I would think you would be able to use the line level output (pre-out) on your receiver into the inputs to the sub and then the line level outputs on the sub back to your receiver into one of it's line level inputs such as Aux1. That way the whole signal goes to the sub where it is filtered, based on the crossover setting, and then returned to your receiver to be fed to the amp section and then to your speakers. There should be no degradation of the signal and you use the sub controls to determine how much low frequency stuff is sent to your smaller speakers.