I’ve tested many in-home demo cables with my Gryphon Diablo 300 and my B&W 803 D2’s, including medium and high end options from AudioQuest, Nordost, Clarus and others. Cables most definitely can make a system sound “right”, or can make things sound totally off.
For a medium range very high value speaker cable, I highly recommend the Clarus Crimson (I’m using the biwire version). I would say the same as others and pro reviewers - very engaging, musical, very good bass, and so forgiving of various electronics. Not the last word in speed but not bad either. I also purchased the Clarus Crimson high current power cord, but I’m not so impressed with that cord (boring, constrained).
After testing Dragon and Firebird cables from AudioQuest, I wasn’t impressed. Not bad but also I didn’t get that sense of cohesion.
For the last word in the most perfect speaker wire I could find, it was the Nordost Valhalla 2’s. These were just awesome. Super fast, warm and neutral, and just does as little as possible to the signal. I just placed an order for these after being happy with my Clarus Crimson’s for a few years. I do think that if you are not trying to correct problems with the tone of your electronics with speaker cables, which I don’t recommend, Valhalla 2’ speaker cables are the last you will ever need. Unless you can afford the Odin’s, which I can’t! The Valhalla’s do so little to the signal that I think if you are happy with your signal chain electronics, I would guess that the Valhalla 2’s would suit just about any gear.
Of note, while the mid and high range of the Valhalla 2 power cord was the most exquisite I’ve heard, I also found the bass to be missing when compared with other power cords from Transparent and other brands.
One honourable mention goes to the Nordost Frey speaker cables. These sounded great with excellent timing and a natural cohesive sound with no loss of bass. They just didn’t have the detail, air, and transparency of the Valhalla 2’s but then again, the Frey’s are a fraction of the price.