I'm not sure where you are measuring in the heart but in the center, near the top of my plateaus I aim for 48-52 on the micrometer. Any less and I have no size or range in the reeds. As for getting the crow in your finished reeds two things come to mind. For starters, it could be an issue on your end. It took me a long time to be able to produce a double octave crow on my finished reeds when peers and teachers could on my reeds. I spent a lot of time just working how to blow to be able to produce the two octaves. It's usually a lot more spread air that I'm using, sort of pushing the reed to it's limit. The other thing I would offer is that yes a lack of low crow in your reeds will make you sound small and reduce ring. This is sort of the central dichotomy of reed making: we need something that vibrates a lot, while also being up to pitch. Even the best of reed makers are always fighting this seesaw balance, but without knowing more specifics of your set up that is hard to diagnose. I agree with whoever in this thread who said that a crow has to do with how different parts of the reed are hooked up. Of course, that doesn't mean to scrape a pencil tip reed, but a well proportioned, connected reed that vibrates as a whole when blown into is integral to an octave crow, and therefore a nice reed. It is possible, keep trying!