A slightly different angle...
Agreed, the proximity effect refers to the tendency of a
directional mic (anything other than omni) to exhibit a boost in low frequency when close to the soundsource. By close, we're generally talking about inches to a max of 2 ft. Beyond that distance, there is no proximity effect.
The proximity effect is a direct result of the pressure gradient design of directional mics - most use ports (those little openings in the side of the mic). Those things give you the directional characteristic of a mic by allowing sound to enter and hit the back of the diaphragm, cancelling out some of the sound in a predictable way i.e. in the case of a cardiod, the sound from the rear.
Because of the differing wavelengths of sound (bass is long, highs are short) and the physical dimensions of a microphone, it is possible for a close source to effectively mess with the 'good interference' that makes a mic directional and subsequently exhibit a boost in the long wavelengths (the bass).
Said another, less simplified way, sound not only hits the front of the diaphragm, it travels to the back. When you're really close to the front, there's more pressure on the front than the back because the sound is reduced as it travelled thru the relatively longer path (square of the distance). They don't meet up at the diaphragm quite the same as they would for further away sound sources, where the differences in the path length are minimal.
e.g. let's say the path to the back is an extra 1 inch. When you're 1 inch from the mic we're talking about 1 vs. 2 (to hit the back of the diaphragm). When you're 10 feet away, we're taking 120 vs. 121 inches
Why are only the bass frequencies boosted? The phase errors that accentuate the effect occur on the long wavelengths (low bass)
I'm guessing the reason you like the other mics so much better is because they were omnis. It's hard to say since the venues are different. It certainly wasn't the other pieces of gear that made it sound good. I don't think your recording suffered from proximity effect
[edited for clarity]. It probably rolled off the bottom end (as all directional mics do). That's generally a good thing when recording rock shows from a p.a. but maybe not so good in your situation.
What input setting were you using on your JB3? mic-in or line-in?
btw, proximity effect is neither good nor bad. It's just a characteristic. Some vocal mics are designed around using it - they exhibit a sharp bass rolloff that is effective at removing extraneous noises, rumble, hum and then count on the proximity effect to bring the close-sourced voice back into a normal sound.
The other inference one can make is about the practice of using directional mics in their hats with just the front of the capsule sticking out. By not allowing the ports on the side of the mic access to the sound, you are probably reducing the directionality and changing the frequency response of the mics.
and, also, the effect of accentuating that which is most on-axis to the mic,... the unintended soloists.
My pet project, The Hutchins Consort, sets up in a large U shape as an on-stage presence with the bass on the right, and treble on the left. I can easily manipualte the proximity effect of the 4022's, and really gain some massive bass response, but the classic stereo patterns also accentuate the left side treble players.
Moke - that sounds more like straight up directional behaviour combined with "closer to the bass = more bass in the mix". How close are you getting?
Topic: Proximity effect - what is it, and what affects it most? (Read 3999 times)