Are upgraded power cables for subwoofers worth it?

I have a Martin Logan BalancedForce 210 which has a 850-watt class-D switching amplifier. I was feeding it with a power cable from Signal Cable, when I read a reviewer on PosFeed dicuss what an improvement an aftermarket power cable made to his sub, in the bass, but also in the midrange.  I value good midrange and have ML CLXs, which are pretty revealing.  So I bought a Sunyata Alpha NR for the sub (I have multiple Alphas and Sigmas in my system).  Shockingly, it had a dramatic effect on cleaning up my midrange, and the impact on the bass was positive, but not to the same extent.  I hypothesize that this is happening from the NR power cord suppressing any "back flow" of switching noise from the class-D sub amp from getting back into my system's "grid" and hence the other components.  But, who knows?  I just know that I would not go back.

Then I decided to upgrade my cables from my ARC REFSE to the sub from average grade to sub specific (and balanced).  I was shocked again ... they hardly made a difference.  Not sure they made any improvement.

I am a n of 1, but that's my data point ...

-docknow

I have three dedicated line, all are 10AWG wiring from same phase on 20amp breakers to AC outlets, never want any possibility of current limitations on any of the dedicated outlets. Power conditioner with any number of components connected on one circuit may draw much current. Amp/subs on their own dedicated circuit, no power conditioning, amps, subs on same circuit so no chance for ground loops. I've tried many power conditioners with any number of amps via lending library at Cablecompany, every one of them impacted transients to some degree, even with outlets dedicated for amps, while these may bypass some of the pathway of other outlets, they still pass through who knows what. Its my experience amps/subs like direct connection to breakers, I can just imagine 10AWG direct wired  no power cords, fuse, IEC, AC outlets.

@billstevenson - my system is also transparent high quality so am considering REL. Thanks for the tip.

@stereo5 - you had thousands of dollars worth of cabling and power conditioning "just laying around" haha - must be nice - also good to hear that Sandy G would use the equipment too.  I've really been impressed with Shunyata gear

@docknow - interesting situation with the class D sub amps.  I run a high end class D for my mains in my second setup with an XC power cord.  Wonder if an NR would be more beneficial?  I really am in love with those Cardas Parsec power cables for low priced power cabling for amps though.  Seem to just punch way above their price point or just synergize extremely well with my system.  Tried against a $2000 Nordost cable and I preferred it by a mile.  My rhythmik subs have A/B amps so I probably will run XC with them or just some beefy amazon ones.  Right now it's partially just a distance requirement that I've come to need new cables.  The servo subs are working fantastically, although I've learned over the years that "better" can always be achieved if one is willing to pay the cost of entry and the time and effort to test various equipment in a similar price tier.

@sns My studio setup is similar but I still saw a pretty massive improvement using a Shunyata Gemini-8 with a Theta C19 power cable.  I know it seems like the book is closed for you on power conditioning, but if you have anyone near you that has Shunyata gear, may be worth a try again?  I'm noticing the opposite -  improved transients and it's not a preference thing.  I'm an audio engineer and recording engineer so I live on my system and am well aware of how transients are incredibly important for realism on a system and can make or break a good mix when layered properly.  Your setup from your breaker may be superior to mine though?  Interesting how components can be world shatteringly amazing in one system and not work at all in another

@jrareform Perhaps I wasn't clear in that I was only commenting on amps/subs on power conditioners. Vast majority of equipment in my system running through BPT 3.5 Signature with film cap and AC outlet modifications (Oyaide R1). In my demos of amps on PC's, the Audience Adept proved best, still negatively impacted transients.