Blumlein more or less has to be used up close, because a figure-8 microphone admits as much sound from the back as it does from the front. You have to place the mike(s) where you'll get a good proportion of direct sound coming into the front quadrant, or else your recording will be swamped with room sound.
On the other hand Blumlein has a relatively narrow pickup angle--a tad less than 90 degrees total. In other words, from the microphone's "viewpoint," all direct sound sources have to fit completely within the front quarter-circle. If they don't, you'll get strange effects in the stereo image. (The front lobe of one microphone and the rear lobe of the other one will both pick up any outlying direct sound sources at the same time--but those two signals will be in opposite polarity with one another.)
So Blumlein isn't an all-purpose technique, unfortunately, since in the real world, you don't often have a place to put a Blumlein pair where (a) all the direct sound sources fit within 90 degrees, but at the same time, (b) you're close enough in to get a clear enough pickup.
Still, when the conditions are right for its use, it is the "most nearly perfect" two-microphone stereo recording technique there ever can be, in several fundamental respects. Dr. Stanley Lipshitz gave a very interesting AES paper about this some years back--OK, now I see that it was 23 years ago (shudder)--called "Stereo Microphone Techniques: Are the purists wrong?". (His answer, if I may paraphrase: Not at all.) It's available from the AES as preprint 2261 from the 78th Convention (1985).
--best regards
Topic: Run Blumlein tonight for moe ATL? (Read 2668 times)