I just got a Denon 2900 and am going through the set-up routine. In the audio section where you specify your speaker configuration there is a toggle for a "Special Filter". What the heck is this? The manual gives a very poor description. Something about adjusting for DVD audio and SACD discs that are recorded in 6.0 vs. 5.1, but it doesn't say which way to toggle the filter for which!!!! It also says that with the filter off there may be a 5db boost in bass for DVD's and 15db boost for SACD's. Not neccessarily a bad thing, but it would be nice to know why. Are there any other Denon owners who have encoutered this? Do you know how to use this filer? Thanks.