It's not about more bass. It's about better bass.
A good sound system requires an optimized bass response. It doesn't matter how advanced or expensive the speakers are: Bass that sounds boomy or bloated can ruin the listening experience by drowning out higher frequencies or muddying the low end.
But tight, well-defined, evenly distributed bass can enhance the listening experience - be it for a home theater or a stereo system.
For sound systems that are meant to cover a relatively large area, multiple subwoofers can help maintain clarity while delivering all the punch you could ask for.
Subwoofer placement and listening positions
Bass quality is largely determined by two factors: subwoofer placement and listener position. In a typical home listening environment, bass can sound overdriven in some places and thin in others. It depends on where the subwoofer is placed and where you are in relation to it.
Room resonance refers to areas in a room where some of the subwoofer's sound waves build up, making the bass louder than it should be. Room resonances can also create areas where sound waves cancel each other out, making the bass weak.
You can avoid or minimize these resonant peaks and dips by experimenting with subwoofer placement.
More can actually be better
There's another factor that can affect your system's low-end response, and that's the number of subwoofers you use.
While you can usually handle enough bass for an average-sized room, additional subwoofers can reduce room resonance and improve the overall bass quality throughout the room.
The thing to understand is that it's not about adding more bass; it's about distributing it evenly throughout the room.
Two (or even four) properly placed subwoofers can effectively cancel some, if not all, room resonances. This will improve overall bass performance and will expand the field of ideal listening spaces in the room.
Think of multiple subwoofers as a heater that can affect all areas of the room, whereas a single subwoofer is like a floor fan with limited range.
A typical setup uses two subwoofers placed in opposite corners of the room. This is a sensible way to cover a room with an even but energetic low-end response.
Stereo Hub can even handle wireless subwoofer systems that include four subwoofers (two Solo and two Duo). While four subwoofers may seem like overkill, having a pair is manageable and will provide better bass than a single subwoofer alone.
The improvement in bass response with multiple subwoofers is so obvious that many advocate buying several smaller subwoofers instead of one large one. The performance of four generally beats two, and two is always better than one.
Where to place two subwoofers
If you are using two subwoofers, experiment with the placement as follows: