Do I need a subwoofer? Which brand and model?


I mainly listen to classical and jazz - mostly trumpets and violins, with the occasional piano, viola or bass guitar. A couple of my friends have been suggesting to me that my ensemble lacks bass and having a subwoofer will address it. My setup includes a 2 ch. NAD C365BEE integrated amp, Wharfdale EVO 50 loudspeakers (pair), and an Oppo BDP 105 Bluray player as a CD player. The setup is in the living room, with three walls, and the fourth side open to the dining room. The living room itself would have been 18' L X 12' W X 18' H = 3888 cu. ft, but the fact that it opens up to the dining room makes the entire space more like 40' L X 18' W X 12' = 8540 cu. ft. Would I benefit from a subwoofer and which one should I get? Budget $1000 or close to that.
shugho
Thank you all for your comments, all of which are very helpful. I will definitely try adding a separate amp down the line and using the NAD I have as a preamp - I'm glad that is possible. Lloyd, I will take you up on raising the sub - that sounds like an interesting and worthwhile thing to try.

I still am debating SVS SB 2000 vs Hsu VTF 15H vs Hsu ULS 15. My needs are music oriented rather than HT. Any comments specific to these three choices for music rather than HT would be most welcome, to help me with my decision. Thanks again all!
I apologize for not mentioning in the last comment that Bob Reynolds is already recommending the SVS SB2000 over the Hsus for my system. Any other comments specifically towards these three models are welcome.
Lloyd, you mentioned about having setup options. The Hsu VTF 15H offers more options with regard to fine-tuning, according to what I understood from the web site. I am somehow leaning towards this model from a power and flexibility standpoint but also feel that I will be taking a risk with this model. The reason it is a risk is that this model is beind sold at a discount and there is no return policy on it. I feel that the SVS SB 2000 is the safest bet because of their return policies. However, I am leaning towards taking a risk with the Hsu VTF 15H. Not sure if this is the right thing to do. Any help is welcome.
"However, I am leaning towards taking a risk with the Hsu VTF 15H. Not sure if this is the right thing to do. Any help is welcome."

Don't get them both at the same time. Do the amp first, as it may have an effect on what sub you choose. Also, you may find that you don't need a sub with the added power.
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