Hard to say. Certainly on the Model 950 and Model 970/1070, they offered an analog bass management solution that was pretty convenient and unique - a rear panel toggle switch provided the option of engaging or not engaging an analog bass management circuit based around an 80Hz crossover point. The Model 990 was the only Outlaw processor not designed from the ground up by Outlaw (being derived from the Sherwood R-965/P-965 platform with some significant hardware and software modifications), and as a result it lacked the analog bass management. Instead, it had ADC's on the 7.1 analog input and applied the same digital bass management used for digital audio inputs. With multichannel audio sources now so heavily shifted to HDMI and some sort of comparable bass management offered by most of those players, the need for including it may have waned a bit compared to what we saw in 2002 (when the Model 950 arrived).