kemela carries two American and two European brands of cables with a long experience of the sonic characteristics of all of them. The potential permutations of analog/digital interconnects, speaker and power cables make it difficult to get the right combination. kemela can steer you to a short list to try out taking into account the room, predominant type of music played, performance level of the equipment, and your preferences. Cable choice will depend on the layout of speakers and equipment and the lengths required. Avoiding overly long speaker cables is always beneficial. There is no doubt the effort is worthwhile resulting in a better sound not just a different one.
High quality cables take longer to manufacture under much more tighly controlled conditions using more expensive materials and more sophisticated manufacturing methods. Higher level cables are made in much smaller batches.
There is no hard rule but generally in proportion to the performance capability of the components. A $500 consumer grade receiver is likely tuned to sound best with the performance characteristics of low cost cables and high resolution cables may reveal the limitations of the equipment. The converse is also true, using $50 speaker cables on $5,000 is unlikely to make the speakers sound their best. The point of diminishing returns is when it makes more sense to go up to the next level of components - but - upgrading components while retaining lower performing cables happens more often.
Buying loudspeakers or a complete system from kemela gives you the opportunity to optimise its performance with your music in your space. For local customers we are happy to loan some broken in speaker cables (standard lengths only) during equipment break in and you can either stick with these or try out some better ones. We can also offer you better "package" pricing. For established existing out of state customers, we can work with the manufacturers and do the same in most cases.