Camera mic question external mic only records one channel

Discussion in 'Professional Video Production' started by Tony, Jun 14, 2008.

  1. Tony

    Tony Guest

    I have a Sony TRV-900 3 chip camcorder. I do semi pro stuff. Nothing on real tv or anything. It has
    a stereo mic mini plug jack. I use a condensor mic that has a 1/4" phone plug on the end of it and
    then use a female mono 1/4" phone plug to stereo 1/8" mini plug. For some reason, it is only
    recording to the left channel. Any ideas why?

    Tony, Jun 14, 2008
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  2. You are shorting out one channel of the stereo input of the camcorder
    by doing this. You need to get a mono-to-stereo adapter, plus the
    1/4" to 1/8" adapter. The Radio Shack adapter part numbers are in
    my review of the Canon HV20 (in the "sound" section), at --
    Also, common problem with the TRV-900 was the loss of one
    channel. Because of the way the two mics are set up inside this
    camcorder (crossed cardioids, as I recall), this often goes unnoticed
    until an external mic is attached.
    --David Ruether
    David Ruether, Jun 14, 2008
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  3. Tony

    Tony Guest

    I made a mistake in my original post. I meant to write that I was using a 1/4" female mono to 1/8"
    stereo adapter that plugs into the camera. So, since I believe I am doing this correctly, is it the
    TRV900 that has the problem? What I have been doing is bringing all my footage into Soundforge,
    copying one channel and pasting it to the other so that I have two channels of the same audio in
    left and right speakers.

    Tony, Jun 14, 2008
  4. "You are shorting out one channel of the stereo input of the camcorder
    by doing this." The stereo jack in the camcorder has contacts for both
    the "hot" tip and (short) ring of the "expected" stereo plug. When you
    put a mono plug into the jack, the ring is shorted to ground in the
    camcorder, giving you no right channel signal. You need an adapter
    that takes a mono signal and feeds it to both the tip and the ring to
    get two-channel mono. You can also do what you are doing (duplicating
    the left channel into the right channel in a sound editor), but it is easier
    do it in the camera while shooting. (BTW, I'm dealing with the same
    issue, since the only mic I have that is wind "bullet proof" is a mono short
    shotgun with a wind screen plus a "fuzzy" - and I prefer mono with no
    wind noise to stereo with it.)
    --David Ruether
    David Ruether, Jun 14, 2008
  5. It is working exactly as intended. Since you are using only one
    microphone, and since you are using an adapter wired for mono
    it is recording only one track. There is nothing wrong with just
    copying the sound from one channel into the other channel if
    you want.

    It doesn't sound like anything is wrong here. If you want to
    record to both channels, then you need to use an adapter wired
    properly. Or use a stereo mic.
    Richard Crowley, Jun 14, 2008
  6. Tony

    Ty Ford Guest

    Does the plug on the end of your mic have one or two dark bands?


    Ty Ford

    --Audio Equipment Reviews Audio Production Services
    Acting and Voiceover Demos
    Guitar player?:
    Ty Ford, Jun 14, 2008
  7. If I understand correctly (emphasis in your post is mine), your adapter is
    also meant to convert from mono to stereo, right?

    I've dealt with such adapters that did not adapt like they were supposed
    to. My guess is try two adapters: one 1/4" to 1/8", and one mono to stereo.
    If that does not work still, you may have a problem with your camera.

    My wireless lav mic is mono. I don't bother with an adapter, I just fill
    the single channel to both stereo channels. There should be a function like
    that in your editing software (there is in Vegas and Premiere) without
    requiring you to cut and paste. In Premiere, it's called "Fill Left" or
    "Fill Right".

    Jacques E. Bouchard, Jun 14, 2008
  8. "Jacques E. Bouchard" wrote ...
    Unlikely. Adapters wired like that are not commonly
    available commercially. You have to make it custon.
    Tony has a mono source and is feeding it into only the
    Left channel of the camcorder. The camcorder is working
    exactly as designed. Unless Tony bought a special adapter
    made specifically for a mono source to feed a stereo input,
    then there is nothing wrong with his mic, cable, or camcorder.
    Agreed. Recommend just using it as is and diddle the tracks
    to taste in post-production editing.
    Richard Crowley, Jun 14, 2008
  9. True, but there is a Radio Shack 1/8" mono-to-stereo adapter (RS number
    274-374, $2.99) that converts mono to stereo (1/8" both sides). An
    additional 1/4" to 1/8" mono adapter would be needed to make this work...
    --David Ruether
    David Ruether, Jun 14, 2008
  10. Phew, I was afraid I was imagining things.

    Incidentally, the Radio Shack stores have been bought out by Circuit City
    up here. Same crappy overpriced merchandise, though. Great if you need
    something in a hurry, but they now favour "boutique" cables (i.e. low
    quality but fancy packaging) and their parts stocks have dwindled to
    almost nothing to make room for consumer electronics.


    Jacques E. Bouchard, Jun 14, 2008
  11. Tony

    Tony Guest

    Why wouldnt my 1/4" mono to 1/8" stereo adapter do the work. As far as I can see, the mono signal
    from my mic would go into the 1/4" jack, then get sent to the stereo 1/8" plug, which would feed my
    stereo jack in my TRV900. RIght now, it is ignoring the stereo adapter.

    Tony, Jun 16, 2008
  12. I don't believe that you really have a "1/4 mono to 1/8 stereo"
    adapter. I'd bet money that it is NOT wired for mono to stereo.
    I'd bet that it is wired for stereo to stereo and that is why your
    camcorder is picking up the audio only from the left channel
    (the tip of the mono connector).
    But only to the tip (left channel).
    The ring (right channel) is grounded/shorted by the
    sleeve of the 1/4 inch jack.

    It takes a special mono-to-stereo adapter to do what you are
    asking and you don't seem to have one. Again, I'm not sure
    why it is worth all this discussion? You don't have the right
    adapter. It is not a show-stopper. Live with it.
    Richard Crowley, Jun 17, 2008
  13. Tony was pretty clear from the start that his adapter is supposed to
    convert from mono to stereo. That was the point of his post, to determine
    whether there might be something wrong with his camera. However, as
    others suggested, it's probably the adapter that doesn't work as
    intended, or that isn't mono-to-stereo.

    Jacques E. Bouchard, Jun 17, 2008
  14. "Jacques E. Bouchard" wrote ...
    Tony's original post says nothing about a stereo to mono
    adapter. Suggest reviewing the messages to refresh your
    memory. And his second post clearly says that he is using
    a 1/4-inch stereo to 1/8-inch *stereo* adapter. His symptoms
    are entirely consistent with that information.

    That was the point of his post, to determine
    Richard Crowley, Jun 17, 2008
  15. I just did. He said he "...use a female mono 1/4" phone plug to stereo
    1/8" mini plug". I certainly took that to mean a mono to stereo adapter.
    Actually his exact words were "...a 1/4" female mono to 1/8" stereo
    adapter", confirming my first impression.

    I thought his question was perfectly valid.

    Jacques E. Bouchard, Jun 17, 2008
  16. "phone PLUG" refers to the connector on the end of the mic
    cable which plugs INTO the stereo adapter. Perhaps a review
    of the meaning of "plug" and "jack" would be in order, also.
    Yes, his question is perfectly valid, and his descrption of his
    symptoms are entirely consistent with use of a stereo adapter
    for a mono signal source.

    I was doing audio for a decade even before video (i.e.
    ~45 years). I've seen exactly this situation happen
    dozens of times. This isn't some new phenomenon.
    Richard Crowley, Jun 18, 2008
  17. Tony

    Tony Guest

    I started this post. I said I have a 1/4" mono female phone plug connector on one end and a 1/8"
    steero mini plug on the other side. I have had a recording studio for 15 years and a phone plug is
    1/4". It got the name phone plug because telephone operators used them when they had to patch phone
    lines at the switchboard. The question I wrote is valid and what I have should do what I want it to
    do, unless the adapter I bought is defective or is not what it says it is. I will simply buy another
    adapter and see if it solves the problem.

    Tony, Jun 18, 2008
  18. Rope in that sneer, I know perfectly well the difference between "jack" and
    "plug". I also knew what the poster meant, and he very clearly clarified
    that in his second post.
    Is it consistent with using a MONO to STEREO adapter? Because he made it
    clear that is what he is using.

    Jacques E. Bouchard, Jun 18, 2008
  19. "Jacques E. Bouchard" wrote ...
    Yes and I believe that I made it clear that I don't believe that
    Tony really has a "mono to stereo adapter". Case closed,
    this is getting ridiculous.
    Richard Crowley, Jun 18, 2008
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