I've accompanied both electric and acoustic basses (with and without a pickup going to an amp), and reproducing an acoustic is a more demanding task that reproducing an electric. Most speakers and subs---and most importantly, rooms!, to one degree or another, add a little "plumpness" to the sound of an acoustic. An upright bass, played purely acoustically, sounds more like a cello than an electric bass, just playing lower notes. I got to intimately know the sound of a cello from my sister practicing hers at home.
Some of my favorite electric bassists play sometimes using the heel of their right hand (if right-handed) to mute the string, in effect making the electric bass sound more like an acoustic. Listen to Joey Spampinato of NRBQ to hear what I'm talking about. Keith Richards loves his playing, enlisting him for the band he put together for his Chuck Berry documentary, and offering him the bassist slot in The Stones when Bill Wyman left. Joey turned down the offer, electing to remain with NRBQ, a much better band.
