Thomastik Spirocore H Bass 3/4 medium

I use this as a C string for fifths tuning (cgda), orchestral playing. The pizz sound is very nice, very punchy with a nice growl, I see why jazz players like the string.

I would not advise to use this as a C string however, the tension gets very high making it difficult to bow, it really does not speak easily. The sound is good, strong, but tuned up to a C it doesn't vibrate freely enough, you can hear it.

As a b string it's great though for its power even if spirocores don't bow so easily, the sound is more important for the lowest strings.