View Full Version : Mic starts out loud and fades out


Brit Mansell
February 4th, 2010, 09:00 PM
Ok, so I'm very confused here. I'm using both of the XLR inputs. One is connected to a shotgun mic and the other is connected to a headset mic. The idea was to be able to interview people and hear the audio at the same time through the headset, so I bought one of these: Plantronics - GameCom 777 Stereo Headset with Dolby Technology - Black - 79733-01 (http://www.bestbuy.com/site/Plantronics+-+GameCom+777+Stereo+Headset+with+Dolby+Technology+-+Black/8978467.p?id=1218004380179&skuId=8978467&st=computer%20headset&cp=2&lp=8)

I have connected the headset mic (analog) output to the HM100u via a XLR to 3/8 plug (the headphone side of the headset is connected to the headphone out on the camera). The odd thing is, is that it starts out at normal volume as soon as I connect it, but the volume fades from normal to almost zero in about 15 seconds. This is 100% repeatable. I also have a Rode VideoMic (also with 3/8 plug) that is powered. When I plug it into the same plug to the camera, the volume stays consistent and correct.

So, why is the volume fading to zero with the non-powered mic, and how can I prevent it?

Thanks in advance.

Brit Mansell
February 4th, 2010, 10:25 PM
So I've been "googling" around since I posted this and I think I have determined the problem. The XLR inputs require "plug-in power". If I plug in the mic output from the headset into my Sennheiser lavalier mic everything works fine. So, obviously, the mic input on the HM100u expects the mics to be powered, even when used with the +48v setting.

I think I have two options:
1) Find a headset with a powered mic
2) Find an adapter that provides the power

Any suggestions?

Brit Mansell
February 5th, 2010, 08:27 PM
Surely somebody has a suggestion? Anybody?

Robert Rogoz
February 5th, 2010, 11:42 PM
you might have to buy something like Juicelink or Beachtek adapter.

Brit Mansell
February 6th, 2010, 07:39 AM
Yeah, but that seems like an extreme action to take for such a simple need.

Basically, all I need is a headset with microphone that I can plug into one of the XLR ports on the camera. It sucks that I can use the crappy gaming headset when I use the 1/8" mic port on the camera, but not through XLR. I understand the difference between XLR and normal mic plugs, but I just wish there was an easy (compact) way to convert to powered (or phantom) XLR from passive mic's.

Mike Beckett
February 6th, 2010, 11:03 AM
Brit,

Not sure if I grasp the set-up here (and I'm not a JVC person). Is the purpose of the headset mic to record your voice as the interviewer and the shotgun for the interviewee?

Leaving aside whether an on-camera shotgun mic is good for interview or not, if I was trying to do that I would try a lav mic via a simple Rode-style mini jack to XLR converter to record my own voice. Then use a set of headphones to monitor (or just use the gaming set but without the mic plugged in).

Even a $35-ish ATR35 lav mic would do, and it is self-powered. I'm not sure the audio quality through the gaming headset mic would be brilliant anyway. All in, that might cost you $40 or $50 tops.

I have a feeling that trying to get the gaming headset to work might be a waste of time, but there may be more knowledgeable people than me who could comment.

Robert Rogoz
February 7th, 2010, 12:11 PM
Just unplug the sound handle and plug the receiver into 3.5 mini. You won't get uncompressed, but with this type of recording you can't expect high quality anyway.