Last night while practising bass i was playing a bit of tool, and i heard a song that sounded like he played a harmonic at the start of the riff, and it sustained the whole time while he played the rest of the riff. I tried to do this, but the harmonic faded out very quickly, in fact before i could start playing the riff.

What im asking is, is there any way to make a harmonic louder, without turning the volume on the amp up, or even better, is there a way to make a harmonic sustain itself longer?

Thanks!
-Kirbo

Harmonics should ring for a very long time. It's possible that you might have accidentally muted the string- it doesn't take much to kill a harmonic. And like any note, the harder you pluck it, the louder it will be. Having some highs in your signal can't hurt none, either.

I think on the song "dispsostion" by tool there bassist uses a delay effect, but I could be wrong.

Lift your finger off of the harmonic node immediately after you pluck.

soloing your bridge pickup.. (bridge pup's catch more harmonics than neck pup's)

Fresher strings. Or better IMHO, old clean ones.

Any dirt/grease/stuff on the string will kill harmonics off.

Compressors also work wonders for making harmonics scream out, and last.

A bit of gain or over-drive works nicely in some cases.

Much of it lies in the bass and its ability to sustain notes. But a compressor could help as well.