Setting Stereo Pair levels

[Elk]

Not the oft-asked question of absolute levels, but instead:

How do I set levels for a stereo pair (X-Y, ORTF, etc.) so that they match?

Of course, "by ear" - but are there any techniques or tricks for getting the levels to match?

[surflounge]

I use this...

[JEGG]

Elk- you raise a number of issues.

1. How to determine whether the two preamps are applying the same gain, while assuming the mic's output levels are identical.

2. How to determine if the "program material" is balanced.

3. Determining whether the stereo image is balanced.

All three of these are related, but independent.

IMO, it's the stereo image that must be balanced-even if the performers are not balanced L to R. That can be done by a combination of looking at level meters and careful listening. In a room, there are often factors that escape attention that can skew decisions. Such factors can include HVAC noise, drafts from the same (especially in large buildings) and acoustic noise generated by lighting and lighting controls, as well as a PA system. Sometimes it's better to listen and not look. Your eyes can deceive you as most of this stuff is invisible. If you don't see it, you often don't hear it, unless you close your eyes. And this sort of stuff is often not symmetrical to your recording arrangements. Make sure your monitors-and preferably headphones-are capable of reproducing very low frequencies. You can get a lot of low frequency material from one cardioid with a relatively high roll off in your ORTF array if it is in the path of a draft, or one side is aimed at a distant HVAC duct, and so on.

The point is that there are many factors which can lead to wrong level settings if you merely dial in gain for equal L/R level readings of "room noise." And just having the program content balanced L to R is no guarantee, either. Looking at meters is only a part of getting a good stereo image.

After recording, you can use various methods of correcting or altering a image, including mid-side processing in the stereo realm, or even simple EQ.

BTW, if the performers are not "balanced," suggest they move, or move and redirect your mic array. If you're doing one mic setup with a number of ensembles, enlist the help of the stage crew and get them on your side. They are invaluable. They can make an otherwise good recording a great recording. It can be the stage crew that allows you to achieve a predictable and balanced recording!

Musicians are often not very visually or spatially oriented people. Sometimes they'll love some alternate seating suggestions, especially when it makes them look better and allows them to hear and see better, too.

It seems like it's the ears, after all, that make the call.

[GKennedy]

Hit your mono button on/off/on/off and see if the center of the image stays central or moves. Also works for getting 2 mon speakers to the same level.

GK

[Elk]

JEGG, you raise the issues I was attempting to inquire about much better than I. This is exactly it. Thanks for your thoughtful response.

Last night I was able to enlist a musician to stand in the center of the group and to hold a single note. I then tweaked the various channels until they were equal. Made sense at the time and when listening through headphones.

However, when I got back and listened with speakers, the image was too far to the right. Panning solved this but this is a great illustration of the issues you raise.

I will have to try the mono switch trick - easy and practical.