I just purchased and have done some preliminary listening to the ARC plug-in, using Pure Vinyl as the host application and playing my iTunes library. This is software designed to measure your in-room response at the listening position and then adds eq and phase/time adjustment to the signal to compensate for your speakers/room.
http://www.ikmultimedia.com/arc/features/Initial listening is that it makes a huge difference, probably 85% positive & 15% negative. The sound is more natural, and imaging is much more focused, but there is a loss of air and general ambiance. There is also a slight "digital" quality to the sound.
I also have room treatments, but seeing as how this cost around the same as one bass trap, it seemed like it was worth trying it out. I plan on doing some more testing, and figuring out if I can strike a balance between the positive aspects compared to the negative. I'm guessing best results will be obtained by getting the room and speakers close too neutral, so that the plug-in is doing minimal processing.
A few drawbacks are that it is limited to 96 kHz, and it is either all on or off. I have a feeling an adjustable mix of treated/untreated would provide a more tunable individual result. There is no easy way to change the target eq fro the four curves provided. And it needs a host application that will run AU or VST plug-ins.
It is normally a $450-$500 street price, but JR seems to be closing them out for $315, with a $40 gift card, so final cost is around $275 plus shipping.
http://www.jr.com/ik-multimedia/pe/IK_ACPLUGHCDIN/Jim C
