Weird phasing during mastering

[stuckatwork]

Hey every one,
I'm just finishing up 3 songs for a demo and I'm getting some wierd effects going on when I add eq during the mastering stage. I was wondering if anyone could shed some light on this. I'm using stienberg's q-metric and when I add it on and reduce some of the high end I get a wierd phasing effect, like the vocals are being sung through a cardboard tube. It's hard to tell on my monitors but it's really apparent when I get it out on the stereo. This isn't happening on my masters that don't have the eq added. I've also used waves q10 and it's doing the same thing. If I use the matrix plug can I switch to MS and eq the middle and solve this? Is this phasiness being caused by the eq or is it a problem with my original mixdown? Also, on the vocal tracks I made a copy of the vocal and compressed and high passed only the copy and mixed it back about 1/4 the volume into the original. It sounds great on the mixdown but am I introducing some phase problems by doing this? I'd really like to get to the bottom of this and if anyone can help me out I'd appreciate it.
Thanks,
Jon

 

[MONTE]

Can you post some samples...before and after? It might be easier to help if it can be heard by some of the other great ears around here.

 

[littledog]

I don't know squat about Steinberg, but if the EQ was somehow only getting applied to one side of the stereo mix, that would account for the phasing. I don't know how or why that is happening, but that's my guess.

Does this happen on every session you ever do, or just one particular one? It's possible something might be corrupted in the session itself. Try bouncing the mix to a stereo track (or dual mono tracks) without the EQ, and try importing those tracks into a new session and then adding the EQ. See if the problem still exists.

Is it somehow possible you are adding a mono EQ to a stereo track?

 

[stuckatwork]

Littledog,
You may be onto something! Q metric is a stereo EQ and I'm running it through an insert on the track so I can compare the effected master to other songs. I probably should be running it through the master effects. I would think that the insert on a stereo track should be a stereo insert but maybe not. I'll try switching it up to the master effects and see if that makes a difference. Thanks for the suggestion.
Monte,
It's hard to get a sample up because I'm working on two computers. One at my drummers house that has all our songs, and the one I'm at now, at work. I'll see what I can do.