Harbeth Question

I own the P3esrs and have them in a 20x15x8 size room. I have owned the 7s and IMO the P3s are better . Since you are using a sub I doubt you would need anything more than the P3!

bdp24, as a DIYer, I like to have a commercially available speaker that I can use as a performance benchmark. When I built my first pair, I bought a pair of B&W lower end model but decent. I was able to best them quite easily. Now that i am a little more experienced I'd like to get something good. Not saying I can design better than the Harbeth but gives me something to shoot for lol! It also allows me to chill out because when I am pulling apart crossovers it gives me something to listen to. 

Danny Richie designed the GR Research OB/Dipole Sub (the R in GR is for Richie), along with Brian Ding of Rythmik Audio. Jim, have you considered building one of Danny’s OB speaker designs? OB speakers mate particularly well with OB subs, of course, as do planars (ESL, magnetic-planar, ribbon) and other high-resolution speakers.

The C7es3 are great!   What amp and pre? 

room is 14 x 19 x 7ft ceiling (bsmt). Chayro, I agree with your comment, however I already have the subs and I love them. I also build DIY OB speakers and and struggling right now so I was thinking of getting a pair of commercially available speakers to hold me over while I am screwing around with my DIY speakers lol. I was thinking of the C7ES. The model 3 seems too small.

Harbeths are great but the choice of the right model depends on room size and budget.

Room size plays an integral part in which Harbeth model is chosen. 

I think it's the first time I've ever heard someone ask for a speaker to go with their subs rather than the opposite.  Sort of like asking for a car to go with my tires.  That aside, while you certainly don't need the Monitor 40s, you might consider the 7s over the smallest monitor (forgot the model) so you will have a bit more flexibility in case you want to use them subless later on.  But I don't think you can make a mistake with any of their models.  Harbeths are great speakers if you value a natural, tonally-correct speaker, IMO.