Use Microphone with Macbook Pro?

what kind of mic? perhaps it needs phantom power.

which AT mic model?

it's always better to have an amplifier, or at least a USB-XLR adapter: I doubt you'll get a decent sound quality from this setting.

ok, so it´s a dynamic mic, so it doesn't need 48v phantom power. Are you usng standard cables, or did you made them yourself? (perhaps it's a wiring issue).

What recording software are you using?

Try setting the input audio level to max (in the preference pane), and try also to max the input in your DAW (garageband?)... there you can see the real input level and adjust it.

Either way, if you're going to record podcasts fairly often, I'd suggest buy a USB audio interface with XLR inputs and monitoring - you can get one for as low as $50, or a USB-XLR adapter for around $30. That'd give you better audio quality and control over your recordings.

Hope this helped.

One final question: is the rec level higher when you select the internal MBP mic instead of the line in? I'm just puzzled by the fact that you have to yell to the mic to get anything in... if so (the internal>line), then maybe there's something wrong with your AT mic or the line in connector. Try plugging it into a mixer with another cable and see what happens. Also, if you're using XLR -> 1/4 -> 1/8 adapters, another thing that might be the problem is using different TRS (1/8 & 1/4) connectors. Be sure that both adapters have the same number of black rings in both. The most common problem with mics usually come from the wiring and cables.

Right: the 1/8 or 1/4 inputs do not provide phantom power. 48v ph-pwr is only needed in condenser microphones (though XLR cables), and it's given to the mic through some USB, Firewire interfaces, a ph-pwr dedicated source, a mixer or an amplifier. But this particular mic you have doesn't require it since it's a dynamic mic.

Quick note: as for the USB interface, it depends on how much you'd like to spend/invest and the uses you're planning for: you get what you pay for in terms of sound quality. Just remember the mic is the first link of the recording chain, so the better sound you get from it, more things you can do with it while editing. If you're only recording spoken word (podcasts/voice-overs) I'd also take a look at some USB mics (this one works great). If you do buy a second (or USB) mic, I'd recommend to stick with a dynamic since they are better with voice, rejecting noise and are less demanding in terms of microphone technique. Condenser mics are great, but most are way too sensitive.

USB interfaces: this is a simple one for a fair price. This other one has had good reviews for simple uses, and provides direct monitoring.

As for simple adapters, this USB-XLR adapter cable seems ok, but I've had no experience with those.

These are some affordable solutions. If you later get deeper into digital audio, there are plenty of prosumer interfaces. This one works great with mac and offers plenty of flexibility (Firewire is best suited for audio interfaces). This one (digital output) is great for voice-overs, but more on the pro side. Any pro/prosumer solution will demand a matching microphone, so the investment gets quite high.

Hope this helped. Cheers!