What Power Cords for Rel S510 Subs?

@kingharold - Boring!  Actually, I mostly started dabbling with cables out of a curiosity to see if I could hear a difference with my own ears and my own system.  The end result was yes and a very nice improvement in my system.  The experience didn't convince me to chase a unicorn as that's not my style.

@nyev - Most audiophile cables are beyond anything that I'd consider reasonable.  I started with the $100 Chicago interconnect and proved to myself that interconnects did make a difference in my system.  The result of pleasing enough that I opted to see what difference there might from jumping up the lineup a bit.  I needed out over the price sheet and decided that the $200 Yukon was the best value as the next level up in the same series was $500 and more than I'd ever spend and in the other series the Red River and Mackenzie are both triple balanced cables that are not optimized for RCA, so it seemed silly to pay for a design that was intended for XLR cables.  Audioquest confirmed that double balanced is better for RCA and triple balanced is better for XLR and that all lines will be switching over time to like Yukon to use difference cables for each type.

I did actually chase the unicorn with cabling for my main system l, and am now done with that, after testing loads of cables and driving myself and my family nuts blind AB testing many cables. It’s definitely rabbit hole that once you change one thing, it sets you down a path! Thankfully I’ve emerged from it and my system is better as a result. I now view cabling as a primary component of my system - almost as important as an amp or speakers even, that can make or break a system. I found what many others have found, that speaker cables and signal cables make the largest differences, in a few primary areas: tonal balance, transparency and speed. As you move up in grade I found them to be more revealing. Power cables I found to also impact these areas, significantly, but less so. I found that the difference moving from a middle of the range power cable to a highest end power cable adds space detail and air AROUND the vocals and tones. For me it was the difference between having your system play music vs having your system present the music in a way that seems as if the performers are in front of you in your living room. Interestingly my non-audiophile wife and daughter also noted these differences and (blindly) picked the exact same cables that I thought sounded best. My daughter said “this makes it sound like the performers are on a stage in front of us and the other one doesn’t”. The only problem is, while they clearly heard these improvements, they just didn’t care! Oh well.

Of note, in many cases more expensive cabling didn’t translate to a sound I enjoyed more. I found I didn’t care for the very pricey Audioquest speaker cables (tested Firebird biwire and I found I also didn’t care for the top end Transparent speaker wire. In some cases I found the top end of different brands to be equally good but just a different style of presentation (top power cords from Audioquest and Shunyata). And in yet other cases I found top end cords to be entirely lacking in something (Nordost Valhalla 2 power cord was very obviously missing bass energy of other cords). All verified with blind tests, and all likely results specific to my system.

Very happy I went through that process, but I’m also very glad I’m done with it now!

yes, it is possible to have great cables and great sound quality, without obsessing, and relax and enjoy the music...

I compared cables but stayed within one brand, Shunyata for power and Audioquest for everything else.  Not 100% done.

Considering REL's sterling reputation for building excellent sounding subs I would be very surprised if they risked that reputation by including inadequate power cords with their speakers for the sake of saving a few dollars.  If it were me I would use the stock power cords and spend my time and money on improvements that really matter such as  better preamps, amps, speakers, etc.