The S and V here stands for Sealed and Vented enclosure. These subwoofers are built up with the exact same drivers and amplifiers, just different cabinets. The vented cabinet is pretty large compared to the sealed cabinet so that is something to take into consideration.
1V also comes with a foam plug to insert into the vent making it behave almost identically to the 1S subwoofer, just with some added output in the deep bass due to the cabinet size.
Now in vented operation, 1V will have a lot more output compared to 1S below 40Hz. This output is typically very welcome in a home cinema situation, it is a more fun subwoofer for this use, albeit not as tight and accurate sounding as 1S or in sealed mode. If you can accommodate the big size of 1V and you use it for movies and music, then we do recommend going with 1V as you have both options.
On the other hand, if you know that you prefer the sound of sealed subs, and or don’t have the space for 1V and also mostly listen to music then 1S will be the better subwoofer for your preferences.