Dual subwoofers are a great option for the enthusiast who can accommodate two subwoofers in the listening area. The benefits of dual subwoofers include increased dynamic headroom and a smoother bass response at more listening locations in the room.
Dual subwoofers are also harder to localize than a single subwoofer, which might be an important consideration for the enthusiast using very small speakers which require a high speaker/subwoofer crossover frequency.
Finally, two smaller subwoofers can often fit better into a room than a single larger subwoofer in terms of available floor space and visual impact, while offering similar or better performance as the single larger subwoofer.
For more information, refer to our tech article Why Go Dual?