First off, measure your in-room response at the main listening positions. If you have any large peaks then a unit like the ART can be very useful. Another feature of the ART is highpass filtering, which can be set to reduce frequencies below a chosen point. SVS being ported subs, have difficulty playing frequencies under their tuning point. If you filter those frequencies out it reduces excursion, distortion, and the dreaded bottoming out at extreme levels.
The 2 main options are the ART351 - easy to use, and the Behringer FBD - hard to use but much more flexible.