I swapped a capacitor and the oddest thing happened

Many years ago I was playing with my Focal profile speakers. Trying out cap and crossover mods. It turned out to be a very expensive learning experience. I learned a great deal about part selection, felt tweeters, and how to make a speaker with a bad impedance curve.  :)

But one of the oddest things happened to me during break in. Of course, anyone who believes capacitors have a break-in period, and worse, that capacitors sound different is already suspect in the eyes of science, but bear with me for a moment, because this doesn't go where you expect.

So, of course, with confirmation bias, any question about subtle audiophile effects would normally be suspect. I could be selling snake oil, or I could be deluding myself, especially after all the work and money I put in! OK, lets accept that, 100%. I suffered confirmation bias, but one thing happened I have no firm explanation for.

As the capacitors were breaking in (Mundorf MKP) I started to hear weird surround effects. I was convinced some notes were coming from behind and below my ear. Not possible for me to have confirmation bias here, I had no such expectation, in fact the only time I ever heard anything like this was from Polk loudspeakers with the weird inner cancelling drivers.

After about 72 hours, this effect vanished, never to be heard from again.

So, my point to all this is, has anyone else experienced a similar artifact?

As an experimenter I believe this was possibly the following:

• Some behavior of the capacitor was acting as a comb filter, enough to fool my ear/brain mechanism into hearing things behind me.
  
• I changed something in the room
• There was something akin to ear wax altering my right ear's hearing.