Daddario KS311W-4/4M Kaplan NW E Med.

I have a tendency to struggle with whistling E strings when changing string quickly from the A to the E. Fo far, the only solution has been to fit these strings. Quite simply, they work.

I play mostly old-time fiddle tunes, and this necessitates a lot of re-tuning and as theses strings are a little more fragile than plain steel plated E strings, you need to be careful to avoid premature breakage. I have found these strings combine well with d'Addario Helicore and Zyex, and also Thomastik Vision and Warchal Karneol.

Although the non-whistling it's wonderful, I didn't feel it has the best sound quality as top E-strings, but definitely nice to try