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 taking the time to help me out. The inputs give me a few things to think about and will help me make a suitable decision. I am inclined to try out a couple of scenarios before I make my decision, based upon the inputs provided. This has been an enjoyable read. I appreciate everyone's help and hope to have a solidly punchy and bassy musical holiday season! Cheers all!
"12-02-14: Stringreen
You don't have to spend that much....subs are not that critical."

Not for you. lol. But the OP doesn't have a pair of Vandersteen 5's.
I need to add the following observations on my situation and ask a few more questions. I am testing a variety of music on my current setup and my observation is that the bass drivers on my speakers are hardly being driven, even with bass heavy punchy songs. I tried to turn the volume up to see the effect that had - the other drivers reacted a lot more than the bass driver. Turning the bass control on the amp increased the bass but not in a satisfactory way - the sound was muffled.

First - I would like to ask (apologies if this is getting repetitive) if this is due to the amplifier- to remind everyone, this is a NAD C375BEE integrated amplifier, at 80W per channel.

Second - my Wharfdale EVO 50s continue to satisfy me at the high end but are practically non-existent at the lower end. Is this a speaker issue? Does anyone have experience with these particular speakers? Should I consider replacing the speakers to get the full sound I seek?

Third - if this is an amp issue and adding a power amplifier to this setup and using my integrated as a preamp is the way to go, can I go with a NAD C275BEE, which is a power amp at 150W per channel? Will that be good enough or do I need to go higher such as a NAD M series? How high should I go to see a distinct difference in the fullness of the sound I want?
Make absolutely sure that you have your speaker cables connected in phase.

Also make sure that your Oppo is set up to play in 2 channel mode, and not something else like 5 channels.

Try removing the jumpers on the back of your NAD and run interconnects from the output on your Oppo going directly into the amp section of the NAD. Listen to the system and use the volume control on the Oppo.