@ mr_m
Actually such cables have been made in the past ( TEO Audio made examples of this design several years ago and Bob Smith mentions making a very successful one one in the comments attached to the Dagogo article that introduced the Schroeder Method ). The positive draws of this design are pretty obvious: greater bandwidth, lower inductance and characteristic impedance, but then so are the drawbacks: higher capacitance, and the biggie, instability when faced with high/large complex loads, which btw can become "terminal" with certain designs of power supply.
The capacitance issue in most applications simply means added warmth which is ok( or in some applications glare which is not ok ) but in longer lengths can produce problems ( and super long lengths can produce intractable problems....in industrial settings super long runs of standard cable designs can produce capacitance high enough to make relays inoperative, so one can infer that beginning with a design that doubles capacitance will put some limits on effective cable length ).
But the instability issue is a different kettle of fish. It can, when the two legs are of a significantly different type, produce the lack of synergy that both jayctoy and tuffy have experienced, it can also produce the type of oscillations that years ago put our experimentation with this design to rest. Btw it was during the first discussion I had with Doug about the viability of using this design that this rather negative experience was brought up and that directly gave rise to the warning/disclaimer that Doug has wisely added to his subsequent discussions about the Schroeder Method ( and good on Doug for being cautious when faced with something that has produced such wild results...I think most people would just charge forward, torpedoes be damned...we certainly did and closely skirted disaster ).
So the bottom line with this design is it has some very obvious benefits ( eg lowering the characteristic impedance helps digital signals, greater bandwidth helps all signals, higher capacitance can be a mixed blessing assuming cable lengths are held relatively short ) and some potential problems such as a perceived lack of synergy or a really bad synergy that can escalate into terminal instability.
So while experimentation is much fun lets proceed with caution eh. To paraphrase, its all fun and games until someone loses amp or a speaker.
