agree with Batsbrew..
Used to fight (and loose) to get a mix loud...guess it takes mastering skills (and gear/software) to get a mix loud while still sounding good.
But don't let that make you feel bad, the stuff you compare it against is probably mastered.
If you can get a mix to sound great peaking at fe -5 or 6 db, you're done and completed a proffesional mix.
Mixing is about sound, volume is a part of mastering like Batsbrew wrote.
My monitors have plenty bass, but sitting in front of them I don't hear it really. From the other end of the room facing the speakers sideways, I get a better idea of my bass level.
Most monitors are not ideal to hear the tone/sound of your bass, I'd try headphones at a low volume for that.
Why not try to learn your KRK's better, would be my advise...a/b your mix with a reference song you know well.
To get a very good setup for monitoring bass (volume and tone) would cost you expensive speakers and a well treated room.
And then you'd still need to check your mix made on highend / audiophile stuff is ok on consumers playback gear so your KRK's would be handy then.