I don't think one number is enough.
I think it will take at least three.
But the decimal system isn't enough either, or hexadecimal.
So I'm going with fruit.
Each digit can be a fruit ... any fruit. So that leaves it wide open.
For example, the Sennheiser HD 650 is blueberry, apple, banana.
The HD 800 is lemon, cranberry, pomegranate.
The LCD-2 Papaya, cantaloupe, banana.
Easy peasy.