What are you planning to use to input your microphone signal into the Mac?
Condensor mikes: Large diaphragm condensor mics are used predominantly for recording vocals because the design tends to flatter voices: smooth bass and articulate highs. They are available in wide variety, each with particular features and "sound colour". Small diaphragm condensors are mostly used as instrument mics where accuracy, esp. in the high end, is desired.
Note: For accuracy sake, the cheap and nasty mics that come with cassette recorders and answering machines are electret condensors, so when we talk about condensor mics in the musical sense, we're referring to a small or large diaphragm condensor, not an electret condensor.
Condensor mics require power to charge the capacitative plates of the transducer. This power is sometimes provided by a battery, occasionally by a dedicated power pack specific to the mic, or more often by "phantom power", which is nominally 48V (but can be as low as 9V) that is provided by the preamplifier to the mic "up" the microphone cable.
This is a problem for Mac recording, because no Mac provides phantom power (or a 3-pin XLR jack). Neither do the least expensive microphone interfaces like the iMic.
You would be looking at a Firewire or USB audio interface from Edirol, M-Audio or Presonus (to name some popular brands) that had both a preamplifier and phantom power. These type of interfaces with two to 4 mic inputs will run $150 - $600 (more elaborate ones will go up to $2500)
Alternatively, you could get an inexpensive mixer (Behringer, Alesis, Tapco/Mackie) which provides mic preamps and phantom power, and just run a line level signal to the Mac or a Griffin iMic.
Large diaphragm condensor mics of acceptable quality have come down dramatically in price, due to mass production in China. The microphone you can get for $90-$120 today blows away an "entry level" $400 mic from 10 years ago. Brands to look for are Behringer, Studio Projects, Marshall/MXL, Red, and many others who rebrand these Chinese mics.
Rode, the Australian mic manufacturer, started out selling mics made in China to their designs, but several years ago switched back to producing in-house. So what you get if you are buying used depends on how old the mic is. There are many models and revisions of Rode mics, so don't be taken in by sellers claiming to sell a $800 mic for $400. Some comparable to Rode in this mid-price level are Studio Electronics (SE), Blue (innovative mics from Latvia) and Audio Technica (their 30xx series and the lower end of their 40xx series).
As opposed to handheld "performance" mics, large diaphragm condensors are almost always mounted on a stand, with a shock-absorbing mount and a shield or pop-filter in between them and the performer's lips.
I should mention that there are some other mics in the market: Ribbon mics use a differnent technology, and can also be very nice on voice and instruments. They have also come down some in price (but not as far) and they do tend to be more fragile - prone to being dam,aged by blasts of wind or too-high sound levels. Royer and AEA are two manufacturers.
Dynamic mics are mostly used in performance, and for high impact sound sources like drums and guitar amps. Shure, Beyer, Electo-Voice, Peavey, Sennheiser, Adio-Technica and AKG are some makers. Not all handheld mics are dynamics though - there are some condensors and even one or two ribbon mics made for performance use.
I recommend that you study up on some of the basics with books and magazines before making a decision. Hit the library. Good magazines to read are: Sound on Sound, Recording (the current issue is all on mics), Electronic Musician, Keyboard, Future Music, Computer Music, Mix. They often have articles on how to record acouostic instruments, and microphone selection.
Thanks
Trevor
CanadaRAM.com
