Arguments for and against head-over-heels operation in vocal recording.
You see microphones being run “upside down” all the time. The upside down is much discussed, among beginners as well as among engineers who hear fleas coughing (and even those who can tell from the coughing of fleas whether it is more viral or bacterial…). So here I will briefly discuss the pros and cons.
Microphone upside down: Pro-argument #1: Waste heat
A major reason to run a microphone upside down is a technical one: the electronics in the microphone produce heat during operation. This heat can transfer to the diaphragm, which then produces a bit more noise due to particle movement, which is stronger at higher temperatures. In addition, turbulence caused by movements of air at different temperatures – as we can observe over radiators, for example – can also produce acoustic phenomena: different densities produce different refractive indices, which can affect the way sound arrives directly in front of the capsule.
Comment: It is almost always only tube microphones that really produce heat to any relevant degree – and even here there are significant differences. This is certainly not negligible – Sony, for example, has equipped its C800G with a huge heat sink that protrudes far out of the back of the housing. However, I myself could not determine any differences in microphone performance in direct comparisons. In a blind test, I couldn’t tell if the microphone was clamped the wrong way or the right way around, even with several signals. However, the mic I did this with (MG UM 92.1S) doesn’t get as warm as some others either. What can be accepted, however, is the “better safe than sorry” argument!
Microphone upside down: Pro-argument #2: Room to move for the singer
If the vocal microphone is suspended from above, the space underneath remains free. This means that a recording is not quickly rendered unusable by the vocalist hitting the microphone stand with his foot or hand and producing impact sound or getting caught in the cable and thus steering the expensive microphone towards the studio floor. This is also psychologically advantageous: some of the constriction in the studio is eliminated, there is room to gesticulate.
Comment: The “perceived freedom” during recording should not be underestimated. It can distinguish a good performance from a stunning one. But I think the safety aspect is more important. Having to throw a great shot in the garbage can, or having to do small-small repairs, that hurts. And a noble tube microphone that has fallen over hurts, too. Oh yes: With a normal microphone boom you can create enough free space even with a conventional setup. And this free space can be used up again excellently, for example by setting up a stand with sheet music.
Microphone upside down: Pro-argument #3: Vocal sound
Sure, a microphone can be angled out of plumb in either direction, but upside-down mics tend to be angled down rather than up. With mics on a simple stand, it’s the other way around. Here, most engineers tend to aim from the bottom of the head. Also, whether the reflections are more likely to come from the ceiling or the floor could make a difference with differently angled mics. Because of the microphone body, especially on large mics, and the “platter” that separates the capsule from the electronics, a typical large-diaphragm condenser mic is also not absolutely rotationally symmetrical. And the human being as a sound source is not either, a part of the signals is emitted by the head and especially by the chest. In this respect, it can already have different effects whether the housing is located in front of the chest cavity and there the metal tube and the internal air volume are excited more strongly. Moreover, tubes are always microphonic to some degree, which argues for taking them out of the line of fire.
Comment: Here it depends on the voice, the recording chain and the desired vocal sound, because the respective influences can be positive. But let’s be honest: The described effects are absolutely vanishingly small. Especially with very sonorous male voices in conjunction with tube microphones, you could try out whether you hear a significant difference.
Microphone upside down: Con-argument #1: The microphone obstructs the eye contact between engineer and singer
True: When you bring a microphone down from above, the singer is staring at the mic. After all, the eyes are higher up than the mouth. So you can no longer comfortably look over the mic at the engineer or producer. And communication is important!
Comment: The eyes are higher up than the mouth? Oh, really? And what if you record a goth singer in vampire style hanging on the studio ceiling? Haha. The more important question in the contra argument is whether eye contact is even desired. Vocal recordings are usually such an intimate affair that most performers would rather be to themselves instead of looking into the critical faces in the control room and feeling watched. It’s more important in recording breaks during reviewing. But again: Is it really that insanely crucial? Rather no.
Microphone upside down: Contra-argument #2: The dear money!
It’s simple: It’s simpler, more stable and above all much cheaper to simply plant a microphone on a straight mic stand than to suspend it from above.
Comment: It hardly makes a difference for a microphone stand with a boom whether it is extended 15 centimeters more or less. However, with particularly long microphones – think of old tube microphones with an angled connection at the base – the difference can sometimes be as much as half a meter. And there are very light and very heavy microphones. Especially some ribbon microphones with large, heavy magnets are most safely suspended with a construction crane.
Microphone upside down: Contra argument #3: Proll factor too high
An upside-down microphone looks overly pompous. This huge effort, when you can just plant the microphone on a tripod…
Comment: Yes, there is something to it. But ego is everything, and some musicians might like that.
Microphone upside down: Contra-argument #4: Distance issue
Some people think spacing is harder with microphones suspended. And distance is important for the sound, otherwise the engineer has to do a lot of work afterwards.
Comment: Slow down with the young horses! You can keep your distance as a singer, otherwise a pop shield helps for safety. And markings on the floor are not only in the movies and on stage!
Microphone upside down: Contra-argument #5: The spiders are not designed for this purpose.
Microphones are usually inserted the right way up into their elastic mounts. If you run them upside down, something can still break or the microphone can fall out.
Comment: Oh, really? Most spiders are screwed tight to the mic or pressed against the body anyway. Whether the weight then pulls “up” or “down” is irrelevant.
Use the mics the other way around: Conclusion
As you can see, many things are not that important, cancel each other out, or depend on the situation. In case of doubt: take your time and try it out, pay attention to the noise and make sure that the person in front of the microphone feels comfortable. As a rule of thumb, large tube mics should be operated in the opposite direction.