OK. Bass is not like a normal guitar. The tuning might be the same but it is a very different instrument to play.
I picked up Bass in my late teens. Before guitar (I'd been a poor drummer) and developed my own style... as most bassists do. It is both a rhythmic and melodic instrument and NOT just the Lower 4 notes that the guitarist can't reach and don't let any guitarist tell you so.
It
is a loud instrument. The lower notes resonate through floors and walls. You know how the band sounds in the pub toilet....usually better because all the high frequency is stopped by the walls. You will just have to accept that and find a way to deal with it.
Also, why do you want to play the bass. Believe me it's not an easy option if you want to do it well. The technique of playing varies from the very heavy low E or even lower B on a 5 string to the relatively light G string.
My advice is, firstly, don't worry about the sound. Spending money on an expensive bass is not worth it if you have no technique. There are bargains out there in Cash Converters or Argos to get you started. A cheap Fender Precision copy and any guitar amp to let you hear what your playing (just don't crank it up) is more than good enough to get you started.
I'd then if you're serious as Boydie said, go for a Ibanez. Try for one with an active pick-up (pre-amp in the guitar) to make recording without an amp (Direct Inject) easier.
Good luck and enjoy a very under-rated instrument.