Power Cables
If any cable is not capable of providing the current needed for the component, then it will make a difference to replace it with a cable which can supply the current being demanded of it.
If any manufacturer were to sell an amplifier with a cable incapable of providing the required current, we need to find the person responsible for that stupid decision and burn them at the stake. The difference between a low resistance 15A AC cable and too high a resistance 15A AC cable is, like, 10 cents in bulk.
So, the science and logic being used is absolutely true --- a cable insufficient in providing all the current needed (causing a voltage drop significant enough to be a problem) is unacceptable and a better cable can remedy that. I would love to see a measurement of the voltage drop on an amplifier's input AC voltage to see evidence that any stock power cord does not supply the required current and thus causes a voltage drop. It would be extremely easy to capture that data and would prove their point immediately. Where is that measurement?
Speaker Cables
As for speaker cables, again, the scientific logic is 100% corrent! If the difference between the cable for Speaker A and the cable for Speaker B is so great as to significantly alter the performance of the speaker, then there is a real problem. Matching the length of the cable would remedy that issue.
However, considering the components in the crossover are most likely assured to be within only 5% of each other (allowing for a 10% difference between cap A and cap B), then having a cable with a LCR difference of 5% should be fine. For a 14AWG speaker cable, that's like a difference of 10 feet to 200 feet. It doesn't hurt to have matching cable lengths, and it probably makes the user happy to match the cable lengths - especially a type-A user like most of these guys. But having one cable be 25 feet and another 12 feet in length isn't significant enough to matter.
I am one of those type-A sorts of enthusiasts who not only has matching cable lengths for my stereo speakers, I place the amps right next to my speakers and use 10AWG cable for a 2 ft run fromthe amp to the speaker. It is absolute overkill, I know, but my paranoia over the cable being at all responsible for the sound being degraded haunts me every day. I don't recommend everyone do what I do though, because I know I am a freak on this matter and overkill is my middle name.
If any cable is not capable of providing the current needed for the component, then it will make a difference to replace it with a cable which can supply the current being demanded of it.
If any manufacturer were to sell an amplifier with a cable incapable of providing the required current, we need to find the person responsible for that stupid decision and burn them at the stake. The difference between a low resistance 15A AC cable and too high a resistance 15A AC cable is, like, 10 cents in bulk.
So, the science and logic being used is absolutely true --- a cable insufficient in providing all the current needed (causing a voltage drop significant enough to be a problem) is unacceptable and a better cable can remedy that. I would love to see a measurement of the voltage drop on an amplifier's input AC voltage to see evidence that any stock power cord does not supply the required current and thus causes a voltage drop. It would be extremely easy to capture that data and would prove their point immediately. Where is that measurement?
Speaker Cables
As for speaker cables, again, the scientific logic is 100% corrent! If the difference between the cable for Speaker A and the cable for Speaker B is so great as to significantly alter the performance of the speaker, then there is a real problem. Matching the length of the cable would remedy that issue.
However, considering the components in the crossover are most likely assured to be within only 5% of each other (allowing for a 10% difference between cap A and cap B), then having a cable with a LCR difference of 5% should be fine. For a 14AWG speaker cable, that's like a difference of 10 feet to 200 feet. It doesn't hurt to have matching cable lengths, and it probably makes the user happy to match the cable lengths - especially a type-A user like most of these guys. But having one cable be 25 feet and another 12 feet in length isn't significant enough to matter.
I am one of those type-A sorts of enthusiasts who not only has matching cable lengths for my stereo speakers, I place the amps right next to my speakers and use 10AWG cable for a 2 ft run fromthe amp to the speaker. It is absolute overkill, I know, but my paranoia over the cable being at all responsible for the sound being degraded haunts me every day. I don't recommend everyone do what I do though, because I know I am a freak on this matter and overkill is my middle name.