Speaker Wire for Popular Budget System

Okay, I bought the hype regarding the widely viewed YouTube review which recently launched the Klipsch RP-600M into cult status. Actually did twice - First pair of these I picked up are in an asymmetric, long wall HT situation and I have no gripe at all about that setup. To be honest, I have few gripes about the second pair I acquired along with a NAD C316BEE V2 integrated much like in the YouTube video except that, in that configuration, the RP-600’s propensity to transform itself into a bright/forward ear-drill-on-steroids manifested itself early on and gratuitously so until I stumbled upon a combo room treatment/tweeter-damping-with-felt/ high placement with significant upward rake that has this system sounding 85% of the way I’d hoped it would initially. My question is, what speaker cables would you suggest for this “budget audiophilliac” system to tame that last 15% of forwardness in a manner befitting of Internet-reviewer-enthusiasm heaped of late upon this humble rig?

As always, thanks in advance!
Speaker cables are not tone controls. Unless they are defective.
Try a Loki.
It's good that tweeter damping worked. Now you need to treat the room. Use absorbion on side wall 1st reflection points, behind seating position, use carpet or throw rugs.

Size of room, your distance from speakers, where are speakers located? 

Changing cables now will have you running in circles, you'll eventually want to change them again.

yep - barking up the wrong tree looking for speaker wire to tame 15%  brightness - wire will get you maybe 2-3% tilt... if you are going from one extreme to another

you got much more serious problems than wire will solve
…”Size of room, your distance from speakers, where are speakers located?”…

14’ x 24’ dry walled metal barn art studio/workshop. Speakers are 8’ apart on short wall, equidistant from front & side walls (20”-24”-ish depending…approx. 40” off floor on a modified workbench with short, DIY risers which roughly emulate rake degree of Heresy IVs. Usual listening spot is approx 8-9 ft away from speakers.  The room treatment I’ve improvised is a couple of old tapestry things with some extra terry cloth towels tacked on the wall behind each speaker (Does the “real stuff” actually make that much of a difference?). I can’t go long wall……The space is a mix of different degrees of sound reflectivity and fairly crowded with a couple of cloth chairs and the usual studio clutter of easels and plywood drawing boards/drafting table, etc.
How high is the ceiling, is it metal or dryer?

Also, you need to remove the vibration from the speakers sitting on the bench. The speakers need proper coupling to the stand. What substance are the risers made of?

I use a large tapestry on the wall behind me, works well. I think you can do better than hanging some towels.

You may need absorbion or diffusion panels on the ceiling and side walls.

…”How high is the ceiling,…..”…

11’ at its peak…typical, barn style vaulted ceiling (both walls and ceiling are fitted with fiberglass insulation and dry walled).  However, the system on this particular short wall is situated directly underneath a storage loft which is of 3/4” plywood construction with 2”x6” exposed beams.  This, effectively functions as an 82” high ceiling (77”ish high at the beams) above the speakers and out 5’ from the front wall.The risers are wooden and the speakers sit on rubber pads (supplied w/the speakers) atop the risers.  The risers sit atop felt furniture pads atop the workbench somewhat “out on diving board-like structures” ( 26”x 17”x 3/4” plywood) which were affixed to the workbench with silicone caulk and drywall screws such that optimum distance from the front wall could be achieved.

The towels are hidden by the tapestries…lol.  Just experimenting with extra sound absorption material I had on hand.  Luckily, WAF is a nonissue in this particular space!  The main house would be another story altogether but, out here, I can tack up any SQ remedy regardless of visual appeal.
Is this the same speaker here:

Well, I am not sure it's worth the trouble.  The speakers are sold for 699 per pair.  You may end up spending more on room treatments.
That’s the speaker, andy2, and here is the video that started me on this journey with said speakers:


Today I’m smiling about this latest, 2nd pair of them that I bought (for $377 pr. last month on sale!) but, for whatever reasons, it’s taken about 3 weeks more toil, hair-pulling, and research to get them dialed in nicely than this above video-review would suggest.  I am finally at the point of replacing the gratuitously thin speaker wire currently on this system with a $75-$100ish pair and calling it a success but…….whew!
How’s the volume at your listening position? Do the amp and speakers push enough SPL’s?

It seems you’ve done well renovating the interior with fiberglass and drywall. But, this will never work until you cover the storage loft space. You’re losing too much sound.
Can you hang a canopy of some heavy material? Have it drape over your system level with your ceiling.

The volume at listening position is very good, lowrider57…..Not only is it too loud for my tastes before the dial is at 11 o clock, but low level sound is as good as with any system I’ve owned.  
As per your description, I’m interpreting this canopy as something that could be affixed to the underside of the storage loft as a faux ceiling of sorts above the speakers??  Does stapled-up acoustic ceiling tile seem like it might be a similar option?  I’d also thought of experimenting with paperless fiberglass insulation held in place w/chicken wire as the underside of the loft is very much like an uninsulated wall space albeit with varied widths between the beams.  Definitely sounds interesting…
Try some Kimber 4pr or 8pr cables, kinda affordable.
go to RadioShack and buy their 12 gauge Speaker Cable. Comes on a roll of 25ft or 50ft. I have put this in a number of friends systems that don’t want to spend a lot of money.
The RadioShack speaker cable got some very positive reviews a few years ago. I even use this cable in my second system for my surround speakers, using Kimber 4pr for my front speakers, B&W 801’s.
 I also use a $10K speaker cable on my main system.

…”What is your source?”…

Streaming Tidal from my iPhone to an Apple Airport Express which is now connected via Ethernet cable to an eero mesh network (was previously all WiFi using the Express with an old Apple Extreme router in the previous sound system).  This never was overly bright before but the mesh WiFi setup is a new addition.  I have a Node 2i in the main house system I should probably incorporate into this second system just for comparison.
I’m interpreting this canopy as something that could be affixed to the underside of the storage loft as a faux ceiling of sorts above the speakers??
Yes, that's what I mean. It would be easier than building something and it would provide acoustic damping.

Post removed 
Wire will not band aid the bright forward sound, you should dampen/treat the room effectively until you like the balance in your system for your music, once that is done then you can use better wire to pull more resolution out of your system.
Update:  Seems like there is a definite break-in period with these speakers — more so than some others I’ve used although my experiences here are probably not as extensive as a lot of audiophiles who are accustomed to swapping out speakers at the drop of a hat.  I’d been listening to this system for a couple more weeks and, very subtly and gradually, I began to have second thoughts about adding additional room treatment.  Yesterday, I caught myself pondering a very small boost to the treble on the NAD on certain songs. This morning, I took off the felt-padded grille covers and the system sounds wonderful with 95% of the music I’m playing.  It’s certainly unforgiving of recordings with unnatural forwardness but it’s a far cry from being the “ice pick to the ears” it was when I made the original post here.  Thought this might be useful info for the collective knowledge base regarding this speakers/amp combo…