Well, first, you really need to get yourself a real bass amp/speaker.
First, thanks for all the replies ! I had a Carlsbro Viper 1000 Combo from the 80's, I bought it used for 80Euro and it arrived with shot and too small fuses ... took me awhile to figure out the right ones and it worked again for a while ... I guessed it go to hot and installed two small fans and it worked some longer but then I tired of changeing fuses all the time so I saved the 15"speaker and some electronics and throw the box out ... :-(
I thought I got myselfe 4 12" or 10" plus some horns and built my own ... (never gonna happen) ... so I pay the 'stupidity tax' ...(the lottery) and hope someday I can have two of those speakers from the first >Back to the future< movie ... YEAH ! I'll play the A on a BASS to them and I'm gonna fly !
I have som old headphones, they don't sound good, maybe they're broken or there's something with the cable ...
Sometimes I use the subwoover from the computer-speakers, I think works a little bit better with the bass than the stereo-speakers, its not that big. I actually have an amp, a Behringer Europower 4000, I got it really cheap and I think it works. It has a anoying noise from its fans and I dont have speakers for it ... I tried and put the 15" speaker from the combo to it, but without the box it was so 'silent' and kinde thin sounded, it was worse than the stereo ...
Yesterday I increased the volume of the bass and did some 'soft licking' ... and it worked better than I thougt ... it wasn't easy, my fingers still want to rip the string but thats gonna get better ... its astounding how little it takes to make a sting sing with still good sound... but then there's that physik thing were when I play a not on the A string, the other strings, specially E start to sing too even when they are not hit ... now I can see(hear) the trouble with keeping the 5th string silent ... I guess I have to find some way to silence the other strings or find a ballance to the amp-volume so the other strings are not amped enough to be heard...
Then there's another effect, pushing down my left-hand fingers sounds more than licking with my right hand fingers, actually a lot more, almost that I don't need the right hand to play at all ...