Please comment on my lighting

Greetings,
Trying loop lighting technique here. Comment please...

Very Interesting.
Very good exposure and very good composition and pose. The background is OK. I like backgrounds to be darker than the subject as opposed to the bright white backgrounds. However, there is a small problem here with the tonal merge between the background and the hair. That can be cured either with some elaborate addition of hair lighting from behind or be choosing a lighter background.

Color balance seems to be exactly on the mark.

Regarding the lighting on the face - this is quite good. Looking at the shadows, we have some in the inner corner of his right eye and we have a really good shadow of the nose and just a little shadow on the underside of the chin and of course the large shadow on his left cheek - all of which create the 3-dimensionality that give the face depth and contours. There is just the right amount of highlight on the left cheekbone and nose and chin to accentuate those contours and the left eye socket has enough shadowing to show the contour of the eyeball.

My only suggestion for the lighting would be to have it arriving from a slightly higher position, thus giving the shadows a bit more of a diagonal throw rather than horizontal.

I am curious as to the source of light because I see a long horizontal catch-light which seems overly large.

Very nice picture, because of the good lighting and the softness of the lighting, which is very flattering for most portraiture.

Greetings,
Thanks Robert for your very detail comments, I'd learnt more from you than anywhere wise.
I agree with the lack of seperation of hairline and background. Now I have to get a barn door, so I can position my second light better without spilling light onto the background .
I placed my lightbox horizontally along my girl's rightside, with she sat on the end of the lightbox. Thus, a long catchlight appeared in her eyes. I'm trying to use a single light source both as main and fill light. It seems to work in this case. But as you said, it a bit too low. A higher lightsource will make a nicer triangle shadow.
Thanks again. Hope to learn more from you again. Enjoy...

Once again, Robert is spot on. I would just empasize the problem of hair blending into background. Generally speaking, this is a lovely portrait.