My new Upton bass has a neck where under the G, D and A strings it's rounded, but under the E string, the fingerboard comes to a point between the A and E string, and there is a sharp beveling under the E string. I have been told that is what's considered an "Eb neck." As this is my first bass I've owned and I know zip about it, I have to ask what the heck that means. How many different neck profiles are there? Is there any reference on the net that describes the different kind of neck profiles available for double basses?