Investing in studio monitors is a good idea when it comes to mixing and mastering your sound. The biggest problem with using any speaker set while mixing sound, even fancy Bose speakers, is these commercial speakers aren’t made with a flat EQ and all have different factory settings. When mixing your audio on regular speakers your mix will be made for those speakers, so if you have a sub and lot of bass and someone listens to the mix on their speakers without a sub it will sound very high pitched . The mix will sound high pitched because the audio was mixed with bassy speakers and you would have reduced the bass too much since the speakers added their own bass.
What Studio Monitors are made to do is give your the most neutral sound possible so that when you mix your audio it will be best suited for all speakers types and you won’t have to worry as much that it won’t sound right on different speakers. It is always a good idea to listen to you final mix on several different system like headphones, car speakers, etc… so you can get an idea of the audio in different environments.