an internal biwire normally has 4 wires per channel in a common sheath - very little physical space between HF and LF conductors
principal theory being the large current demands of LF and the field that generates modulates the HF signal = degredation
a shotgun typically has common termination at amp ends but splits the HF and LF runs into different cables that importantly can then be spaced 3-4” apart
you can kind of get same effect w two sets of cables, i personally dislike stacking spades and trying to get a gas tight connection and not get shorts at the amp end, hence my preference for shotgun
hope that helps
principal theory being the large current demands of LF and the field that generates modulates the HF signal = degredation
a shotgun typically has common termination at amp ends but splits the HF and LF runs into different cables that importantly can then be spaced 3-4” apart
you can kind of get same effect w two sets of cables, i personally dislike stacking spades and trying to get a gas tight connection and not get shorts at the amp end, hence my preference for shotgun
hope that helps