lav mic causing interference with in camera mic?

[Paunch]

I shot a wedding and the audio from the camera mic tends to cut out, the wireless stuff was fine but the camera audio seems to pulsate a bit and is pretty useless...what settings should my audio be at when recording 2 channels? 16bit or 12bit?

I noticed the audio cutting in and out occurred more often when the lapel mic was picking up direct audio during the vows and stuff. basically i'm left with nothing to cut to for audio when the wireless audio rubbed against the clothing of the groom.

 

[Alex H.]

Always, always, always 16 bit! 12-bit/33kHz audio was a consumer marketing tool for cameras to cheat a second stereo pair... it allowed folks to overdub narration or add music in-camera for little Jimmy's soccer game. It's a waste of time to deal with 12-bit, and a detriment to your audio.

As for the issue at hand, can you post a sample clip of this problematic audio?

Also, what camera are you using, and how do you have these mics connected? Any external mixer? Adapters, Y-cables, converters?

 

[Gohanto]

16 bit, never 12bit. It's a needless drop in quality.

My first guess would be RF interference at the mic. Which can be a lot of things from cell phones to power lines, but I've never heard of a wireless mic system causing an RF problem.

 

[ZeroContent]

Since you said it happened mostly with when there was good audio on the lav. It could be the camera if you were going straight into camera. Could be that the audio level is automatically adjusting both channels instead of just the one that is loudest, some type of limiter?

 

[Paunch]

i use a dvx100, and the ALC was turned on at the time.

 

[Alex H.]

i use a dvx100, and the ALC was turned on at the time.

ALC on the DVX is a limiting control, not a level control. It should not have affected one channel from peaks on the other. Did you have any kind of external mixer connected, or were the mics straight into the camera? Where were the levels peaking on the meters?

Again... posting a sample for us to hear will help.

 

[Paunch]

lav was plugged into the xlr jack, and the other was the on board camera mic. I usually let the levels hit a few red but no more than 3 bars.

 

[j1clark@ucsd.edu]

lav was plugged into the xlr jack, and the other was the on board camera mic. I usually let the levels hit a few red but no more than 3 bars.

Since I am learning about audio things... when you plug two sources into your camera, and presumably, handle the sources as independent mono channels, how do you listen to them. I presume you separate them via your NLE, and then turn one or the other on at a time. Also, I presume that you don't turn on any automatic gain or limiting control on either.

Just as an aside, I've never used my DVX100 in this mode, but can you have one of the audio inputs associated with the XLR plug, while the other channel is associated with the internal camera mic?

I thought it was either internal and stereo, or external channels one and two... but perhaps that's the DVX.

 

[Alex H.]

Also, I presume that you don't turn on any automatic gain or limiting control on either.

Read up the thread a little... he's had ALC on, but that may not be the issue.

Just as an aside, I've never used my DVX100 in this mode, but can you have one of the audio inputs associated with the XLR plug, while the other channel is associated with the internal camera mic?

I thought it was either internal and stereo, or external channels one and two... but perhaps that's the DVX.

Both record channels on the DVX, as with most professional cameras, are completely independent of each other when it comes to input control.

 

[j1clark@ucsd.edu]

Both record channels on the DVX, as with most professional cameras, are completely independent of each other when it comes to input control.

I've not used that mode very much, but I'm going to be for The Wife, and her podcasts. She wanted some 'vintage' microphones for a 'look', and so we got some 'shells'. I'll be hooking up small mics out sight from the camera on the inoperable mics, as well as a real mic outside the video frame.

 

[Steve House]

I've not used that mode very much, but I'm going to be for The Wife, and her podcasts. She wanted some 'vintage' microphones for a 'look', and so we got some 'shells'. I'll be hooking up small mics out sight from the camera on the inoperable mics, as well as a real mic outside the video frame.

Why not use real 'practical' mics instead of using props and then having to hide the functional mics? Take a look at the movie "A Prairie Home Companion" where all of the mics (most of the stage vocals on EV RE-27's, I believe Keilor's is a classic RCA ribbon mic, with a scattering of other types micing the band) seen on-camera in the stage scenes were the actual, functional mics recording the production sound used in the final film.

 

[j1clark@ucsd.edu]

Why not use real 'practical' mics instead of using props and then having to hide the functional mics? Take a look at the movie "A Prairie Home Companion" where all of the mics (most of the stage vocals on EV RE-27's, I believe Keilor's is a classic RCA ribbon mic, with a scattering of other types micing the band) seen on-camera in the stage scenes were the actual, functional mics recording the production sound used in the final film.

In the time frame we were looking, and given it was e-bay, most of the 'functional', at least claimed to be functional, mics were going for about $50 or more. Even some non-functional, but 'odd' mics were going for more than we wanted to pay for essentially a prop.

At the moment I'm getting ready to go to Las Vegas to a professional trade show (audio/video unrelated...), then it's Burning Man, so I probably won't be able to look at e-bay for the rest of the month. So, it was get something to work with.

Perhaps in the future, we'll get functional units. One class was 20's, early 30's in the circular spring suspension setup. Then another in the mid-50's. We saw some number of Shure 55S, but still they seem to be going for more than we wanted to pay.

I watched "Good Night, Good Luck" they other night and saw a couple of mics that were similar to some I saw on e-bay, but again too much. I also watched "The Day The Earth Stood Still"(1950), and saw a few more...

As in:

 

[Rippie]

Why not use real 'practical' mics instead of using props and then having to hide the functional mics? Take a look at the movie "A Prairie Home Companion" where all of the mics (most of the stage vocals on EV RE-27's, I believe Keilor's is a classic RCA ribbon mic, with a scattering of other types micing the band) seen on-camera in the stage scenes were the actual, functional mics recording the production sound used in the final film.

just make sure they dont come from a prop house.
Everytime ive ever plugged into one to see if I could get usable audio
through them..they are always horrid sounding.