Audioquest or Nordost for speaker cable

You could go either way.  They're both excellent brands.  Suggestions and recommendations from others to get you started has it's place and can be very helpful, to a certain extent.  However, there is just no replacing in-home auditions on your own audio system, in your own room.  Ultimately, that's the only way for you to be 1000% certain you made the right choice.  Happy listening.  

I have not used AudioQuest in years so I can’t give any input on their cables, but use their Edison outlets and am very happy with them. I’m sure the AQ cables are great nonetheless. In my experience with much older generation such as Lapis, Diamond and Sterling, they did not muddy the sound. 
 

I use Frey 2 speaker, XLR IC’s and in my system they sound great. I did bring home a Heimdall 2 XLR  to compare to my Frey 2 and took them back - the Frey 2 to my ears was superior . If you enjoy your current Heimdall, I would be surprised if you didn’t find the Frey 2 an improvement. In the Nordost line that is probably as far as I’d go with your system, as not sure the money for Tyr would make sense. 

Well guys your excellent advises and lots of thinking has convinced me to stay with Nordost. I almost went for Valhalla 2 but held myself back as the price was too rich for my wallet. Then I started look at Tyr 2 but same as before too expensive so I just ordered Frey 2. I hope I made the correct decision and will not be disappointed. Thank you all.

OP Frey 2 are excellent , they are definitely better than Heimdall 2 provided if it will match your system.

I have found the lower tiers of Nordost to be just OK… but once you get to Valhalla and up they are outstanding. I only have experience with new AQ power cords. My evaluation AQ wire was long ago, and at that time was not good. But a lot has changed with them.