Are you looking for the alt/tenor or even more the
baritone depths for this beautiful middle register.
The ideal compromise
It is interesting to note that there is an enormous diversity in the models of violas. Violas have had a changing role in history. Today, one can choose from various models and a wide tone range. When making violas there are many considerations to take into account when attempting to strengthen certain qualities or to compensate for others.
Several models were built by Saskia Schouten, i.a. by Antonio Stradivarius, Pietro Guarneri and several own models.