"Audio In" Port-How do I use it?

Discussion in 'Mac Basics and Help' started by thestubbornrock, May 28, 2006.

  1. thestubbornrock macrumors newbie

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    May 28, 2006
    #1
    How do I use the "Audio In" port with an external microphone?


    I've tried plugging in a couple of different microphones and none of them work. I'm using a 12" PowerBook G4.

    Attached is a photo.
     

    Attached Files:

  2. trainguy77 macrumors 68040

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    Nov 13, 2003
    #2
    Audio in is not a mic in. Its line level in. So it will not provide the power needed to run a mic. This input works when you plug something that has its own power source into it. (not "powered" these are for speakers) You want line level going in there.
     
  3. frankblundt macrumors 65816

    frankblundt

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    #3
    Which means you need to either just use the built-in mic (i presume it has one), or a usb mic or headset, or something like the Griffin iMic to plug your mic into.
     
  4. Flowbee macrumors 68030

    Flowbee

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  5. dogbone macrumors 68020

    dogbone

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    #5
    Ah I see, this is the answer to a thread I posted yesterday.

    That explains why plugging some headphones with a build in mic didn't disconnect the internal microphone.

    So what are those headphones with a stick mic attached used for?
     
  6. frankblundt macrumors 65816

    frankblundt

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    #6
    PCs with mic and speaker jack points (like macs used to have). Now you're better off getting a USB or bluetooth version.
     
  7. trainguy77 macrumors 68040

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    #7
    Yeah, the cable has 2 connections instead of one.
     
  8. dogbone macrumors 68020

    dogbone

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    #8
    I can't believe I was using one of these headsets with a stick mic plugged in. I tried using my normal headphones with Skype last week and noticed that it seemed to work as well as the headphones with the stick mic plugged in. Now I know why. Doh.

    What sort of things get plugged into the audio in port? Would that be a drum machine for example?
     
  9. trainguy77 macrumors 68040

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    #9
    Yes some drum machines would be able to use the line in. But most I would think would be firewire or USB. But for example you could connect your stereo amp to it using a RCA to 1/8 inch. You could also connect anything that has a headphones out. So your diskman, walkman and that type of thing.
     
  10. dogbone macrumors 68020

    dogbone

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    #10
    Is the Griffin iMic a mic or is it just an interface for a mic?
     
  11. frankblundt macrumors 65816

    frankblundt

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    #11
    just an interface for a mic (and any line-in, like from an amp) as well as an audio out. Supposedly slightly better quality (better shielded) than using the internal jacks.
     
  12. MustardMan macrumors member

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    Apr 26, 2005
    #12
    To clarify a few points here...

    1. It has nothing to do with the mic needing power, as insinuated by trainguy. The voltage level coming out of a mic is lower than that in a line level signal. The impedence is also different as well. That means a line level jack is expecting certain electrical characteristics and a mic gives different ones which won't work (usually) with a line level input.

    Some mics DO require power (ie a condenser mic that takes phantom power) but these are generally high quality and wouldn't connect using a mini jack. The most common connection type for something like this would be a three-pin balanced XLR.

    2. The input on the mac is line level. A line level output is NOT the same as a headphone output. Headphones can go to higher voltages than line level, and a headphone output is designed for a different impedence range than line level. The two are close enough that they will work together, but it's not an optimal situation and for the best sound quality you want all your inputs and outputs to be impedence matched.

    3. Macs have very nonstandard interfaces. For example, the "headphone" jack on the ibook is actually a TRRS (tip ring ring sleeve) connector, which has contacts for audio left and right, video, and ground. A normal headphone or stereo line level jack would have three contats (TRS), for left, right, and ground. This can mean that sometimes the assumptions we make when thinking about "normal" audio stuff can lead us astray when dealing with macs.

    4. MOST stuff you will deal with that isn't a microphone will be line level. Some examples are electric keyboards, drum machines, some electric guitars, direct boxes, most effects processors, DAT decks, etc etc etc.

    The only stuff that is mic level is going to be either a mic or something mic-like (like piezo pickups on an old-school electric guitar).

    5. All of this is, at best, a guideline - the circuitry used in good audio equipment is quite sophisticated, and what holds true for one piece of equipment won't neccesarily be true for another. For example, I've used mix boards that, when set to line level, will still work with a mic level input, even though the impedence is wrong and the signal is really weak. I've seen more than one newbie tech crank the hell out of the gain on a channel when all he needed to do was push a button and switch the channel to mic level.
     
  13. trainguy77 macrumors 68040

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    #13
    I stand corrected.
    And in some cases its an absolute no no. For example a headphones out on a guitar amp, don't use that as a line level.......:eek: I had a friend make that mistake, blew the channel.
     
  14. MustardMan macrumors member

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    Apr 26, 2005
    #14
    Good point - I read my post several times trying to see if I left anything out, and completely forgot to bring that up :eek: :rolleyes:

    Be VERY wary of using any 1/4" headphone out as a line level - the big boy headphones tend to have larger drivers in them and need a hotter signal. The mini jack headphones are usually pretty safe in a pinch.
     
  15. motulist macrumors 68040

    motulist

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    #15
    As always, I feel like it's my role to ask the Captain Obvious questions.

    What exactly are you trying to do with the mic you're pluggin in? What software are you using it with? Meaning, I see that you're a newbie here, so I want to be sure you're asking the question that will get you the answer to what you're really trying to figure out. I don't know what level you're at, so the answer to what you're asking could actually be to tell you that just plugging a mic into the jack will not do anything without software that uses it. So just plugging a mic in won't work like a PA system. You need recording software if you want to record audio in through the audio-in jack.

    You should always include as many details about the problem you are encountering and the hardware you're using.
     

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