Well, if you can measure a drop off of 1 dB below 100 Hz, that's pretty definitive: there's something wrong with your bi-wire cable, go back to the old cables. Perhaps there's some issue with the connectors.
I still think the explanations for bi-wiring being supposedly superior sound like bafflegab to me. But I wouldn't expect it to be *inferior* to the point where frequencies below 100 Hz would drop compared to frequencies above.
I still think the explanations for bi-wiring being supposedly superior sound like bafflegab to me. But I wouldn't expect it to be *inferior* to the point where frequencies below 100 Hz would drop compared to frequencies above.