Individual instruments having a lack of phase coherency
This is an odd one that I've never really experienced before. Wondering if others have come across this before.
I'm mixing a classical show that I recorded a couple weeks back. I tend to be very careful about phase relationships in my recordings. In this particular case, a pair of MKH8040's were in ORTF as a center pair and a pair of Schoeps CCMK2 (?? small form factor schoeps omnis) were my flanks. I had a number of spots as needed because of some contemporary music on the program.
For the "normal" rep on the show, everything sounds great. The image was solid, both front to back as well as left to right. There were woodwind quintets and a performance of the Beethoven Septet.
There was also this concerto for viola and chamber ensemble (a briliant piece that was a premiere). In the ensemble, there was a small percussion setup. It consisted of temple bowls, a few other hand percussion instruments and a small collection of pitched gongs. For the majority of this piece, things sound great. However, the pitched gongs cause every ambient microphone on stage's phase to freak out. I can have a source standing right in front of the main pair and on a phase scope, that source is shown to be right down the middle. However, when the gong is hit, the phase goes at least 90 degrees out... Bringing in the percussion spot mic helps minimize this a bit, but I have to admit, this is a strange one.
So the questions are- has anybody else experienced something like this? and are there other instruments that have an odd phase relationship with themselves. In sessions, I'm used to brass instruments with a negative slope on the waveform (when played directly into a mic) and some other things like that, but I haven't come across this..