They are two very different devices. The PARC is an analog bass EQ system. In concept it is similar to the Infinity RABOS or the EQ function Vandersteen uses in their Model 5 speakers. These devices can successfully remove room induced bass frequency "humps" which not only smoothes out the bass response, but also provides for increased transparency through the midrange. The TACT is a digital device which works over the entire frequency spectrum and not only corrects frequency irregularities, but also corrects for some time anomalies. The TACT is a more ambitious device than the PARC and it is clearly more complex to setup and use. The TACT has a very steep learning curve.
Either the TACT or PARC can affect a small miracle in a well setup system. If you system is analog based, then the PARC makes more sense. However, if you have a digital setup and are willing to take the time and effort to properly configure it, then the TACT can do what the PARC does and more. Like any EQ devices, if not used properly they will seriously screw up the sound of your system. I've been using a TACT for close to 2 years.
