Late 2008 MB/MBP microphone input

Discussion in 'MacBook Pro' started by fathom, Jan 29, 2009.

  1. fathom macrumors newbie

    Joined:
    Oct 25, 2008
    Location:
    Irvine, CA
    #1
    Some background for my question:

    So, as many of you know, the new "late 2008" macbooks and macbook pros have a "hidden" microphone-level input in addition to the traditional line-level input. The microphone input is inside the headphone jack and uses the iPhone-style plug (with three connections or poles on the minijack plug). For example, you can plug in the new in-ear headphones with the microphone to the MBP and utilize the plugged microphone on the MBP. In the Sound Preferences you can see the input source switch from "Internal Microphone" to "External Microphone" as you plug in such a headset.

    The question:

    I would like to plug in a traditional microphone and/or a guitar input. These are microphone-level inputs. However, does anyone have any idea how I could utilize the microphone input inside the headphone jack on my late-2008 MBP? I can imagine an adapter that would make this conversion --- quite a simple adapter.

    I could buy the cheapest iPhone headset with a mic and cut off the headphones, purchase a 1/4" jack from RadioShack, and do some soldering. But, this will result in an expensive, time-consuming, jerry-rigged solution.

    Does anyone know of any such adapters that can go from a standard 1/4" or 1/8" jack to a iPhone-style 1/8" mini plug (that connects the signal of the jack to the microphone pole of the plug)?

    This would be especially useful with the new version of GarageBand '09 that allows you to apply effects to a plugged-in guitar.
     
  2. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #2
    Why don't you just plug it in with the mic port?

    Also you should probably use a external DAC or you might fry your computer.
     
  3. fathom thread starter macrumors newbie

    Joined:
    Oct 25, 2008
    Location:
    Irvine, CA
    #3
    There is no mic port outside of the connection inside of the headphone jack. The other one is a line-level input. If you plug a mic into it, it'll be too underpowered for the computer to pick up barely any signal.

    Yeah... I don't think so. Mics and guitar pickups are passive devices (well, most are... mine are) -- they don't actually supply any current other than that which is induced on the coils from the movement of the strings (in the case of the guitar). There really is no way for it to fry anything unless you were struck with lightening.

    Thank you for your response though... I'm guessing that there really isn't any solution for this yet. But, I'm also guessing that with the new GarageBand features, someone (Griffin) will come out with something like this eventually.
     
  4. Herrow macrumors regular

    Joined:
    Jul 24, 2008
    #4
    Here are 2 products that utilize the inputs you are describing. I own both and they work exceptionally well!

    Garageband Cable

    Griffin iMic

    GarageBand 09 rocks!
     
  5. fathom thread starter macrumors newbie

    Joined:
    Oct 25, 2008
    Location:
    Irvine, CA
    #5
    So, my understanding is that the Garageband Cable doesn't in fact have the connection that I am describing. Let me demonstrate. Notice in this picture how the plug on the left has three electrical contacts, and the one on the right has four?
    [​IMG]
    That extra band at the base is the one that carries the microphone level signal. The GarageBand Cable (if I'm not incorrect) carries the signal on the contact on the tip of the plug. So, this isn't really what I'm after.

    The USB iMic would work in conjunction with the GarageBand cable. But, I'm just checking if there are any solutions that use the Mic-level input that is already on the new MBP. There are latency issues when doing analog (instrument) to digital (USB) (and sound quality issues as well).

    Thank you for your response... and in fact, your solution may be the one that I end up using if I can't find an acceptable alternative.
     
  6. fathom thread starter macrumors newbie

    Joined:
    Oct 25, 2008
    Location:
    Irvine, CA
    #6
    So, I've now done more research. I'm convinced now that there is no solution like I'm envisioning, at least currently. The best approximation that I was able to ascertain is to purchase something like this
    [​IMG]
    and splice a jack onto the microphone cord. Into that jack I could plug a mic or guitar.
     
  7. bushwakko macrumors newbie

    Joined:
    Oct 5, 2006
    #7
    got anymore information about this? it does seem that a converterer from the macbook pro headphone port to a headphone and mic port should be possible
     
  8. newnomad macrumors member

    Joined:
    Mar 2, 2003
    #8
    Reading this I believe the microphone signal is ampified inside your macbook (and not inside the iphone headset) however I would like to find offcial proof of that. Anyone from apple repair center?
    If this is the case then you simple need a 4 pins jack plug and correct wiring (and impedance) for your micophone.
    For example I have an headset lying around with a plug for audio in and audio out, it would be great if I could just cut those of and solder a 4-pin jack to it, be able to use it directly in my hp jack (bc my voip application needs to restart to recognize my griffn imic, want to be able to plug in if I have a call, and be released of all the cabel clutter and keep my usb port).
    Like an apple headphone with microphone, but one specially for voip calling.
     
  9. ehmjay macrumors member

    Joined:
    Apr 26, 2006
    #9
    what the crap!? okay I have a MBP from August 2008 (which I think means late 2008) and it doesn't detect my headphones. According to this apple tech-note http://support.apple.com/kb/HT3554 it SHOULD but doesn't! WTF!?
     
  10. fireman13 macrumors 6502

    Joined:
    Aug 12, 2008
    Location:
    Florida Panhandle
    #10
    I think he may mean the unibody October editions when he refers to the late 08 models. I may be wrong though.
     
  11. ehmjay macrumors member

    Joined:
    Apr 26, 2006
    #11
    but it also says early 2008 which would be BEFORE the unibody refresh...
     

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