Just as a follow-up to my last post where I mention near-field listening, you might want to check out this
link I found regarding this topic:
http://www.whatsbestforum.com/showthread.php?886-Near-Field-Listening-Acquired-Taste-or-Proper-ParadigmCoincidentally, the poster there is also using Harbeth 40.1s and shows a pic of his listening arrangement with the speakers.
I am similarly situated, but my speakers are pulled out into the room more than his - and I set mine up so that wall behind
the speakers is a corner of the room (the 'center' of the stage where the vocals usually come from). On some recordings, you
are oh-so-close to 'being there' in terms of soundstage width, depth, height - and you can close your eyes (or just listen in the dark
like I tend to do at night) and reach out into the sound that does NOT even seem like it is coming from the speakers at all! The
speakers disappear not only because of listening in the dark, but the sound does not seem to come from them - it comes from beyond them.
Just as the link above mentions, by doing so you take a large percentage of the room acoustics OUT of the equation - but not all speakers are designed to sound good listening to this way, and depending on your room and how much flexibility you have, it might not be practical. But if you can - try it! Make sure you precisely measure the distance from your ears to the speakers to within 0.5", as well as play with the angle that the two intersecting speakers (imaginary line) makes at your listening position. I have to do the trig - but I think I'm between 80 - 90 degrees. If you dial it in just right, you will be rewarded!

NOTE: Some may think of "desktop" listening when they hear the term near-field. Fine, but the setup I am referring to goes well above and beyond the sound you'll get from a desktop because there is no desktop in the way, the speakers are pulled out into the room and interacting far less with it, there is a much greater sense of depth and space, etc. It's like studio monitoring, but without the studio / console.
This is just one way to enjoy listening, and in no way am I saying it is the "best" way - only you can find what is best for you. And as your situation and tastes change, change with them. Experiment. Take notes. Take a few days to get out of critical listening mode and just listen and enjoy. Come back to it again later. And have fun!

Vinnie