What power cord are you using on your Vandy 5A's

I am using the stock cords, as recommended by Richard Vandersteen. No other cord has ever made a discernable difference. It is very difficult to detect subtle changes in the 18-100 Hz range. I would not spend money here, but on the source cords instead.

Monk, I am very curious about the differences you heard with power cords on the 5As. While I agree that the setup, room, and overall system synergy is important, I have not been able to detect anything similar to what you report.

One possible difference is that I have separate dedicated lines to each component, including each 5A, and the 4 lines leading to the source components are on a 4kva iso transformer. I believe this may reduce the sensitivity to the AC cords, but I have no absolute proof of that.

Also, I have read studies that show the ear is not capable of resolving the location of bass frequencies below 40 Hz. That would mean that much of the location dependencies you are hearing are in the upper bass or in the bass harmonics. So there could be a relationship with the primary amp as well.

Since there are two identical subs, why not try one with a stock cord and one with an aftermarket cord, play music in mono, and alternate between channels to evaluate any difference? I will give this a try myself.

I fully agree with your description of the localization of the bass in stereo sound staging, and I can hear that in my system. I'm just not sure it can be accomplished solely due to the fundamental, and I'm still puzzeled why a PC would affect it as you describe. I also believe a change due to a PC should be at least partially identifiable in the mono signal (exception of 3D effects).

Yes, the 5As have the best subs I have ever heard and they are the most tonally coherent speakers I have ever heard. A killer for sure with or without PC upgrades.