Very flat but not unpleasant to listen to. Thought I would need a sub due to the small size but there is no lack of bass and I can really hear the detail in frequencies compared to all the lower cost stuff I've used over the years. Well worth the money.
These monitors punch far above their weight. Don't let the small size fool you. They have a very transparent sonic image. Great for audio professionals. I work in TV and these help me deliver outstanding sound design every time. I prefer these over monitors twice the price.
I have been using a pair of this Neumann speakers for mixing monitors. Since they reproduce the music with very realistic sounds, I bought two more for making louder sound with large diameter speakers added for below 150 Hz.