A couple of quick thoughts:
1) pull the Onkyo out. The CD and Phono should be running directly to the pre-amp.
2) make sure the speakers are in phase, positive to positive from the amp to speaker terminal on both. One might be flipped.
3) make sure the speakers are positioned correctly. Start a couble of feet from the side and back walls. There are a lot of articles explaining setup and bass nulls and peaks.
Report back.
1) pull the Onkyo out. The CD and Phono should be running directly to the pre-amp.
2) make sure the speakers are in phase, positive to positive from the amp to speaker terminal on both. One might be flipped.
3) make sure the speakers are positioned correctly. Start a couble of feet from the side and back walls. There are a lot of articles explaining setup and bass nulls and peaks.
Report back.