Should I bother to try a subwoofer?


My speakers are listed as going down to 40 HZ (Dynaudio 1.3 MkII monitors).
There is an REL Strata III available locally that I might snag, try out and re-sell if I don't like/need it. My question is this: since I would not be using this for movies, do I even need this? I mostly listen to classical music, more chamber than symphonic, and occasionally listen to rock, jazz and other pop styles.

Am I likely missing something without that lowest octave? I'm thinking that 99% of the time the sub might not even be in use if it kicks in at 40 Hz.

Any comments, purely theoretical or from experience, will be welcome.
128x128tostadosunidos
Has anyone tried a sub with Sonus Faber monitors?
I have to say, so far I have never heard a subwoofer that I thought I could deal with permanently. It kind of makes the speakers more omnidirectional to my hearing, less point-source, and confuses things a little. But I'm keeping an open mind on this.
The older SF monitors (like my Minuettos) are a tough match for a sub because their upper bass was both elevated (relative to the mids) and a bit ragged. It's hard to find a good place to get a crossover that is both seamless within the mid bass and not too high in overall bass level.

I understand that more recent SF models are quite a bit more neutral in that region, so my comments should not taken as relevant to those circumstances.
Here's the possibly disturbing line from the currrent REL site (the "FAQ'S" section, "6. Which REL sub-bass system is best for me?":

"Acoustically, either the 'ST' or the 'Q' range work excellently in either a hi-fi or home cinema system. However, the inputs on the 'Q' range are slightly more oriented towards home cinema use."

They do say "slightly"...I feel better already. Also notice that they no longer make the "Q" series. My beloved Q150E has all the adjustments one could ask for in a sub: Phase, frequency, level for both input types, and a weird 2 position knob for disco freaks.
Post removed 
06-28-11: Wolf_garcia

"Acoustically, either the 'ST' or the 'Q' range work excellently in either a hi-fi or home cinema system. However, the inputs on the 'Q' range are slightly more oriented towards home cinema use."

That I can understand. But did they actually say "Their downward firing subwoofers are designed for music and their forward firing subwoofers are designed for home theater."?

I highly doubt that.