Soundstage

Could be a faulty IC. One of my balanced IC had a cracked solder connection and caused similar problem. Took it to a guitar shop, got it fixed for $20. If yours are new, I’d exchange for another pair.
Try swapping left for right and see if problem changes sides.

After installation, I have never touched them or moved then so chances of desoldering or cracking of cable is not possible IMO

Swop the connections (L to R, R to L) at one end of the cable, and see if the energy follows the swop. If it does, you know you have some kind of problem with the new cables.

If your IC's have arrows indicating direction, are they both pointing the same way? The arrow indicates grounding and maybe the cables are still breaking in.

@twoleftears ,

Grammar police are watching. Swop=swap.  

@stereo5 
Actually, standard British spelling, which is what I use.
Do you write gray or grey?

Tonight I did not do or touch my system except switching it on and suddenly I find everything in the center again I don't understand this phenomenon  

I was experiencing that same problem the other day, albeit with older interconnects. I finally tried some deoxit on the connections and the problem was instantly solved.

Poor contacts are likely what is causing the channel imbalance.  Try connecting and then disconnecting each connection, work them around some.  That may help.

So the "energy" went left and the "music" went right.
Good one.
Alternatively, maybe you just got much clearer imaging and are hearing things more left and right of center than you had before.

@twoleftears ,

Did not realize you were British, my bad.

lowrider57 said...

"If your IC's have arrows indicating direction, are they both pointing the same way? The arrow indicates grounding and maybe the cables are still breaking in. "

Nonsense.  Sheer, unadulterated nonsense.

Wife swopping or wives who swop the floor?
Sailors who swab or slobs who grob? 
How about swovid tests with swobs?
And to the swOP, glad your speakers are gtg.
Bad connections are always swoblematic.

I'm with lowrider57, nonsense 

I think that it's a groe area

Have had the same issue with Arcam receiver (or believe it is the receiver).
After it warms up, the soundstage drifts to one side due the loss of volume in one of the speakets. Sometimes even accompanied by a subtle crackling noise.
Once I turn the receiver off and then back on, everything goes back to normal for the rest of the listening session.
Could be static accumulating somewhere but not sure. Definitely not IC, as the problem persists when switching between coax and hdmi.

I would have a full electron microscopic spectral analysis completed on the crystals in the metal of each cable, but I would first want to know the square root of the exact temperature (celsius) at which cryo-freezing took place - that will then give you proper wire burn-in and saturation quotients. And the arrows - ALWAYS pay attention to the arrows - especially on the interconnects...

I’m English, and it’s definitely swap.
maybe the OP had a slight and temporary blockage in his right ear that coincided with his cable swap.

Simple way to test; use a Left//Right/Center voice test track . They are readily available for download. You will know immediately wether the soundstage is or is not skewed.  Center image is a range, so play with positioning.  If you have L/R balance controls, work with them.

There can be a bad connection inside one of the connected devices.

Get a VOM and clip leads. Measure conductor and shield end to end on the interconnects while vigorously wiggling the connectors. Resistance should remain ZERO.

Repeat with each connector measuring between conductor and shield. Do both ends of the cable. Resistance should remain infinite.

If the above are true, problem is internal. DO NOT wiggle connectors to a power amp. You run the risk of dumping full power into the speakers. Use a dummy load. 

Hate to say it but maybe your hearing?  I started having a problem over this past winter where the right side seemed slightly muted at times.  Soundstage seemed shifted to the left.  Barely noticeable but frustrating.  It took maybe a month or so to realize that I had some tinnitus starting in the right ear.  Nothing wrong with my gear/setup.  

How loud do you listen?  Could be after a few hours you start having auditory issues

Hello,
You and another person talked about having the same issue. I do like MC’s answer. People forget what their system sounds like. It might be your capacitors. Uneven sound, cracking, and inconsistent times. I am not sure of what your pre/ amp is but caps do go bad and can give off inconsistent sound signatures. Power it up and listen. If it is a tube product it could be a tube. Roll the tubes from L to R and R to Left. If it is solid state switch the IC at one of the ends. Also there can be caps in your speaker crossovers. Switch the speaker wires too to see. Or try the speakers on another device. Sounds like a cap or tube problem.