Yamaha claranets have always had a rather hollow sound to them. Your upgades on your personal claranet would also have had an effect, especially if, I think I'm reading right here, you changed your barrel. You do have reed placement and ligiture right, but since you are still a practicing musician maybe you should try a higher level reed (maybe a 3). If I were you stay away from Yamaha claranets. if you can, try to find an older claranet that is already well used and broken in. If the claranet is brand new, chances are it will not sound right. I own two claranets, both of which are older and well cared for. My first that i played in school is a french/german plastic claranet that anyone could play easily and have no worries about sound. To this day it is my favorite and i didn't pay all that much for it because it was used. My second is a near brand new wooden claranet that i find to be more difficult to play and though the sound is excellent, it requiers alot more air to play. Still, I find it is a much better instrament than any Yamaha. Your best option os to find an older claranet that someone would like to sell, you might find it a better instrament overall.
I have heard that te Japanese aren't keen on 2nd hand instruments at all, so they're exported to the West. Might it be an idea to contact a music teacher to ask if they know of any instruments for sale?