Quiet Microphone

Some detail here would help tremendously. What Mic do you have? What kind of Mac do you have? (go to the Apple menu>About this Mac>more info.... What is the model name and Model number? Select hardware pick in left window). Which port did you plug your mic into? Did you go to your control panel, select the input port and set the input attenuation?

Requirements: electret (condenser) mic plugged into a mic jack that can supply bias to the mic and amplification for the produced mic signal. Properly configured path from input jack to audio circuitry on Mac board. Go to system prefs > sound. Push input button. Select internal mic/line in. Set levels.

Put as much of the system info as you can put into your forum profile. It helps to troubleshoot your Mac and get you fast answers to problems.

The alternative to using an external pre-amp with your existing microphone is to use the Apple "PlainTalk" microphone that shipped with the G4 (PCI Graphics) models. The tip of the microphone's extra-long 3.5 mm plug receives the power for its built-in pre-amp, which boosts the microphone's output to line level. This design prevents a standard length 3.5 mm plug from contacting the power pin in the jack. The third-party microphone that you're using undoubtedly outputs a mic level signal, which is lower than a line level signal. The PlainTalk microphones can be found at eBay, like this one.

Jeff brought up a good point. It may be that you not only need a pre amp, but the plug going to the mac needs to mate with the jack's contact for both power and a path to the audio. Apple over the years has done all kinds of weird things to their audio. In this area they never heard of the KISS principle. On one of my Macs I ended up buying the iMic from Griffin which gave me easy connection to the audio through the USB port. I'm sorry I can't give you more help at this point.

The technical term for this is reciprocity. However, if the volume is higher, what this shows is a need for a preamp. You probably have an electret mic alone with no other amplification. Apparently, Apple's mic used amplification and the main board didn't amplify very much.

P.S. another secret: a speaker is a linear motor.

My iMic works great and the company is very good to deal with. Best of luck.