I almost always practice unplugged, mainly because the overwhelming majority of my practice these days is related to learning music theory (chord tone exercises, modes, etc.) and I like to be able to focus on the fundamentals of learning the fretboard and how that relates to musical concepts. My primary bass has a really loud acoustic tone anyway, so I can hear everything just fine when I play like that.
The only exception is when I'm trying to learn a bass line for a cover song; in that case, I plug directly into track 4 my old TASCAM 414 cassette 4-track, which I use as a mixer with my computer's audio output running into tracks 1 and 2 and the output going into a set of computer speakers with a subwoofer. That setup lets me pan and do a little eq on the audio input from the computer, which helps with picking out bass lines and playing along with songs. I get a really nice tone out of that old TASCAM, and I have a cassette in it so I can record myself playing along with the song if I like (or if I happen to come up with something and want to save it).
-Y
The only exception is when I'm trying to learn a bass line for a cover song; in that case, I plug directly into track 4 my old TASCAM 414 cassette 4-track, which I use as a mixer with my computer's audio output running into tracks 1 and 2 and the output going into a set of computer speakers with a subwoofer. That setup lets me pan and do a little eq on the audio input from the computer, which helps with picking out bass lines and playing along with songs. I get a really nice tone out of that old TASCAM, and I have a cassette in it so I can record myself playing along with the song if I like (or if I happen to come up with something and want to save it).
-Y
