Tuesday, December 26, 2006

Treble Centricty & Stereo Field Localization

Curt Olson asked me to compare the omni-directal and cardioid positions on the multi-pattern NT2000 mics in the parallel boundary rig pictured here. I've quickly made a 3 minute mp3 test recording of clock positions in an arch ~2 feet around the front of the rig. These are not perfectly positioned stations!

It seems to me that treble centricity is one of the key factors we are trying to accommodate with these rigs and capsule orientations.

When the capsules are facing forward and there's a barrier creating 1/2 omni patterns on both sides, the tonal gradation goes from 0 to 90 (from front-center to hard left/right) with 0 being the brightest and 90 degrees being the darkest. (Of course, the field extends further behind and get progressingly darker due both to the polar pattern and the ears providing more baffling as well.) The same 0-90 spread should occur with the cardioid pattern except with more tonal contrast going from 0-90.

The creation of a uniform spectrum across the front of the stereo is different from human hearing. Some prefer the Pseudo Sass's "3/4" positions in which articulated left and right "centers" are created, but this also differs slightly from human hearing because sounds coming in directly from hard left and hard right are the brightest to our ears. So, If I prefer the stereo field to have an illusion of a spectrally symmetrical "vista" across the front with no darker middle, I should like somehing about using the cardioid pattern,.. but someone else go first! Feel free to chop up the mp3 so its easier to compare. Rob D.

Anna Krutzik's three favorites

T4-07
This recording has a really nice full ring on the echo of the nails. It fills up the entire space, giving it lots of dimension. It makes it easy to hear/imagine how far away the nails are. There is also a decent amount of localization between the different dings.

T9-02
What I like about this recording is that you really get a good sense of the entire building. You can hear traffic in the background and other noises giving it the sense that it's in an urban setting. I don't really listen to the dings so much as the other sounds that are captured on this recording.

T6-04
This recording has very good localization throughout, but it's especially seperated between 1 through 4 probably because its location at test station number 4 makes it closer to that side of the "clock."