Untunefull low b

[charic]

[quote name='JohnFitzgerald' timestamp='1353527593' post='1875712']
I've had experience of a pretty untunable B string before. In that case it was an old and utterly dead string which had zero overtones or harmonics left in it. Pretty tuneless thing with no music left in it.
[/quote]

Sounds like a bass drum

[4 Strings]

With it going sharp, I'm wondering if the string is not of sufficient gauge, perhaps an E string tuned down and so is rather flappy. This would give these symptoms. Do you know what the gauge of that string is?

It's certainly unlikely to be the actual bass.