I guess there is no analog bass management. It doesn't say anywhere that there is, so I guess that means that there is not. I noticed that 1070 specifically states it has analog bass management.

A less expensive solution for your sub would be to use a crossover between the 990 and your amp. Here's a product that should do the trick for less the $100.

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=248-664