If you did not get what Mazer is saying, I will clarify a bit.
The quick answer is no, get the STF-2 or better.
You can never really have enough, but it is very easy to have to little.
Going to little, will not give you the 'WOW' factor when you setup the sub.
Not saying the STF-1 is not a good sub, just saying that the STF-2 is better.
You will have more headroom with the STF-2, to use the gain volume as needed (extra impact, less impact).
Personally, I use a 10" sub just for the computer setup in a 11' x 15' room.
But use the 12" in the HT area (which could be doubled to 2 x 12"s).