A few years back I reconed some older Infinity speakers. These were speakers I hadn't listened to in many years. So I set them up and was rather disappointed with the base. I played with settings on the stereo and at one point either unplugged one speaker or set the balance to one side and boom, there was the base! The funny thing was the stereo didn't sound like the speakers were out of phase. Well the tweeters weren't. In the process of reconnecting the reconed woofer I plugged it in wrong. Since the tweeters were right the imaging didn't sound obviously out of phase but the base was just like anti-noise, just plain missing. In this test case the speakers were only, perhaps 4 feet apart so interference was a real issue.
Anyway, for the OP this is really easy to check. Reverse the wires on one speaker and see if it sounds better or worse.