The 990 will apply bass management to the 7.1 Direct inputs in exactly the same manner as it applies bass management to other sources. That means that when the front are large and the sub is LFE only, a stereo source played through the 7.1 Direct inputs goes to the mains only (nothing crossed over to the sub). Likewise, a stereo source played through the 7.1 Direct input when fronts are large and the sub is L/R+Sub will send full range to the mains and produce a sub signal from the mains. The one case where the latter would not be true would be if all speakers were set to large, in which case the 990 does not apply any bass management to the 7.1 Direct input (even if the sub is set to L/R+Sub).