Are upgraded power cables for subwoofers worth it?

I got in touch with REL about this and they said they had tested several third party power cords and found there was no improvement. I wouldn't bother.

If one believes power cables make a difference with the rest of their equipment why would they not believe they could make a difference with subs? PC’s also affect dynamics both macro and micro. So, per everything in audio, believe what you want to believe, but don’t you think it may be worth your time to at least test the hypothesis prior to making assumptions.

When I asked REL about this, they explained that they didn’t expect it to make a difference, because the subs, unlike most speakers, were self-powered and not passive; but they went ahead and tried a variety of cords and found no measurable or listenable effect. They said that the only reason a power cord would make a difference on a sub is if it's too small to pass the needed current. Their cords pass the needed current, so no improvement was expected and none were observed.

I went ahead and tried with my own sub many times and could not hear a difference.

So, there’s REL making an engineering-theory based argument, plus their trial, plus my trials. Surely, everyone can listen for themselves but there’s always the danger of placebo effect. To each his own in this hobby.

@sns I’m well acquainted with placebo effect, been around the block a time or two over the decades....How one can conclude PC don’t affect dynamics which I could also define as current delivery, just as it does with pre’s, amps, sources is illogical to my way of thinking. I suppose some just aren’t as sensitive to these things as others.

I wasn’t suggesting you didn’t know about the placebo effect! lol. As you mention, a lot of factors are at work bringing your subs together (your special design PC, a 20 amp 10 AWG circuit, placement, crossover settings, high-level REL connectors.) I will take you at your word that the PC’s you’ve designed are playing a significant role among those ingredients. (In other words, if you swapped them out with all those other things in place, the quality would suffer.)

In my case, after doing a bunch of work, I have not had any persistent problems with placement, crossover settings, or other things. My subs, with all those pieces in place, are seamlessly integrated and tight. They measure well. When I experimented with power cords, there was no improvement. So, for me, the argument of "no difference" from a PC is based on personal experience, plus REL saying there’s no reason they can see for it to make a difference in theory nor in their trials.

P.S. I just want to add that, of course, in all cases the cord has to be large enough to meet the current demands of the device, and that a sub will tend to draw more current. That's why, to my understanding a 12ga cord makes sense. A 10ga can be used, but with a 20 amp circuit, the wall wire is 12ga. Still, 10ga won't hurt though it will cost more.

@sns Thanks for clarifying your setup. Since you have dedicated lines for 10AWG wiring, including lines dedicated to subs, I can see why a 10awg PC could help you obviate any possible current limitation, especially if the PC's that came with your sub came with were restricting their current requirements. (When I talked with REL, they explained that their PC's were sufficient for their subs.)

But I have to admit, your description helps me, as I've wired a new room with those kinds of outlets (and a dedicated breaker box), but I have not moved in there yet. When I do, I will reconsider my conclusions about PC's and subs.  In my current room, with a 20 amp circuit, no dedicated outlets, and wall wire that is 12AWG, I could not hear a difference with PC's, BUT that's likely because my setup, unlike yours, prevents me from hearing the benefits that you can hear. My claims about not hearing a difference were probably falsely attributed to the PC.

I suppose others reading this advice might take away the reasonable conclusion that if they have a setup like mine, they may also not be able to hear a difference from a PC (due not to the PC but to the wider system).

My guess is that most people will have 12ga with a 20a circuit. So, for most, a 10ga cord probably won't matter unless they have a high-power sub and an 18ga cord.  But if they have a setup like yours, the PC might matter. 

I appreciate this exchange. I'm learning from it. Advice is always relative to someone's setup, and you've made me understand the difference between your (amazing) setup and my ordinary one.

@sns Thanks for the further clarification about your system. It is elaborate and it sounds incredible. Based on what you've described -- plus, I think your ability to hear differences, which may be physiological or may come from your system -- I am sure that I would not be able to hear half the differences you do from an expensive PC. I have many more useful places to improve my system, first! After that, I'll try again. For now, it would be like dropping Waygu beef into cheap marinara sauce. Thanks for a look into an Olympian system. By the way, a long time ago, I had a look at Robert Arrington's system...it was amazing, too.