I am helping a buddy with his home theater setup and have run into some trouble. His receiver is an Onkyo TX-NR515 but the in-wall sub he installed is passive. He is ordering an amplifier to power the sub, but I am concerned about the fact that the amp does not have an LFE connection, only line level. What is the best way to connect the passive sub to the receiver? Is there a way to utilize the zone 2 speaker connectors? If I do need an amplifier, should it have LFE or is line level sufficient?
Thank you in advance for any help you can provide.