It would help if we knew how you currently connect your sources to the ADAMs?
There has been previous mention on these forums of how consumers are keen to purchase near field active mnitors but neglect to budget for a proper audio interface with which they are designed to be used.
The usual solution to your problem is to make use of the EQ/effects abilities of a mixer between your source and loudspeakers/headphones.
You can buy quite inexpensive 2 or 3 channel hardware mixers with basic low/mid/high EQ. These are quite handy as they have easy to use knobs and switches close at hand. Some of them also have a built in USB DAC. Prices start at ~$100.
Alternatively you can use the effects facilities in a software mixer. Pro and semi pro audio interfaces usually come with an extensive suite of effects. My MOTU has something called Cuemix which offers easy to use 7 band parametric EQ, 2 compressors and reverb on all input, output and mix channels. RME and Focusrite - and probably most others - offer something similar. Pretty comprehensive and you can save fovourite presets. However they are less convienient to use (unless you get a MIDI control surface).
On the road I use an NI Audio 2 interface wich is very good value @ $100 for 2 separate stereo channels out but doesn't have an effects package. Instead you get a "free" copy of Traktor. Which you can use as a simple media player if you like - with almost infinite EQ and effects possiblities.
If you don't want to spend any more money at all look for a freeware package that meets your needs. Foobar has decent EQ and effects built in and there are some well liked 3rd party add on components which get quite sophisticated.