I have also taken them apart so I know exactly why they sound like this.
They use a very cheap aurasound car woofer instead of a state of the art midwoofer from the likes of Scanspeak.
They use a very cheap Seas tweeter.
Now what's even worse is they use a single cap and coil as the crossover. Inexpensive ones at that, costing about $20 each.
The capacitor cannot prevent low frequencies from entering into the tweeter. Take a 10Uf cap and stick it on a woofer and see how far the woofer cone moves. This is the energy going into that SEAS tweeter. Put your finger on the tweeter of the Rio and you can even feel the energy! Do it on any other high quality speaker and you wont feel a thing because they use a sharper order crossover slops which are much more phase cohesive. All that distortion makes the sound very harsh and cold.
Now, similarly the woofer has too much highs going into it and also what you get is lobing. With the Rios you have to be sat on the exact spot. If you stand up or sit lower the sound balance changes.
The cabinet of the rio is much smaller than it looks because the walls are too thick. The woofer sits in a thick baffle with no chamfering and the woofer actually needs a bigger volume which is why there's no bass.
Overall it's very overpriced considering the parts they use. If you like their sound, great. If you want high quality neutral uncolored sound look elsewhere.