Speakers must be a perfectly matched pair, so no, this is not right. That said, room dependency could have an effect on the sound of one speaker vs. another at the same position, but it shouldn't be so drastic. You can check this by listening to the sound very close to the speaker (thus minimizing room effect).
I would also check each driver in the offending speaker. . .could be a blown tweeter on the "flat" speaker. Perhaps this is a fuse protected driver and can be fixed for a buck or two. You mention bi-wiring--check the connections for the HF side. . .maybe switching the speaker wires themselves is also in order. If the "flat" moves from one speaker to the other when you make this change, it could be a defective wire or just a bad connection at the amp end.
If you exhaust all these ideas without success, it may be time to return the speakers.
I would also check each driver in the offending speaker. . .could be a blown tweeter on the "flat" speaker. Perhaps this is a fuse protected driver and can be fixed for a buck or two. You mention bi-wiring--check the connections for the HF side. . .maybe switching the speaker wires themselves is also in order. If the "flat" moves from one speaker to the other when you make this change, it could be a defective wire or just a bad connection at the amp end.
If you exhaust all these ideas without success, it may be time to return the speakers.