Poor quality sound coming from one key only
I picked up this old upright piano and have been attempting to slowly bring it back in tune. I've been moderately successful with a tuner app, a hammer, and some rubber dampers but my knowledge ends there.
E6 has this unfortunate crunch to it, like the strings are hitting against metal or something. It is much more obvious in person than in this video, but I was hoping this would be enough to get some possible diagnoses.
Thanks!