Fun With Stereo Pairs!

    • January 21, 2023 at 2:27 pm#4424
      Mary Mazurek
      Moderator

        Stereo Recording Techniques

        I love stereo pairs, and they’re not just for classical music recording, think drum overheads, pianos, choirs, sections, etc. This past Thursday I took my Classical Music Recording class through a series of stereo pairs. I also had them work with the acoustic of the recital hall at the University of Lethbridge by balancing the direct and ambient sound through placement.

        What you see on the stage are the following stereo pairs: coincident, near coincident, and spaced pairs.

        Coincident pair consists of 2 identical, directional microphones (not Omni) with the diaphragms in the same space and angled some degree. In this instance the diaphragms are 90 degree, so they might be referred to XY as well as coincident. This pair is mono compatable

        as the sound reaches both capsules at the same time. The overall sound tends to be present and maybe even a bit bright due to the fact that the capsules are next to each other.

        The next pair is near coincident pair with 2 identical directional (not Omni) microphones spaced a few inches apart and angled some degree. This pair is 20cm (About 8”) and 90 degrees so this pair is known as DIN (Deutsch Institut für normung or Deutsch Institute for Normals/standards). This pair is not mono comparable due to the space, but this pair creates a great sense of depth and spaciousness.

        The other pair is a spaced pair. The microphones can be any pattern but Omni is commonly used. They are spaced several feet apart, and pointed directly at the ensemble. These provide the greatest sense of width across the stereo field.

        BlumleinWe then decided to add a closer pair to the guitar using two Royer ribbon microphones. Ribbons are inherently figure 8 (unless the housing is changed), so they are great microphones for the Blumlein technique, 2 figure 8 pattern microphones 90 degree with no space in between. These also fall within the coincident pair family.

        We then compared, contrasted, and blended the various pairs. I believe that we found the close Blumlein pair blended with the spaced omnis the most pleasing in this circumstance. Though this combination is not mono comparable, it was pleasing. We still check all combinations in mono. We expect a bit of loss in airiness in mono as that component of the sound is created by the space between the microphones, but if it’s changing the frequency response more drastically, you might rethink your mike placement.

        Binaural

        And because we could…Meet Fritz the Neuman KU100 binaural head. We wanted to find out what 6th row center (an ideal audience listening position) sounded like, so we employed Fritz for the task. The binaural head is spatially accurate over headphones, but he’s sometimes also used for rear surround channels.

        We found that we liked our stage miking better than listening in 6th row center as it provided more detail, but not so much that it sounded unreal.

        So there are some of the basics for stereo pairs. What stereo pairs have you tried and in what context?

      • January 21, 2023 at 6:19 pm#4430
        Bob Katz
        Keymaster

          Cool. I’ve used Blumlein with Omni outriggers to extend the angular pickup. Technically, it’s verboten when there’s audience applause you want to pick up on the back but since the back side of the Blumlein is inverted polarity but the omnis are not you’d think they wouldn’t mix well. But if you space the omnis wide enough the cancellations are vague and random enough so you still get a pretty specific stereo applause track! It can sound great. Use your ears and listen for anomalies muting and unmuting the supplementary omnis.

        • January 21, 2023 at 6:25 pm#4431
          Bob Katz
          Keymaster

            There are some transforms available between binaural and miking for speakers. I recorded a jazz ensemble with my own custom binaural head. And I have access to all the close mikes. The piano is too soft and distant on the binaural. The question is whether I can convincingly mix in the close mikes to get a binaural mix. I’ve had to table the project as it’s too challenging right now to find the best tools for that.

          • January 31, 2023 at 11:30 pm#4498
            Michael Heitmanek
            Participant

              Has anyone tried the bluberry mics in ORTF set up?

              • February 1, 2023 at 2:34 pm#4535
                Mary Mazurek
                Moderator

                  Hi Mickey!

                  No I haven’t tried ORTF (17cm, 110 degrees, cardioids), but I have with other large diaphragm cardioid condensers. It should work just fine.

              • February 3, 2023 at 10:12 pm#4707
                David Streit
                Participant

                  Great post! I completely agree that stereo pairs aren’t just for classical music recording (although that is the context in which I really learned about them.) This week, I used a spaced pair of cardioids to close mic a piano (SM57’s that worked very well in the specific context), an ORTF pair of cardioids for drum overheads and a small choir (Mojave MA-201), and an ORTF pair of cardioids for room sound (Ear Trumpet Labs Edwina). They all sounded great. A well placed stereo pair can add a sense of depth and realism to a recording.


                • February 3, 2023 at 10:47 pm#4709
                  Mary Mazurek
                  Moderator

                    Thanks David! And you’re so right, they produce a nice field of depth as well as width.

                  • February 3, 2023 at 11:01 pm#4714
                    Michael Heitmanek
                    Participant

                      I am not a professional recording engineer, but I have found that a pair of cardioids, large condensers of small diagram condensers in ORTF configuration work well in a lot of situations, especially if you’re recording in a small space. You might have to move amps and instruments, but it gives an over all good impression combined with spot mics. I am a bigger fan of Mid-Side recording. What kind of stuff do you record David?

                    • February 4, 2023 at 1:12 am#4722
                      David Streit
                      Participant

                        Hi @Mickey242! I use ORTF a lot. (I often eye-ball the setup, so I guess it’s near-ORTF.) Mid-side is good too. One cool thing about M-S is that the mics don’t need to be the same, which allows some interesting combinations. I record a variety of pop music (as opposed to classical, although I would enjoy doing that too.) Mostly multi-miced, multi-tracked stuff, often with group members all playing together at the same time, and then some added overdubs.


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