Why Go Dual Subwoofers?October 01, 2013
Maybe you've been reading about dual subwoofers on the A/V forums and wondering what all the fuss is about. At SVS, we're big fans of running multiple subwoofers whenever possible, and they can be a great upgrade to any home theater or music system. Below are some of the benefits of running dual subwoofers in your system.
Optimal Sound Quality at More Listening Positions
Even with careful placement, a single subwoofer will not have an optimal frequency response at all listening positions in the room. In any given room location, a subwoofer has a unique 'modal pattern' (standing waves with peaks/nulls) and associated frequency response at the listening position. Listeners will often notice that moving even a few feet away from the 'sweet spot' will often result in notably worse bass sound quality. In some places, it will be overly boomy, in other places there will be a “suck-out” where the bass is noticeably less impactful. This is especially concerning when you have a large seating area.
With properly located dual subwoofers, the respective modal patterns will overlap, which greatly increases the sound wave density in the room. The result is a smoother frequency response at more listening positions in the room, with less potential for obvious peaks/nulls in the frequency response. Everyone gets the same room-energizing, heart-pounding listening experience no matter where they’re seated. This also makes it easier for auto-set-up programs like Audyssey MultEQ to equalize the subwoofer channel.
Effortless Bass With Greater Headroom
A popular phrase among the SVS Sound Experts team is "headroom has a quality all its own". Dual subwoofers will greatly increase the available system headroom, providing greater dynamic range, reduced output compression, lower distortion, and less potential for overdrive artifacts. In short, running duals will give you cleaner, more accurate bass at extreme drive levels. If you like to listen at reference levels and crave a lot of slam, impact and pressure from action and sci-fi movies or bass-heavy music, then dual subwoofers are an excellent option, and will provide effortless low frequency output on demanding passages.
Stereo Bass for Dedicated 2-Channel Systems
Discerning audiophiles and 2-channel purists know that directional bass cues are important to imaging and preserving the solidity of the soundstage. Using dual subwoofers in a dedicated 2-channel system will preserve stereo bass cues, and prevent the soundstage from collapsing, particularly when small bookshelf monitors with limited bass extension are being used. This makes for a more realistic and convincing audio experiences where you can pinpoint sounds in space and believe you are on stage or in the studio with an artist.
Harder To Localize
Even with a fairly deep speaker/subwoofer crossover frequency and the associated masking effects of the surround speakers, it's often possible to localize a single subwoofer in the room, particularly if it is not located on the front stage. When properly set-up, bass from a subwoofer should sound like it is coming from each individual speaker and not from a specific location. In comparison, dual subwoofers are nearly impossible to localize. Once listeners experience this immersive bass which seems to emanate from everywhere in the room, they never want to go back to a single subwoofer set-up.
Two Small Subwoofers Can Fit Where One Large Subwoofer Can’t
Many enthusiasts have their music and home theater systems located in mixed use living areas, where subwoofer performance must be balanced with décor and aesthetics. In situations like this, a single larger subwoofer, especially those with ported cabinets, might have too much visual impact in the room or might not even fit in the allocated areas. Conversely, two smaller subwoofers can offer similar performance, less visual impact, and can also fit into more locations in the room. If space is a concern, sealed cabinet subwoofers are generally a better option for discretion. If you’re interested in learning about all the differences between the two types of subwoofers, check out our post on Ported vs. Sealed subwoofers.
Recommended Placement Locations for Dual Subwoofers
Based on our own extensive testing, and research done by the professional audio community, we recommend the following placement options for dual subwoofers:
While the first two options are proven performers with typically excellent results, they are often difficult to implement in a living/family room environment. All rooms are different, so we recommend staying flexible and trying all possible placement options for the best results. - Ed Mullen