timing sustain in the bass

[Clair Dunn]

Hi all -
Just a simple question, don't want to set off any long arguments.

I'm curious as to the value of timing the sustain of various notes in the
bass to get a health reading on the string, the soundboard. I've heard/read
somewhere in the past that a 17 second sustain is good. But, I don't
remember details--like what note (I'm sure that would make a difference).
I've run across a lot of pianos where the sustain is much greater. I have
been using A1 as a rule.

Anyway, curious as to what the thoughts are on this, and what various folks
consider good and what notes they use for the test.

Cheers,
Clair