Audio Frustration!!
 

So I finally made my first shot this morning in Chicago by the lake Michigan, where you can see the whole downtown and everything was great. I used Steven’s preset “vividRGB”(thank you again for that one!) and I also had all the time the shotgun Audiotechnica AT897 with this kit http://www.bhphotovideo.com/bnh/cont...ist&sku=481529
I contented it to XLR channel 1 and then set CH1 and CH2 so I would have stereo image (of course in audio menu I set the XLR out) and everything seemed to work great. Only I did not have headphones to monitor the sound, but I pretty much controlled it through the display controllers.
What a UNBELIVABLE SURPRISE! When I played back the movie on my TV at home. There was a radio station 97.1 playing in the background of my audio the whole time I was recording and it was very clear, loud and my whole audio footage was messed up! I never thought this could happen and I really need some advice what to do with it.
Did anyone experienced something like that?
Doe’s that mean, that I can not use shotgun in the big towns where is a strong radio signal?
Next time I will bring my headphones to hear what I am recording, but what am I supposed to do, if I hear radio station playing through my mic?......it was there all the time even if I changed location or tilt the camera up or down…….sometimes it was very clear and sometimes weaker, but the audio is now unusable.
Please any comment and solutions very appreciated
Thank you
Roman

This was my setup:

I haven't run across that one in a long time, but a number of years ago I was shooting on the top floor of a building too close to the most powerful radio transmitter in town. I could hear the station in my headphones.

What we did was, first, minimize the cable run, and that cut it down but not out. Then we shielded the audio cable with aluminum foil, and that did it.

With a mic on the camera I'm not sure what you could do except move to a different spot. Were you shooting across the lake from the aquarium? I've shot from there and had no radio interference, Sony short shotgun mic on the camera for getting ambient sfx.

First of all, you will not get a stereo image with this mic. It's a mono mic that when you throw the ch 1, ch 2 switch on the camera, you will get the exact same track on channel 1 as you will on channel 2.

Concerning your FM reception issues, are you using a battery in the mic or are you using phantom power from the camera? If you are using the battery in the mic, try using the phantom power instead. You will get a better signal that way and perhaps fix your problem at the same time (a stretch...but it won't hurt to try). The next step is to ensure that your cable from you mic to the camera is in tip-top shape and there is pin-to-pin continuity with no surprises.

If neither of these get it done, you are going to have to narrow down what component is transferring the RF into your camera. 9 times out of 10 in this modern age, it is a faulty component.

Good luck!

You mean you can pick up a radio station in a non-wireless mic as well?

Or is it a situation where Roman didn't hear it, but the mic was picking it up louder and recording it?

You almost need a checklist for equipment and settings before heading out. Like someone mentioned here before, the pilot's checklist.

Trish

Thank you all for useful comments!

Bill, I was across the planetarium, which is a little way from Aquarium and I believe there must be a powerful radio transmitter:)

Robert, thank you for clarifying the mono/stereo issue……you are right, I did express my self not the right way……….
That is a great advice from you NOT using the inside shotgun battery and set the phantom power in camera to on (I belive it is the XLR gain up + 12db in audio setup?) I thing that would resolve the issue and I did know that this way I would have better signal also! I will definitely try that next time on the same spot..... The cable I have from cam to XLR is brand new and looks like in good shape, but you never know, so that would be an option to change it too. Later I was shooting in Chicago downtown and had no problem at all.

Trish I really picked up a radio station (97.1) on my non wireless mic and I could not believe it is happening. The signal was so strong, that it was like you are listening a radio station in your car and it was not there when I was shooting....... It was really bad surprise to find that out when I played it on my TV.

But I am still trying and learning to get best from the camera and your help mean a lot to me, thank you again all!

Roman

I found it. It is on the back of the XLR inputs : fantom power on off.........and I don't have to put a battery to the shot gun mic...GREAT!

Phantom power increases the maximum sound pressure level before excessive distortion with many of the AT mics, so it is usually good to use it.

RF pick-up is often caused by a cold solder joint, or overloading a transistor junction, and can be facilitated by poor or open shielding. I was not clear as to whether or not you used the +12 dB audio gain-up, but if possible, avoid using it. That could increase the likelihood of RF pick-up.

Next time, carry a different mic with you as well to see if it is effected by the RF. And check if phantom vs. battery power makes an difference.

As to trying to salvage the audio, if the level is down low enough, you might be able to suppress it somewhat with some using a noise gate for quiet portions, selective filtering if the sound of interest is mainly dialog, and masking it with hiss/white/city street background noises.

I finally looked at the photo with the mic mounted on the camera. Obviously he would have been recording only ambient effects, so in that case it might be best to just use the in-camera mic. It's not all that bad if you just need traffic noise, etc.

Modify the rig
 

Just a note, as I'm using the same camera and mic combo:
1. invest in a 'dead-cat' furry windscreen (preferably one that fits over the stock foam windscreen). It will take out a measurable amount of wind noise.
2. If you are using a hot-shoe mic mount (which is fine), but need to use a hot-shoe accessory in the future, I would recommend taking the AT-897 shotgun and fitting it into the Canon's stock auxillary mic holder, with foam padding (or soft rubber padding) to make up for the small diameter difference.
3. Carry a set of portable earphones with passive noise cancellation (silicone rubber earcups that fit entirely in the ear). This works wonders in noisy environments (especially near bands and dj's when you want to concentrate on the recorded sound). I bought a Creative Labs pair for $35 and they rock!

I dissagree with suggestion #2. The mount he has will do a better job isolation/preventing camera nise to the mic that putting in to the stick mic holder which s not shock mounted at all.

The stock mic holder on the A1 contains some isolation padding, just not a lot. It is most effective if the mic is not clamped down tight, but fairly loose.

Orien

Could you tell me the name/model of the sound isolation earphones you referred to from creative labs and where purchased.

I have been using racing headphones (cut off the mono plug) over the top of earbuds.

Thanks,

Bill in Ohio

Hey Roman,

Nice setup! I have a very similar setup to you, only it's a rode shotgun mic. Could you help me out and show me the exact XLR cable you got for your shotgun mic in the picture you posted? My XLR cable is a bit longer than your's it seems and I'd love to tighten it all up. Any help is greatly appreciated. Thanks.

good info
 

In this thread for me as I use a similar setup.

#1 lesson learend - Always use headphones.

I havn't screwed that one up for a long time, but I've tempted fate a couple times recently. Good reminder.