A boundary gain feature is something that is included in the design process of the subwoofer and like a receiver, it isn't always effective but most often always used if needed. If it was needed for the subwoofer it was probably already included on the subwoofers controls. There also may be instructions by the manufactor of ways to best optimize the location which is actually most effective, but not always well written or included. I would check your models guide for reference. The Audyssey however does not know the design of your subwoofer and treats every room the same with regards to equalization. Fine tunning of the settings for your crossover, speaker sizes, and levels wlll be your most significant room for improvement. The Audyssey will help to correct and smooth out the subwoofer response in areas otherwise not possible by placement and is most always beneficial.