LS70 - less bass "punch" in one speaker

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I have a pair of LS70 speakers that I love. One of them started having less bass "punch" than the other. I swapped cables and also tried a different receiver, with no change. I removed the 8" speakers from each unit and swapped them across, first the mids and then the woofers. The same LS70 *still* had less bass than the other, in spite of swapping the 8" speakers. So...if I rebuild the crossovers, will that solve my problem? It looks like the internal wires going to the 8" speakers are all good, and I don't see any visible issues at their solder connections on the crossover board. Thanks for any suggestions.