Is this the "Fatfinger effect"?

[Bass Viking]

I hang my basses on garden tool hooks that are screwed into the wall studs. Sometimes I pluck the strings while the bass is hanging and notes will sustain longer. Is this the same principle at work as the Groovetubes Fatfinger device?

For those not familiar with the concept, the Fatfinger is a metal doodad you clamp onto your headstock to help eliminate dead spots by adding more mass.

[Trevorus]

Well, that is quite a bit different from a piece of brass. That hook is attatched to your house. That makes for a very solid vibratory base. The body is the weaker of the two. But the effect of a small piece of brass or whatever is negligible.

Think of inertia. It would be really hard to get your house to move (vibrate). Same with the body of your bass in comparison to the headstock of the bass. You would have to increase the headstock mass quite a bit to make a real difference.

But, yes, that is the effect it is going for.

[Pacman]

No - the reason it sustains longer is your body isn't dampening the vibrations of the body. The Fatfinger effect - not a trademarked term - is that the additional mass changes the Q (resonating freq) of the neck. This serves to move any dead spots.