Accessing the Meridian subwoofer wire-harness in the back of a Kia EV6 requires removing some of the trim pieces in the trunk. The first piece in the trunk’s floor is removable without tools whereas the piece closer to the rear hatch has two threaded fasteners that may be tight enough to require a large flat screwdriver. Once the wire harness is exposed you’ll see a connector with an orange tab on it.
The rewiring process involves removing that orange tab, unpinning the red and black wire pairs on the right side of the connector, and reversing the wires in each pair. So, instead of the stock red-black-red-black order from top to bottom, it’ll be black-red-black-red when completed. Technically Jeff posted a detailed video of the process on their YouTube channel but credits Reddit user nex703’s “Meridian Sound Subwoofer fix” post on the r/KiaEV6 for the inspiration.
