It's hard to say if you hear an audible improvement with shorter cables. The Goertz cables are pretty neutral in character, and while they have very low resistance, they are relatively high in capacitance which comes more into play with long runs (such as your 20' lengths).
Bi-wiring often improves the sound of speakers. Lowering the capacitance of your cables by shortening them probably won't be audible to you, but it will probably present an easier load for your amplifier.
If you send the cables back to Alpha-Core to be cut and reterminated, invest in their silver spades lugs. They're worth the extra money if your amp accepts spades.
Based on my own listening experiences, my opinion is that you will have to spend substantially more money than the cost of the Goertz cables to do better (probably 3x or more). The Goertz cables offer excellent value for the money, and are fine products in absolute terms.
Bi-wiring often improves the sound of speakers. Lowering the capacitance of your cables by shortening them probably won't be audible to you, but it will probably present an easier load for your amplifier.
If you send the cables back to Alpha-Core to be cut and reterminated, invest in their silver spades lugs. They're worth the extra money if your amp accepts spades.
Based on my own listening experiences, my opinion is that you will have to spend substantially more money than the cost of the Goertz cables to do better (probably 3x or more). The Goertz cables offer excellent value for the money, and are fine products in absolute terms.