Mic Input Distortion

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Laptop computer Hardware and Software discussion

Mic Input Distortion

  • I have a Inspiron 8600 which is only a month old. Can someone help me please on how to record via mic input without major distortion, I have updated drivers and been through all the diagnostics but nothing seems to fix the problem. I have set all volume to a minimum setting and still no go, it seem to receive audio at a very high level even though my external audio device volume is very low. Dell support don't seem to know what the problem is. Does anyone have this problem or am I missing something?
  • Hi

    Sometimes if the Mic Boost is enabled it might give such distortions.

    1. Click on Start - Programs - Accessories - Entertainment - Volume Control

    2. Click on Options Properties - Choose Recording - Click Ok

    3. Under Microphone - Click on Advanced and uncheck the mic boost options.

    This might help in some cases.

    The Apostate.

  • Thanks, but I have tried the Mic Boost. There seems to be too much signal coming through the Mic input, but no way to control it.
  • What kind of 'external device' are you talking about?

    Jim

    Jim Coates -- senior forum member


  • The external device is an analogue JVC Camcorder, using a Belkin external USB Capture device. The Audio is going direct from camcorder to the Mic input on my 8600. The signal received is way too much, it also does it from other machines such as VCR recorder and cassette decks. I thought it might have been the external devices but they all work fine on my IBM, so it has to be the Mic input that cannot handle it.
  • fox,

    have you tested the mic jack with a mic? If it tested out ok then I would think that you have correctly described the problem, that these devices are sending line level signals which are too hot for the mic circuit. If you can't attenuate the signals to mic level then you probably will need an external (usb, pcmia, firewire) soundcard with a line input.

    Jim

    Jim Coates -- senior forum member


  • Thanks, yes I have tested the Mic input with a Microphone and the same thing, I used an external sound mixer (Beringer) to control the input signal and it was still distorted but at a lower volume level. If had known the 8600 had this problem I would not have bought it. Do you know of any other registry tweaks I could try?


    Thanks again....fox
  • fox,

    As I understand it, you ran the mic signal thru the mic preamp of the mixer. The signal output by the mixer to the computer would then be a line level similar to the other external audio devices you have tried. I would suggest that you test the mic jack for a defect by plugging the mic directly into the jack, and probably you would have to turn 'mic boost' on. If the mic level signal distorts like the line level signals do then you probably have a defective unit.

    I don't know of a registry tweak for this but you might try the Intel driver if your machine has it.

    FYI I have an i1100 with the SigmaTel chip. My mic jack does accept line signals without problems although I never use it for that purpose because it is a mono jack.

    Jim

    To install the generic Intel driver without uninstalling SigmaTel :

    > Go to Start/Control Panel/System/ Hardware tab, then click on Device Manager. Go down to Sound, Video, and Game controllers and right click on SigmaTel. Choose properties.
    > Go to the Driver tab and click on Update Driver.
    > Answer "No" to the Windows Update question.
    > Choose "Install From List or specific location".
    > Hit next and then choose "Don't Search, I will choose driver I want to install".
    > You will get a list of Sigmatel drivers. Uncheck the box that says "show compatible hardware".
    > Select Intel, and then select "Intel AC 97 Audio Controller". XP replaces the SigmaTel driver with the Intel AC97.
    > To reinstall the SigmaTel just select "Rollback Driver".

    Jim Coates -- senior forum member


  • I have the same problem and installing the intel driver did not work.

    My software supplier said to only put a mic in the mic jack. She said to use the line-in jack. I can't seem to find that.

    Any suggestions?
  • I could not use the mic input, even Dell could not tell me why. I fixed my problem with a Creative External Live 24bit Sound Card, it works great. Also the Creative Digital Music LX External is just as good. I gave up with Dell support, all the registry tweaks and different drivers won't work so the only option was an external sound card.....hope this helps..

    Fox


  • jimco wrote:
    fox,
    To install the generic Intel driver without uninstalling SigmaTel :

    > Go to Start/Control Panel/System/ Hardware tab, then click on Device Manager. Go down to Sound, Video, and Game controllers and right click on SigmaTel. Choose properties.
    > Go to the Driver tab and click on Update Driver.
    > Answer "No" to the Windows Update question.
    > Choose "Install From List or specific location".
    > Hit next and then choose "Don't Search, I will choose driver I want to install".
    > You will get a list of Sigmatel drivers. Uncheck the box that says "show compatible hardware".
    > Select Intel, and then select "Intel AC 97 Audio Controller". XP replaces the SigmaTel driver with the Intel AC97.
    > To reinstall the SigmaTel just select "Rollback Driver".




    Cool! The Intel AC97 driver rocks!
    I had problems sending audio from my radio through the microphone jack (suitably converted to mic-levels using a matching audio transformer). Using the supplied SigmaTel C-Major drivers, the Line-In & Microphone inputs were both hidden. I suspected they were set to Mute.

    Installing the Intel AC97 driver exposes these 2 controls and more!

    fox123, u might want to try using a matching audio transformer to "convert" the line-out signal to the correct microphone level signal. Perhaps a Radio Shack could help you out.
    More details:
    http://www.mediacollege.com/audio/microphones/impedance.html
    http://en.wikipedia.org/wiki/Impedance_matching#Impedance_matching_devices