Need help inputing audio into Vixia HC30

[jbaugh]

I am doing live audio/video streaming using a Vixia HV30 camcorder set to HDV30p. The audio I wish to capture is too far from the camera for the built-in mic to pick up an adequate signal. There is a line level audio signal that I have been inputting into the streaming computer through the line input jack. The video is input via Firewire. But the audio and video are out of synch with this setup. The video lags the audio by about half a second. Is there a way for me to feed the audio signal into the Vixia rather than into the computer input? If I could do this I would clear up the dys-synchrony. The audio and video would both be inputted into the computer over Firewire. There is a mic input terminal on the camcorder. But I am hesitant to plug the line level signal into this port. Would this damage the camcorder? Is there a way to accomplish what I am after?
Thanks.
John

I should mention that when I was doing the live broadcasting previously using a SD camcorder with the audio input into the computer there was no problem with synchrony. I suspect that now there is a greater time lag involved in processing the HD video thereby allowing the audio to precede the video.
John

[_Al_]

You need to bring it down 50dB
https://www.google.com/#hl=en&cp=7&gs_id=1h&xhr=t&q=stereo+50+dB+attenuator&tok=coHb1_...w=1920&bih=908

I use this for HV30 http://www.bhphotovideo.com/c/product/136397-REG/Beachtek_DXA_4_DXA_4_Audio_Adapter.html which perhaps does what you need but never tested that , I use only microphon with it, check specifications

[jbaugh]

Thanks for the helpful response. I went to my local Guitar Center and they highly suggested a passive Direct Box which apparently does the same thing as the devices you mentioned– convert line level to mic input level. I tried it out but it didn't work very well. I got a very poor audio signal with lots of noise.
Ill have to come up with a solution that does not involve inputing the line signal into the camera.
John

[edDV]

Thanks for the helpful response. I went to my local Guitar Center and they highly suggested a passive Direct Box which apparently does the same thing as the devices you mentioned– convert line level to mic input level. I tried it out but it didn't work very well. I got a very poor audio signal with lots of noise.
Ill have to come up with a solution that does not involve inputing the line signal into the camera.
John

Can you describe the audio system from mic to mixer to camcorder input?

The more detail the better.

[jbaugh]

edDV,
You asked for it so here I go. I'm sorry to be so long winded but I don't know how else to give you all the details.

Starting at the mic inputs: One lavalier Sennheiser wireless and one wired omnidirectional conference type mic are connected to a Profire 610 Firewire interface. This connects to a Mac Pro via FW interface. Audio recording is done on the Mac Pro using either Sound Studio or Audacity. This portion of the work flow works fine and is mentioned for completeness sake.

The mixed microphone signal is then routed from the Profire 610 (a pair of line outputs on the back of the Profire 610 which are "y"ed together to an audio cable to create a mono signal) to the back of the auditorium about 80 feet away to be used as the audio signal for live broadcasting. This is handled by a Mac Mini (newest iteration dual i7 with 8GB RAM and 7200RPM HD). Wirecast is used for the broadcasting encoder. The Mac Mini is connected to the LAN via ethernet cable. The audio cable to the back terminates in an XLR connector.

The current set up at this point involves connecting the XLR connector to the XLR input on an M-Audio USB interface. The RCA outputs on the back of the USB interface are connected to an RCA to 1/8 inch "y" cable and this is connected to the line input on the Mac Mini. This serves as the audio input source for the live broadcasting. The single camcorder is a Vixia HV30 which is connected to the Mac Mini via FW port. So the audio signal does not come from the camera because the camcorder is too far away for the attached external mike to pick up a decent signal. This set up has worked quite well for the past 8 months or so as long as the camcorder was configured in SD mode.

Now I've introduced a major problem in the mix by trying to configure the camcorder to provide a higher definition feed. I have set the camcorder to HDV30P mode. I get a dramatically improved video output in the broadcast now but I have caused dys-synchrony between the audio and video. The audio now precedes the video by something like 1/2- 1 second. The problem seems to be caused by a slight delay in processing the more data intense video by my encoder which allows the audio to play early out of synch.

The simplest solution to this problem would seem to be feeding the audio from the line feed directly into the camcorder so that both the audio and video come from the camera to the encoder simultaneously. This certainly works and results in synchrony when the internal mic or external boom mike supply the audio.
The camcorder has a 1/8 inch mic input that could be used for signal input. Indeed I have tried to do this but so far without success. I've mentioned above my attempt to use the Direct Box device without success.

For now I've reverted back to SD video and inputing the audio directly into the Mac Mini. I can live with this set up but I really was impressed with the improved quality of the video when I was broadcasting with the HD setting.

I apologize for this long post and my rambling. I'm really a novice at this sort of thing and I've probably left out some important details.
Thanks for taking time to try and sort this all out.
John

[edDV]

Got it. The M-Audio 610 is a nice box. It can probably do a mono mix without using the Y cable. In analog mode it outputs balanced 600 ohm line level which is good for a couple hundred feet.



The Canon HV30 requires unbalanced high impedance mic level.

The most elegant solution would be a Beachtek DXA-2T at the camcorder. This could also be used to connect your mics directly for field shooting.

http://www.beachtek.com/
http://www.google.com/products/catalog?q=beachtek&oe=utf-8&rls=org.mozilla:en-US:eek:f...ed=0CGIQ8wIwBw

Other similar devices
http://www.markertek.com/Audio-Equipment/Camcorder-XLR-Adapters.xhtml

I'll look for lower cost alternatives. What is needed is a balanced line level to consumer mic level converter. Others might have suggestions.

[jbaugh]

Thank you very much! I feel like I've just had a personalized professional consultation at a cost that can't be beat. I still am struggling with understanding the difference between "balanced" and "unbalanced" so you can see the level of my knowledge and experience with audio technology. Most of what I've learned has been through trial and error and input from knowledgable people like you. Indeed, setting this up has been one trial after another with lots of error. But it has been an enjoyable learning experience. I started less than 2 year ago with no clue about audio/video technology and now I am recording and live broadcasting three services a week for my small church.

The Beach Tek unit you suggest might be a good solution for me. The price is probably at the higher end of what I can afford for this purpose. Just to be sure I understand how this works– I suppose this would interface directly with my XLR- terminated cable and the USB interface would be removed from the equation? The only thing that worries me about this is that when I bypassed the USB interface and connected the audio cable to my computer via an XLR to 1/8 inch plug the audio volume was low even with the computer volume set to maximum. The USB interface seemed to be boosting the signal sent to the computer.

Thank you for the time and effort it has taken you to help educate a confused newbie. I really appreciate it.
John

[edDV]

Profire 650 out line level (balanced) to DXA-2T (switched to line level in). Then the DXA-2T feeds the HV30 at mic level (unbalanced). USB/Firewire not used unless you want to record an audio track backup to a PC.

http://en.wikipedia.org/wiki/Balanced_audio