Recommendation for an audiophile speaker cord that is not "bright"?

I agree with audioman58. Triode Wire Labs cables are very natural sounding cables. I replaced much more expensive speaker cables with the American Speaker cable. In fact, I recently took delivery of a pair of speakers with dual binding posts and am currently breaking in the American bi-wire version. Pete is a great guy to deal with and will give you a trial period. 
On a side note, his phono cable is fantastic and works well with my Lyra cartridge.

I recently purchased a pair of Canare 4S11 speaker cables from Ram Electronics for 106.00 for the pair.  Still breaking them in but they have already bested my $1500.00 speaker cables I was using before the switch.

Well all I can say is the recording engineers whose work you want to accurately replicate used plain old copper wire and none of this fancy garbage sales people have talked you into. Have you tried a blind test on these things to figure out efficacy? Get some plain old zip cord and then get your fancy cables. Have someone blindfold you and then in no particular order switch things around and just see if you can identify what is being used.

From the aging OP:

I finally decided to make my own speaker cables from Mogami wire as per the YouTube video- they sound the best of everything I have used, except that I lack enough bass (probably the ARC tube amplifier? I do not know). 

I did not follow the plans on how to make a Transparent Audio reference speaker cable, which are also online,  because I think that is unethical, and frankly, I do not have the skills.

An expert at my dealer suggests switching my McIntosh preamp for an ARC preamp. Any thoughts?

P.S. - I also made an XLR cable using a YouTube video - it was a big accomplishment for someone like myself, although I used to build Heathkit amplifiers as a kid.