the right channel was considerably louder than the left and brickwalled slightly - the left channel was lower than the right but didnt brickwall
i taped 4 bands - each time moving posotions in the venue - same thing on all recordings - right channel louder than left
As Guy suggested, they're probably not matched, hence the variance. But there are other variables here: To what positions in the venue did you move? Was the PA was simply louder on one side than the other? Was one mic angled more directly at the source than the other (don't know how you had them mounted / configured)? To get a better sense for how severe the problem is, or for that matter if it's even a problem with the mics themselves, try the following crude test:
- set them both in as close to a single point as possible (e.g. side by side; better yet, place each mic independently in front of the speaker, but only if you can ensure precisely the same position both times )
- place them in front of a speaker on your playback system (best to turn off the other speaker via balance control or removing the cabling)
- play back white noise, or a studio CD, or some such
- record via the mics
- analyze the record levels (and frequency if you wish) from each mic to see how much they vary
Since the mics are basically single point in front of the same speaker, this basically will remove any variances in the playback system or mic configuration that may contribute to different levels. While a fairly crude test, it should at least give you an idea of what's going on, whether the difference in levels you experienced is due to the mics or some other factor.