Hi

Well I guess it depends on what you want .
Audio interfaces make it easier to get sound in and out of the pc, I big advantage is low latency, but that will only effect you if you are trying to record live while playing BIAB,

As you say you only use it for play back the answer will depend on how satisfied you are with your current sound, and how you are getting it.
If it is coming from the PC or laptop it will be as good as the computers audio, and speaker system. You may well pass it on to some powered pc type speaker system at this point, from the computers sound output but may be limited to a headphone jack to do so, from a laptop. As they don’t have audio line outs like most sound cards in a PC

With the Audio interface you would still have to pass that hopefully better quality line out audio on to some powered active speakers or amplifier maybe even home hi fi system.

As said above the source sound will be the same , if the original source was midi the quality of the sounds will also depend on the quality of the midi synth that converts midi to wave and audio. (But that’s a different question)

At the end of the day you are dealing with Audio sound, and it will sound as good as the Audio system you use. But needs to be good enough to listen to full band or symphony orchestra playing, or even head banging rock if that’s your bag, without distortion.

Mike

BIAB2021 UltraPlus,AsusN55S1Tbssd, W10/64,Akai EIEpro
Yamaha CVP405,SquireStrat, CoolsoftVMidSynth
Novatation Impulse61 Ctr kbd, Cwalk blab Kontakt

http://mikesmusic.byethost16.com/