Proximity Effect.... (I love it!)

[Bruce Swedien]

Proximity Effect

 

Is an increase in low frequency response as the sound source is moved closer to the microphone

 

Proximity Effect in audio is an increase in low frequency response as the sound source is moved closer to the microphone. Proximity effect is actually a distortion caused by the use of ports to create directional polar pickup patterns, so omni-directional mics are not affected. I have never thought of Proximity Effect that way.

 

To me Proximity Effect is more like distortion free EQ.

 

When I recorded Michael Jackson singing the lead vocal on

[Bookumdano2]

Hey Bruce,

 

Do you ever find a preference of using an omni on a single voice to defeat proximity or reduce it? I've never done that myself but I notice others saying they sometimes like the overall effect of an omni on single point sources.

[blue2blue]

Well summed up, Bruce!

 

Like you, in terms of everyday practicality, I've always tended to use prox effect in the manner you describe, as a way to give a greater sense of intimacy with a bigger, warmer sound. It often lends that intimacy without having to resort to (as much) follow-on compression/limiting. It also seems to encourage vocalists to greater moderation (which is sometimes but not always what one wants, of course).

 

An omni certainly gives a more accurate sonic image -- but it also tends to pick up a lot of room, to the extent one is in a reactive environment. (That is, few studios, home or otherwise, have truly dead/anechoic rooms.)

 

As a vocalist, I sometimes like to get up on the mic to increase the sense of intimacy (even as I then often roll off the bottom when I'm later fitting it into the mix... so I may be working, to some extent, against myself; still, I feel like proximity effect seems to have subtle effects beyond boosting the bottom). I often find myself so close that I have to sing across the path of the mic, even when using a pop screen.

 

I think part of me really wants to be Astrud Gilberto, circa 1964. Too bad I sound more like Bob Dylan, circa 1964.

[Jon Chappell]

As a vocalist, I sometimes like to get up on the mic to increase the sense of intimacy (even as I then often roll off the bottom when I'm later fitting it into the mix... so I may be working, to some extent, against myself; still, I feel like proximity effect seems to have subtle effects beyond boosting the bottom). I often find myself so close that I have to sing across the path of the mic, even when using a pop screen.

 

It's true that the closer you get to the mic, the more intimate the sound becomes, as the lip smacks, breath variations, and other mouth-generated artifacts will become more audible. Singing "across the path of the mic" is really really an off-axis approach that mitigates the proximity effect and distortion-causing plosives while retaining the intimate qualities you describe.

 

I wonder if there's a "depth of field" explanation, as there is in photography. With a camera, you have two ways to fill the frame with a given image: step back and zoom in, or step forward and zoom out. The effect is different even though the image is the same size. Singers up close on a mic will vary their delivery as a psychological reaction, but what's the physical explanation for two sounds at the same resultant volume, when one is back 12 inches from the mic and singing normally and the other is one inch away and singing mezzo-piano?

 

I always tell people that if they really want to hear good use of the proximity effect, they should listen to Bill Cosby's early comedy albums!

[Anderton]

I'm putting Bruce's post about proximity effect in the next issue of EQ. Great stuff.

[blue2blue]

I worked for a short time with a vocalist who gave great proximity effect... every time I stood near her, my pulse rate jumped and I broke out into a sweat.

 

 

I started shooting pictures before zoom lenses were affordable, so I have a pretty intuitive feel for wide angle vs telephoto issues. The underlying principles are, of course, quite different, but the effect can easily be thought of in parallel, as Jon notes. Using proximity effect can, indeed feel like the everything-is-equally-close collapsed sense of distance one gets from extreme telephoto.

 

And Jon's point about the off-axis effect (diminishing the bass-boost of prox effect) is one I'd long noted but that Bruce's explanation clearly illuminates.

[Mark L]

I'll give it a whirl

[MikeRivers]

I wonder if there's a "depth of field" explanation, as there is in photography. With a camera, you have two ways to fill the frame with a given image: step back and zoom in, or step forward and zoom out. The effect is different even though the image is the same size. Singers up close on a mic will vary their delivery as a psychological reaction, but what's the physical explanation for two sounds at the same resultant volume, when one is back 12 inches from the mic and singing normally and the other is one inch away and singing mezzo-piano?

That's an easy one, and Bruce pretty much explained it - The frequency response of a mic whose directional pattern is created by the phase difference between the front and rear of the diaphragm changes with the proximity of the source.

 

You won't believe how much difficulty I had finding a microphone frequency response graph on the web that showed proximity effect. I guess it was a bad thing back when the mics were designed. I stole these from Eddie Celitti's Tangible Technology web site:

 

 

 

Note that just a single curve is shown for the SM57, with a low frequency rolloff that (although they don't show it) makes it pretty flat on the bottom when you get close to it. The Beta 57 graph shows a family of curves at various distances. At 3 mm, there's about a 12 dB boost at 200 Hz. At 2 feet, the low frequency response is similar to that of the SM57. (most published mic frequency response curves come from the art department, not the engineering department)

 

Take two Aspirin and read this Shure technical note on how the proximity effect actually occurs, with vector diagrams and all.

[Bruce Swedien]

I love Proximity Effect! I use it all the tiime.....

It's like getting FREE EQ!!!

 

Bruce Swedien

[Jeff da Weasel]

I love Proximity Effect! I use it all the tiime..... It's like getting FREE EQ!!!

 

That's exactly what it's like.

 

As a live performer who's been doing it for far too long, I know by now exactly how to work the mic at live shows to get the most of proximity effect. I am unable to project higher volumes in my lower register, so I instinctively know by now that moving a couple inches closer to the mic when I hit those low notes will allow for a smoother listening experience for my audience. See "Fletcher-Munson Curve".

[WRGKMC]

I have a hard time singing without it. I rely on mic techniques to get my less than stellar vocals to come through.

 

As a brainstorming idea I've had, I always though it would be cool if the frequency responce and dynamic increase worked in reverse. If the db level dropped when you get close and intimate, it would eliminate the problems with overpowering the signal.

 

Coming up with a sencing device that uses light to trim the volume real time as you get closer to the mic to maintain DB level. I realize a condencer sort of does this by design, and compressors can be used to flaten dynamics, but to have a mic that can actually rides its own volume level based on the persons distance from the diaphram, would be just too cool. You could set min and max levels and avoid all kinds of issues. You could just as easily reverse the dynamics so the voice gets louder as you move away and softer as well.

 

To go a step further, you could probibly vary other tonal effects too. Add a plug to the mic, or have a special cord that will tie into an effects unit for live work. Have dry vocals eating the mic and echo, pitch bend, EQ, reverb etc as you back off. Maybe have it work in reverse or in stages. Chorus up close, then as you move back its slowly blends in reverb or echo. Hell of alot better than using a footpedal for vocal effects, plus if the gain is self managed, it would have to be a killer tool for singers and studios.

 

There would be a learning curve of course, and its not like you need to invent the technology though, just incorporate it into a mic design. As an intrum having a box that connects to an existing mic and varys the mics output could just as easily be used. Stick a velcro sensor to the mic or pop filter, or stand and you're good to go.

 

I'd experiment building something like this myself if I has the time, ambition, and cash to experiment to make a working prototype. I suppose someone will eventually come up with something like this eventually. Maybe even using therimin technology to vary the mics tone could be incorporates too so the singers hands have some influence on the effects.

[MDLMUSIC]

I really wish more "vocalists" (and I'm using the term loosely) would take the time to learn about stuff like this.

 

I've worked way too many open-mic type gigs where the vocalist must have learned his or her mic technique from watching Jerry Seinfeld. They hold the mic upright at the level of their breastbones and then wonder why the sound quality is so poor. I repeatedly have to tell them to hold the mic horizontally and sing directly into the ball end and they still don't get it.

 

The other big problem is the "singer" who can't figure out that they have some control over dynamics by how close or how far away their mouth is to the microphone.

 

It's like the old joke of the female vocalist testing the mic...

 

(Whispering directly into the mic) "Testing, testing..."

 

(Turns head to the side and yells at the top of her lungs) "IT'S NOT LOUD ENOUGH!"

 

(Whispers again into mic) "Testing, testing..."

[MikeRivers]

 

As a brainstorming idea I've had, I always though it would be cool if the frequency responce and dynamic increase worked in reverse. If the db level dropped when you get close and intimate, it would eliminate the problems with overpowering the signal.

 

Ever use a compressor? That's just what it does. When the input level goes up, it reduces the gain. It's because vocalists don't always keep the same distance from the mic (sometimes by choice, sometimes by gosh) that you often see a compressor in a vocal recording or PA chain.

compressors can be used to flaten dynamics, but to have a mic that can actually rides its own volume level based on the persons distance from the diaphram, would be just too cool.

 

Well, you could use one of the Neumann digital mics. They offer dynamics control right in the microphone, and it's the most transparent compressor you'll ever not hear. Of course it costs a lot of money.

 

There's a gadget that's an optically controlled on/off switch for a mic, sort of like those self-flushing urinals in public men's rooms. The idea there is to minimize leakage when the mic isn't being used and make sure that it's on when someone steps up to sing or play. But a continuous control? I dunno. Frankly, I think you're dreaming of a solution to a problem that nobody who has any business being in front of a microphone has.

[WRGKMC]

 

Ever use a compressor? That's just what it does. When the input level goes up, it reduces the gain. It's because vocalists don't always keep the same distance from the mic (sometimes by choice, sometimes by gosh) that you often see a compressor in a vocal recording or PA chain. I dunno. Frankly, I think you're dreaming of a solution to a problem that nobody who has any business being in front of a microphone has.

 

 

I wasnt looking to be patronized, I am quite aware of what a compressor is and have no problem using any current equipment. Hell I repaired the darn stuff stuff for 40 years, I'm quit aware of whats involved with current equipment and what it would take to develop the idea I suggested.

 

It is therefore not a pipe dream as far as being able to develop something that smoothly sences distance. A urinal on off switch as you suggested is the simplest form of burglar alarm sencing. I simply through I'd throw out a brainstorming idea I had kicking around for awhile and was seeing if anyone had some creative ideas to add on. Negative opinions are easy. It takes special talent to think of positive options.

 

If we all had the attitude that something can't be useful because it doesnt exist yet, or isnt a standard "everyone" uses, then there would be no improvements in audio equipment at all.

 

So, Have we truely lost the ability to look ahead and see if something can be useful or are we so entrenched in mediocrity that new ideas are taboo? I hope not. If we dont at least think of the possibilities, then we'd all still be recording on primative Edison cylinders, or maybe not at all.

 

I realise this has been harsh wording and I do applogize.

 

I will say the idea is based on a proxcimity effect of the original poster, not based on the signal passing into a mic and having its signal compressed, though that could easily be an option as would any effect we use now as being an option. Who says a singer only has to sing through a clean mic and let the sound guy or recording engineer make all the decisions. look at how many gadgets guitarists use to ge their sounds. If you're a pureist, then an acoustic guitar and mic should do. On the other hand theres a huge market out there for new technology. Look at that guitar player video game. It made millions. Was it playing an instrument? Hardly.

 

Compressing a signal through the strength of the signal itself is simply volume automation and since its attack and release times are set they gloss over many changes. For most stuff, Fine it works great and creates the same old thing. A comp is a whole different tool from what I was thinking about but a comp could surely be a triggered effect, only one of many though. You could have the comp kick in when the person is within an inch of the mic and gradually pan out like using an effects knob on a mixer as a person backs off. You could alre reverse it and make a dynamic mic act like a condencer when someone is more distant from the mic, its completely optional.

 

My initial thoughts were to change actual volume levels and have them work in reverse of how a natureal mic works as you get closer to it singing. This could preserve transiernts 100% but that is simply one aspect of what can be done. I've only listed a few options. Being able to trigger any effect based on mic distance and have the effects overlap, running in series or parallel could create any combination of changes as you get closer or more distant from a mic and a singers awareness of these changes ould be no different than a guitarist getting different shades for resonant feedback turning his instrument towards or away from the amp.

 

I wouldnt be surprised is something like that could also be used with these software amp simulators. Its the biggest thing lacking when you record direct. To say it isnt needed would be like saying guitar amps are needed. Half your rock musicians that use controlled feedback can tell you that its the #1 thing lacking recording direct.

 

If a proxcimity sensor can be usd to mimick how a speaker causes feedback, it could make money. It may require triggering a sustainer pickup being added to the instrument, but its a key element I've used forever in getting tones to happen playing. Turning, moving, sticking the headstock out all make differences. Why cant this be an option for a singer, especially a guitarst singer who has already developed this kind of controll?

 

Optical distance sencing in sequential smooth steps would be the key. Arm length would likely be the maximum distance. And to kill all sound, simply block the sensor, Turn off the switch, have a pad the singer steps on and only have it active in the distance of a foot or two from the mic, step off the pad and it shuts down, things like that so it doesnt go nust as someone walks by. (guitars cranked in a stand do that too if they arent attenuated)

[Lee Flier]

 

Do you ever find a preference of using an omni on a single voice to defeat proximity or reduce it? I've never done that myself but I notice others saying they sometimes like the overall effect of an omni on single point sources.

 

 

I'm not Bruce, and it'd be cool to hear his answer, but sometimes I do like to use an omni mic on a voice to give it more "air." Typically, I'll record lead vocals with a directional mic to get the nice fat proximity effect, but if there's a harmony vocal or a vocal double, I'll often record that with an omni mic. That way the parts complement each other nicely - if you record multiple voices with a directional mic, the cumulative proximity effect can make the overall sound muddy.

 

For a single lead vocal, I generally go with a directional mic because I think it sounds better and I usually like what the proximity effect does. So I only use an omni mic (or, sometimes, an EV RE20 which has very little proximity effect) if the vocalist needs to get up close on the mic but perhaps has a really bassy voice naturally, and the proximity effect doesn't sound good.

 

I'll add that usually, if you use an omni pattern on a lead vocal you have to put a baffle behind the mic, or the singer has to be in a vocal booth, because otherwise you usually get too much of the room in the mic. So, again, a directional pattern is usually the way to go on a lead vocal. Sometimes I'll even use figure 8 if I want the proximity effect but still want to catch some of the room.

[MikeRivers]

I wasnt looking to be patronized,

I'm sorry. I didn't get a chance to read your CV. Ummm. . . where is it anyway? You're proposing a complicated solution to a simple problem that already has a perfectly good solution. But go ahead and dream. Maybe you'll hit the jackpot with your idea.

It is therefore not a pipe dream as far as being able to develop something that smoothly sences distance.

That's not at all hard to do. But what are you going to do with that information? You're going to reduce the gain of the system so that it doesn't get louder when someone gets closer to the mic. That's exactly what a compressor does. Now I understand, and I trust that you do, too, that not all compressors work the same. So you may come up with a different transfer function with your distance sensor that works differently than any compressor.

 

The problem, though, isn't that someone is closer to the mic. The singer, presumably, is doing that consciously, to take advantage of the proximity effect. The problem is that the inverse square law works. He gets closer, the SPL at the mic is greater, and therefore the voltage out of the mic is higher. And the average voltage across the spectrum is even higher than the inverse square law predicts because there's an added low frequency boost.

 

But suppose the singer realizes that he gets louder as he gets closer to the mic (hey, if Jeff can figure that out, anybody can ) and he compensates for it by singing softer. Your distance sensor doesn't know that. But a compressor will, because it acts on the voltage coming out of the microphone.

Negative opinions are easy. It takes special talent to think of positive options.

Negative opinions get you thinking about your idea from a different direction.

If we all had the attitude that something can't be useful because it doesnt exist yet, or isnt a standard "everyone" uses, then there would be no improvements in audio equipment at all.

That's not the point. You described a problem and I told you what seems to be a reasonable solution. What's wrong with a compressor? Is it just "not invented here?"

Who says a singer only has to sing through a clean mic and let the sound guy or recording engineer make all the decisions. look at how many gadgets guitarists use to ge their sounds.

There are some creative singers who use effects in performance that have been adapted from the studio processes. Nothing new here.

If you're a pureist, then an acoustic guitar and mic should do. On the other hand theres a huge market out there for new technology. Look at that guitar player video game. It made millions. Was it playing an instrument? Hardly.

I'll admit that the game market is huge. But I thought we were talking about audio here. People are hungry for new effects in the audio biz too, for sure. If you had invented AutoTune, you would have made millions too. But I don't know that the company who makes that proximity-operated mic muting switch has sold more than a few hundred. That's the way the market for new audio gadgets is. But you could be lucky.

Are you aiming to emulate the effect of an engineer's finger on a fader, riding the level to keep it even in the mix? That's the goal of compression, and when it's right, it works well. Personally, I don't think it's a 100% replacement for a finger on a fader (though some do).

You could have the comp kick in when the person is within an inch of the mic and gradually pan out like using an effects knob on a mixer as a person backs off.

That's essentially what the threshold control on a compressor does. It sets the level at which the compressor starts working.

Compressing a signal through the strength of the signal itself is simply volume automation and since its attack and release times are set they gloss over many changes. For most stuff, Fine it works great and creates the same old thing. A comp is a whole different tool from what I was thinking about but a comp could surely be a triggered effect, only one of many though.

You could alre reverse it and make a dynamic mic act like a condencer when someone is more distant from the mic, its completely optional.

Huh????? How is a dynamic mic different from a condenser, with respect to distance?

Being able to trigger any effect based on mic distance and have the effects overlap, running in series or parallel could create any combination of changes as you get closer or more distant from a mic and a singers awareness of these changes ould be no different than a guitarist getting different shades for resonant feedback turning his instrument towards or away from the amp.

So what you're proposing is using distance from the mic as a control for some parameter? Well, maybe you can sell that, but I'd try something more interesting than volume first.

 

Think your ideas through and consider the process and the results. That's what makes good products.

[blue2blue]

That's exactly what it's like. As a live performer who's been doing it for far too long, I know by now exactly how to work the mic at live shows to get the most of proximity effect. I am unable to project higher volumes in my lower register, so I instinctively know by now that moving a couple inches closer to the mic when I hit those low notes will allow for a smoother listening experience for my audience. See "Fletcher-Munson Curve".

Fletcher-Munson is relevant to the general discussion, but I fear some of the less technically oriented visitors or lurkers (none of you regulars ) might get the mistaken notion that it's somehow directly related to proximity effect; in reality, it's SPL reaching the ear that is the primary factor in the so called Fletcher-Munson effect. Of course, proximity can affect SPL --obviously, since radiative sound, as a general principle, decreases in relation to the square of the distance from the radiative sound source and a closer source means higher volume. Those looking for how prox effect works should reread Bruce's explanation or follow the link that Mike posted.

 

(I'm starting my own local chapter of Overexplainer's Anonymous, by the way.)

[temnov]

Very cool thread! Great explanations.

 

The simple way of explaining the complex processes

 

Thank you.

[elsongs]

[WRGKMC]

 

I'm sorry. I didn't get a chance to read your CV. Ummm. . . where is it anyway? You're proposing a complicated solution to a simple problem that already has a perfectly good solution....... That's not at all hard to do. But what are you going to do with that information? You're going to reduce the gain of the system so that it doesn't get louder when someone gets closer to the mic. That's exactly what a compressor does.

 

 

I understand all the points you made, believe me. My idea is to have a programmable tool that a singer would use in a creative fashion that adds control over any parameter you want based on distance sensing.

 

Volume control may be only one of parameter that can be controlled.

 

Now why would I suggest it, if things work fine as they are?

 

Because it hasnt been done as far as I can see.

 

It would be useless to many singers who have no technical abilities to use distance as a triggering tool. For others who are pro singers and have the whole proximity and using the mic distance thing down, it could open up all new doors. They wouldn

[Bruce Swedien]

 

Hey Bruce, Do you ever find a preference of using an omni on a single voice to defeat proximity or reduce it? I've never done that myself but I notice others saying they sometimes like the overall effect of an omni on single point sources.

 

 

 

 

I would never use an omni mike to defeat Proximity Effect simply because I absolutely LOVE proximity effect and what it does to fatten up a lead vocal...

 

Bruce Swedien

[Ronan Murphy]

 

Tay is awesome. We have actually worked together.

[philbo]

It's a great effect... but I wish it was illegal for radio DJs - - I get tired of deciphering muddy commentary buried in bass wash...

[Lee Flier]

It's a great effect... but I wish it was illegal for radio DJs - - I get tired of deciphering muddy commentary buried in bass wash...

 

Are they not using RE20s anymore?

[Hard Truth]

1. I'm interested in thoughts from Bruce or others re. proximity effect with horns. It seems to me that many good horn players work the mic as a good singer would. For that reason I think it is unfortunate when a horn player uses a mic attached to their horn, as many do when playing live.

 

Also singers who wear head mounted mics are missing an opportunity for greater expressiveness.

 

2. I assume you would not have an opera singer or other singer intentionally sticking to a pre-microphone style/technique close enough to the mic for proximity effect to kick in. Right? Would you select a mic with more low end to make up for the lack of proximity effect?