mic/sound input levels

joejon wrote on 8/25/2006, 1:37 PM
Before using an external mic I never had audio clipping. Using the AT822 I would get some clipping, even when being quite a distance from the band. I no longer have the AT822 and I'm looking at getting the new Rode Stereo Videomic. I'm assuming that I will have the same clipping problems since they have similar specs. Any suggestions to deal with the clipping without having to have an elaborate sound setup? I don't have the luxury of testing the level of the sound/music before hand. I would like to be able to move in closer to cut out a lot of the audience noise, but then I get more clipping. I've found that using the Clipping Restoration function with Noise Reduction works fine at times, but sometimes can add some strange noises and pops to the audio, so I'd rather not have to use that.

Comments

richard-courtney wrote on 8/26/2006, 12:22 PM
You need to determine if the sound pressure is too much for the mic.
Use a handheld meter.

If it is then increase distance or select a mic that can handle the sound.
If not, then you can try padding the input with a plug in pad. The rode SVM
has a built in 10dB pad.

http://www.rodemic.com/downloads/MicSpecs/SVM.pdf

http://www.m-audio.com/products/en_us/MicroTrack10dBPad-main.html
joejon wrote on 8/26/2006, 1:50 PM
Where most of the band concerts are held I'm already at the back, so I can't move any further. I see that the SVM does have a pad, like you mentioned. I've been trying to find info. on the web what exactly that is and what it does, but I haven't found much. I know it has something to do with lowering the sound, but I'm not sure exactly how and also when I should use it. As with concert band music, the volume changes a lot from very loud to very soft, so I don't know if it would be good to leave the pad on. My other mic only had a high pass filter, which I never used (AT822). If you have any info. or a link I could go to please let me know. Also, do you know much about the Rode SVM? I'm debating whether to just get another AT822 or try the Rode model.
rraud wrote on 8/28/2006, 2:14 PM
Your problem is most likely with the soundcard and/or mic preamp settings.. not the mic or software
More info on your set-up would make it easier to suggest fixes.
Specify your signal chain and settings, soundcard, ect.
richard-courtney wrote on 8/29/2006, 1:57 PM
The pad lowers the signal level coming out of the mic. If too much signal is going into your recorder (camcorder?) it will clip. Are there any settings for automatic level
control or gain adjustments?
Tell us your recorder model if you don't mind so we might help more.
joejon wrote on 8/29/2006, 8:35 PM
My video camera is a Sony Digital8 model TRV-340. I don't believe there is any kind of sound adjustments I can do; that's probably on higher end cameras. My computer sound card is a Sound Blaster Audigy, which is the same one I used before I used an external mic and didn't get the clipping. Maybe because the external mics are more sensitive and pick up higher levels of sound it's easier to 'overload' the cameras sound system resulting in clipping. (That may be stupid, but I'm just trying to think of what is happening). I don't know if the distortion/clipping is actually recorded on to the tape or if it is only when I capture it into Vegas and also open in Sound Forge. I don't really hear distorted sound when I just play the tape, but that doesn't mean that there isn't any. And if you have any thoughts on the new Rode Stereo Videomic or the AT822 please share your opinions with me since I plan on getting a new mic soon. Thanks for your help.
farss wrote on 8/30/2006, 12:56 AM
OK,
I don't think any of the D8 cameras have manual gain control or any way to turn off the AGC so you're kind of stuck with the camera the way it is.

Now a question. When you look at the waveform in Vegas or SF does it have really flat tops?

See one of two thing might be happening here.

Maybe the mics overloading, you didn't say what sort of band, if we're talking heavy metal then it might be quite easy to overload some mics. If that's the case then typically you'll get more rounded tops to the clipping. If the mic is overloading (which is probably unlikely) then you just need to use a different mic.

If they've got really flat tops then it is digital clipping. Best solution then is a pad, probably try 10dB although you might need more. The one someone suggested from M-Audio would probably do or else if you're handy with a soldering iron not that hard to roll your own. I recall seeing a few DIY minipin pads on the web, try a Google.

Unfortunately though your biggest limitation is the audio section in the camera, the AGC circuits are not designed to cope with the huge dynamic range of what you're recording. Any recording device that lets you turn off the AGC is going to give you better results.

Bob.
richard-courtney wrote on 8/30/2006, 5:17 AM
Can you plug in a good pair of headphones (not ear buds) into your 340?
Don't trust the tiny speaker on the side of the camcorder.
If it sounds distorted there, you will need to try the pad.

If it sounds OK in the headphones on the camcorder playback, then make sure
you aren't boosting the track in Vegas or Sound Forge. Turn off all
processing as there are gain settings in almost all the plugins.

Since you don't have the AT822 anymore I guess your best solution is to go
with the Rode. Purchase the pad just in case you need 20dB (10 from the
built-in and 10 more from the plug-in). Hopefully you can try a test before
the event when the band is warming up or setting up the day/night before.

There are devices with XLR inputs, adjustment controls, and a meter.
Beachtek DVA-6VU for example. With mics will be priced over the camcorder's value.

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=418508&is=REG&addedTroughType=categoryNavigation

That is about the limit of my suggestions, good luck.