Yes, it may be possible to adjust the subwoofer.

However, what you can adjust depends on what equipment is installed in the vehicle.
For example, if you have a device like a DSP that allows for fine-tuning, it becomes easier to adjust not only the subwoofer volume but also how it connects with the rest of the system.
On the other hand, depending on the system configuration, the range you can adjust may be limited.

Also, it’s usually easier to improve in-car listening comfort if you adjust while considering not just the subwoofer by itself, but also the balance with the front speakers and the overall sound.
It’s not only about adding bass—depending on the vehicle, you may need to reduce parts that feel too heavy, and fine-tune it so it transitions naturally.

If you can share the current system configuration, it will be easier to let you know how far the adjustments can go.
Even if you don’t know, we can sort it out while checking the actual vehicle, so please feel free to contact us first.