Please excuse the title, but I didn't know what else to call it. I just thought that I'd share with you and the rest of the online community how I fixed my problem with the microphone issue with the Mac mini. I realize it's been two years since anyone has posted anything in this forum on this particular topic, but allow me to share my input.
Going from other tips I had attained from this article, I came to the realization that, like everything else with Macs, many of their ports are "passive" ports and not what I'd call 'fully' operational. What I mean by that is, I've seen devices in the past that would not work when connected to the Mac, in certain places or instances.
For example, Apple's keyboard has two USB ports when one can utilize the keyboard as an additonal 2-port hub for additional USB devices. But, I found out that these ports in the keyboard aren't energized by themselves. The keyboard takes the power of one port and switches it into two ports AND powers the keyboard. In essence, USB devices that need a higher power current in order to work, will give you a "USB low power notice" from Mac OS X.
The same thing can be said about the addition of a firewire hub, and in THIS specific case; the MICROPHONE port. For some odd reason, one needs to connect a self-powered microphone to the Mac in order for it to work. Here's what I did:
I had a personal tape recorder from when I was a kid (about 20 years ago.) It's the kind that kids like to use to record their voices onto a cassette tape. I pondered the thought that since this tape recorder uses its own power supply, maybe I could use a headphone extension cable, couple into the back of the Mac mini on one end, and the other end plug into the port of the tape recorder marked "monitor." This is why it made sense to me that the iMic device worked. It's powered by USB, and uses the USB power to amplify the power to the microphone, causing the microphone to work, like it's supposed to in the first place.
It seemed so ridiculous, but I was getting desperate to utilize the ability to have a microphone with my Mac mini. It turns out: IT ACTUALLY WORKS!!!!!!!!!!!!!!!!!!!!! I'm not kidding. Here's what one must do for this silly method to work:
1. Find a tape recorder that has a built-in microphone, or attach a microphone to the tape recorder's microphone port.
2. Use a (male-male) headphone extension cable to connect the tape recorder and the Mac mini together. One end goes into the back of the Mac mini's microphone port, the other end goes into the port of the tape recorder marked "monitor". (not "Mic"; that's for an external microphone to attach to the tape recorder, only.)
3. Make sure the tape recorder is plugged in or has batteries to power it, independently.
4. If you're ready to start talking, set the tape recorder to "RECORD" by pressing the "RECORD" button.
Note: Some tape recorders won't allow you to press the "RECORD" button unless there's a blank cassette in the deck. You can bypass this by looking for the dip switch inside the recorder's door, pressing it down with your finger and THEN hitting "RECORD" to bypass the need to have a tape in its deck. Or, tape the dip switch down, use an empty cassette with all its film removed that still has the recording tab still set in the cassette.
5. Talk/sing/or otherwise make noise into the microphone of the TAPE RECORDER. I did this today via a long conversation with my best friend. He assures me that the reception sounded great. I called myself and left a voice mail on my cell phone using Skype, just to make sure. When I listened to myself, I was udderly surprised how great I sounded. Who'd have thought, eh?
The thing that's nice about this is, you can also use this method to input music/sounds from pre-recorded cassette tapes into your Mac. I used a program called "CD Spin Doctor." I put a tape into the tape deck, pressed "PLAY", set the PROGRAM CD Spin Doctor to "Record" and got a high-quality recording onto the computer. I'm so happy, because I didn't have to spend a dime an expensive iMic or another solution that might have been more. I hope this helps people from now on on the Internet.