Micing. Article Version 0.1g 27th May 05 Update

So what's this article about?

Well if you haven't read the title, well I'd be wondering what you're looking for. Basically the whole issue of micing is a very wide issue depending on what it is that you're planning to record, obviously depending on the application you'll need to consider different things. In the case of this article I'll just be talking about issues that deal with recording solo mono vocals with a pc without a mixing deck.

Article Index


Issues that'll mar your recordings

Cable Rattling

If you've not been blessed with a microphone stand you're liable to have this problem, particularly if you're working with a reasonably cheap cardiode vocal microphone. The obvious way to limit this noise is by not moving a muscle, which is almost impossible. What I would suggest is you try using some kind of shield over the lower parts of the microphone towards the base. I've found that light materials like very wafer thin tissue paper can be of reasonable use if secured to the mic barrel properly. NOTE: If you get too clever with this wrap-everything-up-method, you might find your recorded signal distorted and volume levels to record requiring more adjustment than without the 'guard' in place.

Cable Noise

I find that with cheaper cardiode mics with high impedance ~500ohms or more that there really is an issue with cable noise just using them. Not much you can do about this kind of noise, but you need to think about ways of minimising external interference. PC's tend to be very noisy things and old powerboards, power leads as well as other leads can and do add to the noise you experience in your recordings. So if your microphone has a long cord you tend to find that the best way to get the least extra noise from electrical sources is to make the straightest path away from your computer that goes as far away from all cables and the pc itself. The further you are away from magnetic fields the better. Additionally it's obvious to say that things like CPU and PSU Power supplies make a fair bit of unwanted noise/electromagnetic disturbance so being further away from those is also of great benefit, particularly if you're running an old system and the bearings in your fan are creaking/need cleaning(sleeve bearings) or you're running a new AMD Athlon/Athlon XP or greater and have the extra cooling fans you need. Not twisting your cables around and tying knots in them also tends to help.

Jacks

Not talking about a guy's place here, but more about the plugs you plug into your soundcard or breakout box or mixer etc. Generally it pays to have good leads not to mention good pin converters if you need a pin adapter to go from 1/4" or RCA to standard headphone sized plugs. Generally typified by being stereo and gold.

Page Turnings

Just don't speak and turn pages or waft paper. Get the picture?

Desks and Vibrating Surfaces

Even if you have a microphone stand I really don't think it's a good idea to go balancing your mic or the stand on a desk with a pc or electrical equipment. Particularly in the event of using a pc you tend to find you will pick up levels of vibration that you really wont like later.

How close should I be?

That's a very good question. When going to record something for some of my tinkerings I find that it varies depending on how you have the microphone setup and whether you're looking for more lead type vocals or whether you're looking to make a lot of noise or be a bit distant. Generally to pick up on the good quality kind of crisp sound a cheap cardiode mic can make you need to be reasonably close. That means about two to five centimeters away (some mics will pick up lower frequencies much much clearer at close range, however you do need to watch for the bassyness of some mics at this range). Or going by the old school of thought 5-6 inches being a bit to far away if you're trying to get some crispiness out of your mic when using your larynx.

Direction!

Now this is another issue. Whether or not you directly speak into the top of your microphone at zero degrees. The answer is probably no because if you face it directly you tend to increase the amount of unwanted breathing type sound into the mic. So slightly to the side of the center is probably a better idea.

Tip: Many cheap microphones come with a lack of directions concerning best usage. A number of chinese manufactured microphones come with a brand sticker, in some cases this is indicative of the direction they should be set up e.g. the sticker should face the user.

Recording Environment

Obviously if you're recording inside a closet it's pretty obvious that you're recording will take on the acoustics of the closet. Generally with vocals you don't particularly want to sound like you're in a room or in a cave so it's best to try and minimise the effect of the room, most likely achieved by recording elsewhere or being game enough to use extra reverb or environmental fx on your finished product. Things like heat can be a bit of a bother when micing as some equipment really doesn't take to sounding terribly good when there's a lot of moisture in the air and there's not much you can do about it really (except move somewhere cooler like the South Pole).

Micing for consistency

The best way to record vocals reasonably consistently is to a) have a microphone stand b) a way of marking your spot. By marking your spot I mean a way of being able to remove yourself from the current mic setup and then return to it exactly by some kind of marker (could be an X marks the spot). Obviously if you don't have a microphone stand this makes things a bit difficult as you have to rely on keeping your arm in the right position throughout the entirety of the recording. Balancing your mic on something so that the barrel is free in 360degrees XY by 180 degrees to the horizontal as well as 180+degrees towards you (Z) is probably the best way to do things if you don't have a proper stand. Do remember not to let the things drop though. Crack the carbon lattice and it's game over pretty much.

Pop Goes the Weasel

If you're not careful how you record you'll find that certain letters you speak/sing/yodel will come out with a pop like sound or be particularly sibulant/plosivey. You can however counter some of this by either re-recording and trying to emphasis the letters differently/fix it in software or by constructing some kind of screen, typically made out of coat hangar wire and pantyhose. Very likely to need a microphone stand if you're doing the latter. Some microphones (generally good ones) may have proper "caps" that can be bought to go over them to minimise these issues, generally you can also buy generic ones, however results may vary as well as cost.

Recording volume

Now this is a tricky one. I can't say I'm perfect at it but I can say that the concept of recording everything as loud as is possible is a little misguided. I tend to find if you know reasonably what you want your vocals to sound like you have a starting point in trying to adjust the recording volume accordingly. I generally try for a reasonably loud 'softspot' when I work with mics, the point where I hear particular bright harmonics before everything just starts seeming 'warm' and overly loud. I know that's pretty vague but that is reasonably how I do it. It's best to do a couple of takes and then figure out whether you're in the ballpark or not. While testing it's very important to look at the levels you're achieving when you're talking/acting/singing into the mic as you need to have a good idea about how much headroom you have in the digital domain(that is how close a waveform gets to 0db/the maximum peak of a waveform that one can record, one might liken it to being able to only draw a line so far vertically on a piece of paper before one hits the edge) as digital clipping is very nasty and very difficult to repair when it really becomes an issue. Particularly when using a reasonablish mic with a good dynamic range you'll find that the peaks may go all over the place very easily so it really is best to examine things first before committing yourself to recording large chunks of a program. Recording to softly in an environment where your equipment has a rather bad sound to noise ratio is also not very recommended. Then again using equipment with a lousy sound to noise ratio is also not very recommended ;)

If you're going to record a scream I suggest completing everything else you want to first and checking your recordings and then altering the volume levels as required to record the scream.

I'd also advise that with certain types of cardiode you may start sounding very bassy if you get way to close (an example of this may be say if you're using a Shure SM57 for recording vocals (not intended to be a vocal microphone), it doesn't have the shielding of the SM58 although it apparently has the same construction otherwise) so you need to decide whether it's to bassy when you record and move away or figure out how to treat it digitally.

Examples of things going wrong

Examples of things going wrong

waveform A without clipping

This is waveform A. Notice that on average it sits between plus 6db - -6db

waveform B with clipping

This is waveform B.

Exactly the same source input as waveform A, but the peaks average 200% higher (6db), thereby truncating the waveform when it hits or exceeds 0 (where the waveform peak goes past the edges of the above waveform B image). This results in what is known as "clipping" (marked in the grey shades near the extreme peaks). The recorded sound now sounds harsh when the excessive peaks are played back and the nice peaks seen in waveform A are not presented as they have been "truncated" or "discarded". Once this has happened it is almost impossible to replicate or replace the missing information so that it looks like waveform A which has all the signal data intact without clipping. The solution to this problem is to rerecord such that "clipping" doesn't occur, that is record your vocals/input such that the top of the peaks of the waveforms do not exceed the recordable boundary of 0db.

Well that's it from me on Microphones for the moment. So I hope somebody learns something from all this. Need someone to scream at over the generalizations in this article? Find us here.



Once In A BlueMoon Technical is part of Once In A BlueMoon Productions. If you arrived here by any other means, please click here to make sure your receiving the most uptodate link and information available. This guide is © Owen Spratley 2002-2005, and shall not be reproduced in part/whole without prior permission.