Help with kef r900 issue

I have a pair R700 with the same coaxial unit.  I noticed an issue with some female vocals for the first 200 hours or so but only on mediocre pop/rock recordings. There was a bit of a metallic etch to the voices, almost like they were distorting, but I don't hear that anymore.  I listen to classical mainly and they sound great.  Very clean with great string tone. I did notice the internal jumpers may not have made full contact as the knobs had backed off due to cabinet vibrations.  I installed jumper wires instead.  I don't know for sure if extended break-in or the jumpers solved the problem.  

Thanks. 

@rotarius After resetting the rotaries several times, there is no change. Your description of a metallic edge is how it starts but it immediately degenerates into nothing but a harsh noise.  As you say, classical music is lovely. 

When I first started reading about your problem I thought that you should check that Link Connections are tight or replace the wire with thick basic OFC copper that can be bought for quite cheap price.

However when I read the last posts I can tell you it is the speakers you don't like and there is most likely nothing wrong with the speakers. I have one CD I personally like a lot and once I listened to that CD with a friend and he said that the female vocals on that CD are ear piercing for him and he can't stand it on higher volume. No one else hasn't complained about that particular CD but that one friend and I haven't experienced that at all with any of my CD's.

In my experience KEF's Uni Q driver is really accurate (I own R500 that has the same Uni Q driver as R900) and if you are sensitive to high frequencies you might face some uncomfortable situations with some recordings. Most likely the Logans you used to have smoothed the high frequencies and were more to your liking.

Sorry to hear about your situation - must be extremely frustrating. Hope it gets resolved to your satisfaction.

BTW which particular mary chapin carpenter song is the worst affected?