About microphones
> From: Steven Fisher [mailto:sfixxer@axxxxxve.cxm] > Sent: Wednesday, November 17, 2004 3:00 PM > To: podcasters@yahoogroups.com > Subject: [podcasters] Looking for a quality microphone > > Can anyone out there recommend a microphone for doing podcasts? > > I don't want to use the cheap PC microphone nor the headset mikes. > > I was looking at a bunch at my music store but don't really know. > > Looking to spend no more than $150.
I've been looking at podcasting recently, as a way to publish my Victor Xray material and related research for the Clan Analogue label (I had to take the older Nerve Agent stuff off line because of extensive and server-swamping file leeching from China-based IP addresses).
Anyway, I subscribed to the podcasters yahoogroup, because I was interested in learning about the tools I could use for podcasting (specifically the server and client tools). The blog I use, Pebble, will most likely support RSS 'enclosures' (the heart of podcasting) in the next version 1.6.1. In the meantime there's some research to be done. Anyway It struck me the number of questions people ask on the list, not about the actually blogging/podcasting tools but about the basic processes of recording and editing audio. My anecdotal research suggested the topic of microphones comes up quite frequently, I guess I decided to share my experience with microphones and similar material by posting an introductory primer about microphones to the list.
In order to share this text a bit wider and archive it for the web, I present here my microphone primer, aimed primarily for the person looking to get into podcasting but otherwise generally useful. I'm going to address this from the point of view of someone who wants 'quality on a budget'.
About microphones
There are several different types of microphones, but roughly speaking there are two main types of microphone in use today; 'Dynamic' and 'Condenser' (I will discount 'Ribbon' microphones here as they are fairly specialised and very delicate, as well as some other more esoteric types).
A Dynamic microphone has a diaphram attached to a small piece of coiled wire which moves when air hits the diaphram, the coil moves through a magnetic field supplied by a magnet, inducing electrical current into the coil. This current is the signalyou get at the output of the mic. A Condenser microphone uses a different principle. It uses a capacitor (Condenser is an older term for capacitor) not a coil. The pressure changes on the diaphram causes the distance between the plates of a capacitor to vary, and thereby, the capacitance to change. However a Condenser mic usually requires a power source as the capacitor must be charged by an external source. Sometimes this is supplied by a battery, sometimes by an external power source supplied down the microphone cable called 'phantom power' (why the power is phantom is not important here).
Here is a simple explanation I found on a music retailer's website: http://www.sweetwater.com/microphones/mic_types.php and another I found on a site for consumer video recordists - http://www.camcorderinfo.com/content/picking_a_microphone.htm.
Another consideration with microphones is the pickup pattern of the microphone. The pattern of the microphone is how well the microphone responds to sounds coming from different directions. There are three basic types. There are 'omnidirectional' microphones, which pick up sounds equally from all directions. There are 'figure of eight' patterns which pick up sounds from ahead and behind but not from the sides, and lastly, there are cardioid (car-dee-oid) microphones which pick up mainly from the front of the microphone's axis. You will want a cardioid microphone. For general applications, avoid hypercardiod or shotgun types because these have significant rear lobes and severely narrow pick up patterns. Some microphones (typically the more expensive Condensers) have switches to change to pick up pattern from omni to figure-8 to cardioid.
OK enough with the theory. What sort of mic should you buy? You will be able to buy a cardioidmicrophone of either a Condenser or dynamic pickup type of reasonable or better quality for $150 USD, so what is the reason for buying it? I will list the primary advantages and disadvantages of each type.
Dynamics are very rugged. They are also usually although not always cheaper. They require no external power source. Typically they are used in live performance situations, on stage, in the field for news gathering, on really loud sound sources (close-miking of drums), places where they might get hit or abused (close miking of drums), basically wherever 'ruggedness' or 'lack of power supply' is the primary reason for selecting them. They suffer from a lack of sensitivity (for example you would not use one to distance-mike a solo singer at the other end of a cathedral space). They are often larger and heavier. They have a slower response time, which means they don't pick up high frequencies so easily (not so important for recording voice, but possibly a consideration in other applications).
Condensers are sensitive, and have much better audio quality. They also have higher levels of internal noise, they are fragile (generally they wouldn't leave the studio), they are often more expensive (the most expensive microphones are Condensers). They also require a power source.
Generally however, and speaking personally, I would definitely recommend anyone who wants a good quality microphone for recording spoken voice podcasts buy a condensor. Go to a music store, not a computer store. The important point to remember here is that every microphone that attaches directly to your computer mic input will be a dynamic unless it also has a battery in it.
The other really, really, important thing to remember is that generally, computer hardware companies know jack-all about making specialised transducers like microphones and speakers. There is a funny thing in audio equipment manufacture - companies that make quality transducers tend to make nothing else. In my studio you will find brands shared on several different devices from guitars to synthesisers to effects, to mixing boards, and all points in between but my speakers and microphones are made by companies that tend to make (respectively) only speakers and microphones. This counts *especially* for microphones.
Condenser microphones in recent years have seen a flood of budget models on the market. This is due to cheaper manufacturing of western designs being available by manufacturing in locations like China. Although these budget models don't quite match the quality of the multi-thousand dollar microphones, nonetheless they are still very good quality for the average home user want to record some voice for a podcast or other similar purpose. I use a budget Condenser and I am quite happy with its results for musical applications.
Unfortunately the downside to using a Condenser microphone is that you will also most likey have to purchase a mixing desk that supplies the mic with phantom power. Phantom power requires the microphone cable to be the three-wire 'balanced' cable with a three-pronged 'XLR' connector at both ends. Some mid-range computer audio interfaces come with balanced inputs with phantom power for microphones, so if you go for the better audio interface with a propermicrophone input you might find your recording quality increases generally for only a small additionally expenditure. The M-Audio Mobile Pre, which is a USB audio interface, for example retails for about $150. I also found an 'education package' that included this interface and two condenser microphones for $299 including some music software as well although this price might only be available to teachers and students of educational establishments.
The upside to all this is you will have a much more flexible recording situation than before. A small four or six input channel budget mixing desk from a manufacturer like Behringer will cost almost next to nothing. Mackie also have better quality but more expensive models. With a couple of mics and say, a cd player or other sound input source you will be easily able to produce a quality sounding interview in your spare room with only a little practice.
The sort of budget I am talking about here is, in US Dollars:
Condenser microphone: 2 x Samson C03 (switchable pattern) $100 ea
Mixing desk with phantom power: Yamaha MG10/2 $100.00
Cables for mics 2 x 10': $30
Cable to connect mixer to pc: $5
Mic stands (boom type) x 2: $50Total: $385 (about $250 for only one mic with mixer, stand and cables).
Under $500 including two pairs of quality headphones.
Bear in mind I am not choosing the cheapest option in each category - I'm just picking what I'd buy for this based on what prices I found for what equipment at online retailers. The list prices of most of this gear is much more than I write above, but these are prices I easily found by googling around. Model selection is not indicative of suggestion - for example one place I found (Sweetwater above) had over 20 capacitor microphones at sub-$100 prices, although some where lapel mics 'without termination' made for use in more expensive radio microphone rigs. I also found a $60 mixer with phantom power which would do for recording a voice-only podcast, quality depending.
When buying mics I'd also advise to go to a store where you can try them out first. Tell the salesman what you want it for. Take your own pair of headphones with you so you know what you are listening to. If you buy a package as above (mics, mixer etc), see what the guy will throw in the deal, cables or stands - although bear in mind, you're shopping at the very low budget end of the spectrum already.
Anyway, I hope that anyone looking at buying a new microphone can use this information helpfully.
scot mcphee.
-- Autonomous Organisation http://www.autonomous.org/