synthesis of 'harmonic support' for a singer using bass arpeggios

i was guessing to which forum this thread should belong: it could be placed under 'feature request' or 'soundfonts' and it is too 'dummy' subject to fit either of them.

i used musescore ver.1.3 with TimGM6mb.sf2 for long time and even got used with those sound rendering artifacts were present in year-third-ago. but then me upgraded to musescore ver.2 and it brought FluidR3Mono_GM.sf3 with it which sounded wonderfull.
i was distracted by some typesetting artifacts in ver.2 which resulted from my primitive editing skills probably and then downgraded to ver.1.3 again. that was until my system upgrade to xenial ubuntu when me decided to continue my work with musescore *even with those typesetting artifacts (or maybe to overcome that issue with my line)*.

but there was some feature that wondered me very during my first attempt to work with second version: its soundfont sounded very differenly from sound i used to live with using my ver.1.3 compositions. i wrote some music and that was intended to be performed exactly like musescore sound rendering engine does perform that.
me is a bassist and our group performs ambient music. i wrote my bass lines in absense of other group members. and it was very convenient to use rendering to perform together with my computer.
there were two lines mostly: soprano and electric bass. and that was great. bass played arpeggios alongside of synthesized vocals (or soundfont vocals if you wish) and that was real support to me. i intended musical school for a year (long ago and seldom) but that was no oh so useful to my attention capabilities.

in version two i tried sf3 which was definitely better.. but it sounded *MUCH LIKE REAL BASS WOULD SOUND*:
there was attack and was sustain and then was release;
there was no that quality of sf2 font which gave such harmonical support to my soprano line --bass faints at each note now.

but sf2 produced infinite tone (much like guitar compressor would do) --that was a harmonic value of my instrument.
that was really outstanding tone for our particular style too.
certainly sf2 is not to be compared with more evolved sf3 format but how can i get that atmoshere of *harmonically correct support* from my bass-line arpeggios?
is that possible with sf3 to tweak some compressor or to modify tone in other way?