I have a very long vibrating length on this 16.75" viola that I got for a very good deal but needed quite a bit of work to get it playable. All strings were so tense and wouldn't sing or be easily activated. I got 75% improvement with using the Karneol A, D, G while adding a Kaplan C string for balance on the bridge. I will try the Spirocore long length next time for the C. Just sharing my string saga <3. Concord Music Supply has great prices and great customer service. I will always shop here first.