View Full Version : Split Audio


Kellen Dengler
January 7th, 2008, 10:27 AM
Over the weekend I was filming some casting interviews and I was using my brand new Rode NTG shotgun mic. I was running it through XLR Channel 1 and was getting great audio pick up. However, I was only getting it through the left earphone. I was pressed for time and didn't have time to fool with the settings in front f the client, but is it possible to get sound from the XLR on both channels? Or would that require a mic on each channel?

More importantly, in the future I was hoping to have the Rode on channel one to get direct sound and then use the built in camera mic to pick up ambient noise. Is this possible? It seems like when I turned on the XLR function in the menu to get sound from the Rode the camera mic turned off...

THANKS!

Paul Joy
January 7th, 2008, 10:56 AM
Hi there.

Yes you should get audio on both channels from the XLR, check the switches on the XLR block and make sure the bottom right switch is set to the right (CH1 & CH2).

I don't think it's possible to mix the built in mic and the XLR on the A1 unfortunately.

Alan Craig
January 7th, 2008, 11:33 AM
kellen as Paul said it is not possible to use both the xlr inputs and onboard mic together. If you want torecord main subject on one mic and ambient on another you will have to connect two xlr mic's to your camera and set mic inputs to ch1 you will also be able to adjust mic sensitivity with the two audio control wheels on the side of the camera below the lcd latch. Hope this is of help.

Alan

Kellen Dengler
January 7th, 2008, 12:14 PM
Thanks guys. This answers my question.

It's a shame you can't use the camera mic along with a shotgun. Every ENG camera I've used at different jobs always allow the use of an auxillary mic AND the camera mic for ambient noise.

What are some of you other A1 users doing to acquire both direct sound from your subject and ambient sound? Are you using 2 XLR mics?

David McGiffert
January 7th, 2008, 08:13 PM
Kellen,

Yes, that's what I'm doing;
I'm using a radio mic on my subject
and a shotgun mic. Both XLR's.
I dial the shotgun mic 'way down and it aproximates
ambient fairly well...

David

Benjamin Hill
January 7th, 2008, 10:33 PM
Thanks guys. This answers my question.

It's a shame you can't use the camera mic along with a shotgun. Every ENG camera I've used at different jobs always allow the use of an auxillary mic AND the camera mic for ambient noise.

What are some of you other A1 users doing to acquire both direct sound from your subject and ambient sound? Are you using 2 XLR mics?

Yes it's a shame, especially considering that the Canon on-board mic actually sounds pretty nice. I use a Rode shotgun as my ambient/backup when I have a wireless or lapel mic in the other channel.

Another little shortcoming is the inability to use mic/line level separately on the channels. Love the Canon HDV cameras but I'll gripe about this problem every chance I get.

Bill Busby
January 7th, 2008, 11:35 PM
Another little shortcoming is the inability to use mic/line level separately on the channels. Love the Canon HDV cameras but I'll gripe about this problem every chance I get.

ditto! :-\

Bill Pryor
January 8th, 2008, 10:12 AM
"Every ENG camera I've used at different jobs always allow the use of an auxillary mic AND the camera mic for ambient noise."

The "camera mic" on an ENG camera is a separate mic that happens to be mounted on the camera--it's not a built-in mic like the 1/3" chip cameras have. However, you can do the same thing--put a short shotgun on the camera and run a second mic into the other XLR input. Just ignore the built-in mic, and you have the same capability. The ENG camera may "come with" a mic, but you pay for it. With the smaller cameras, you buy the mic separately. What I use for a camera mic is the Sony short shotgun mic that came with my old 2/3" chip Betacam camera.

Benjamin Hill
January 8th, 2008, 11:29 AM
The point is, whether you have a built-in mic or a camera mic you should still be able to use it in conjunction with a second mic, and on the darn Canons, you can't.

Colin McDonald
January 8th, 2008, 12:23 PM
Over the weekend I was filming some casting interviews and I was using my brand new Rode NTG shotgun mic.

I think your main question has been answered now. I have used the Rode NTG-2 as sole microphone and also as ambient with a Sennheisser EW-112PG2 Camera set for the main audio. I have to say I was disappointed that I can hear zoom motor noise quite clearly from the Rode when it's mounted on the built in microphone mount. Anyone else find this and is there a workaround apart from mounting it on a stand (not portable) or boom (extra crew)?

Also, it doesn't seem to fit the mount particularly well and I have to pad the mount to keep the Rode securely attached.

Kellen Dengler
January 8th, 2008, 02:43 PM
Yeah my Rode is too small for the mic clamp thing as well. I took some gaffers tape and ripped about a half inch strip and wrapped it around the mic so it fits snug in the clamp. I haven't noticed a ton of motor noise, but I was recording at a very low level.

Is this happening in auto zoom/focus or manual or both?

Alan Craig
January 8th, 2008, 03:04 PM
I only hear motor noise when zooming fast not when zoomin slow-medium speed.

Alan

Colin McDonald
January 8th, 2008, 03:57 PM
Is this happening in auto zoom/focus or manual or both?

I only noticed this on manual zoom, however slow, but not on focus. The camera was on a gallery in a church and little refocussing was required, but I did try out lots of framing/focal length changes.

It sounded as if if might have been electromagnetic in origin rather than acoustic vibration but I don't know. There was very little background sound during the preaching (not even snores - the guy was good but not OTT).

Benjamin Hill
January 8th, 2008, 05:17 PM
I think your main question has been answered now. I have used the Rode NTG-2 as sole microphone and also as ambient with a Sennheisser EW-112PG2 Camera set for the main audio. I have to say I was disappointed that I can hear zoom motor noise quite clearly from the Rode when it's mounted on the built in microphone mount. Anyone else find this and is there a workaround apart from mounting it on a stand (not portable) or boom (extra crew)?

Also, it doesn't seem to fit the mount particularly well and I have to pad the mount to keep the Rode securely attached.

My Rode came with it's own shockmount that goes in the shoe, have you tried something like that? I have noticed the noise too, recently.

Bill Watson
January 8th, 2008, 06:57 PM
http://www.dvinfo.net/conf/showthread.php?t=96605&highlight=a1+motor+noise

Petri Kaipiainen
January 9th, 2008, 02:34 AM
One thing to remember when wanting to use built-in mic simultaniously with external is the sad fact that the camera mic is stereo (ENG cam mics are usually mono). There would have to be even one more switch to sum the mic to mono for this purpose, that would mean at least 2 more switces on the camera to make all possible combinations available.

I would still like to have it, also a MS mic on-cam not XY, it would be easy to default to M mic only when using internal/external combo. I would be so easy to make a "perfect" audio camera, Pana DVX100 comes quite close, should we send one to Canon design department?

Colin McDonald
January 9th, 2008, 05:22 PM
My Rode came with it's own shockmount that goes in the shoe, have you tried something like that? I have noticed the noise too, recently.

I'm getting a Rode SM3 hotshoe mount. That should damp it and let me mount the NTG-2 in a number of positions further away from the source of the motor noise using different brackets like the PAG 1021.

Colin McDonald
January 9th, 2008, 05:25 PM
http://www.dvinfo.net/conf/showthread.php?t=96605&highlight=a1+motor+noise

And thanks for the link, Bill. I haven't quite got the hang of searching dvinfo before posting.

Benjamin Hill
January 9th, 2008, 05:36 PM
I'm getting a Rode SM3 hotshoe mount. That should damp it and let me mount the NTG-2 in a number of positions further away from the source of the motor noise using different brackets like the PAG 1021.

The SM3, that's the one- today I compared it with the on-camera mic holder and it was much, much quieter- almost no zoom noise, and much less camera-handling-rumble transmitted to the mic. Plus I don't have to pad the mic to make it fit inside the Canon's oversized mic-holder.

David McGiffert
January 9th, 2008, 06:36 PM
There is definitely zoom motor noise picked up by an ext. mic
if it is not shock mounted.
I had this problem and it immediately went away
when I got a shock mount.

It is an easy fix and well worth it.

David

Don Palomaki
January 10th, 2008, 07:40 AM
I can hear zoom motor noise quite clearly from the Rode when it's mounted on the built in microphone mount.

These may not be the total solution, but they do influence the the recorded sound

One factor that may make things worse is over-tightening the mic clamp. If it is too tight it no longer provides vibration damping. It should be just tight enough to hold the mic from sliding.

Using audio AGC will make any camcorder noise more noticeable during quiet periods in program. Also, using an on-camera mic to capture sound sources from a distance (e.g., dialog from a distant speaker) can make nearby noise sources more apparent because the gain is high. For the same recorder voice level, the gain (and thus background noise) will be about 20 dB higher for a person 20 feet from the mic compared to the person 2 feet from the same mic.

The mic, even a good shotgun, should be within a few feet of the speaker for decent sound. On the camcorder is not a good location for obtaining great sound, but often it is the only practical option available. About the only worse place is in the camcorder body.

Colin McDonald
January 16th, 2008, 05:15 PM
The SM3, that's the one- today I compared it with the on-camera mic holder and it was much, much quieter- almost no zoom noise, and much less camera-handling-rumble transmitted to the mic. Plus I don't have to pad the mic to make it fit inside the Canon's oversized mic-holder.

OK, got my SME shockmount and the zoom noise has almost completely gone. The hum I heard originally was almost exactly on a cello C (2 octaves below middle C). That would make it about 65.5 Hz. Now that pitch is inaudible at any speed of zoom thanks to the SM3. But...

There's a new pitch appeared - the F at the bottom of the Bass staff (about 87 Hz). This appears ONLY at zoom speed 8, not at all below it, and very briefly when passing through zoom speed 8 in a variable zoom and very briefly at the start of zooms faster then 8. This appears the be the resonant frequency of my Matthews MN25 tripod with the A1 on top, because that's the pitch I get when I tap the end of the pan handle. Why this is triggered by the zoom motor at speed 8 I have no idea.

I'll need to see if this can be damped because it will be bad news if I'm filming a trombone or similar loud instrument and it suddenly goes kapow on that exact pitch.

Anyone else had probs with resonating tripods?

Doug Rose
January 17th, 2008, 08:25 PM
I'm just getting up to speep with xha1. When I plug my Rode nt1 in, and audio setup to xlr, then tap both mics gently, I see a level registering for both. so even if I see a level for the built in mic, should I assume it's not going to record form the built in mic?

Bill Busby
January 17th, 2008, 08:40 PM
You see those levels on both channels because you have the inputs switched to use both channels. When XLR is selected the builtin mic is disabled, so that's not what you're seeing.

Doug Rose
January 17th, 2008, 08:52 PM
ok thanks. I've set my rode to chan 1 and chan 1&2, and I swear I'm getting level from both mics, but it sounds like you know better than me. I didn't have my head phones handy, so I was just going off a visual.

Bill Busby
January 17th, 2008, 09:00 PM
Having it switched to CH. 1 & 2 is the culprit.

Disconnect the Rode & if you still get a level... well then I don't know what I'm talking about :D