View Full Version : Panasonic af100 clipping


Gary A. Smith
January 24th, 2015, 05:19 AM
Hi, i use the panasonic af100 at drag racing/burnout comps. I use the inbuilt mics but i am having trouble with the audio clipping. I adjust the levels manually but even when turning them up just past total cutoff i still get clipping occasionally when the cars are really close or extremely loud ones come out. I have alc on, which is what i thought stopped clipping but does not. Can anyone suggest anything please?

Thanks.

Gary in Australia....

Greg Miller
January 24th, 2015, 09:06 AM
An audio recorder (or the audio section of your camera) can clip in several different ways, at different points in the circuit. ALC can prevent some of those situations, but not all of them, as you have discovered.

I suspect the mic-level preamps are clipping. They are most likely located ahead of the ALC, which is why ALC doesn't solve the problem.

Some equipment has a "mic gain" or "mic sensitivity" control (*not* the same as a "recording level" control), or an input pad, to reduce the signal level going through the preamps. That's always a good place to start. The next option would be to use external mics, and then insert a pad between the mic and the camera's mic input jacks.

It is also possible for the mic itself (or its internal electronics, if it's a condenser mic) to clip. Of course once that happens, nothing you do in the camera can "un-clip" the audio. So if you decide to try external mics, be sure they're appropriate to your situation. A C-weighted sound level meter will give you some idea of the actual sound levels you're dealing with, then you compare the mic specs to that.

Rick Reineke
January 24th, 2015, 10:22 AM
Dynamic mics inherently can (normally) handle higher SPLs than condensers. I recorded some race car sounds a few years ago for S/FX and used Sennheiser 421s, Shure 57s as well as SM11s (Shure's dynamic lav) in the engine compartment.

Gary Nattrass
January 24th, 2015, 02:19 PM
It can be quite common on low cost cameras for the mic input or even the level potentiometer to overload.

I once had a "director" self shooing on a Sony Z1 and he had been feeding line level into the mic inputs from a mixer, he set the levels using tone and it all lined up Ok on the meters but the resulting audio was basically just overloading the mic inputs even though the levels on the meters looked correct.

It is always another reason to always monitor the audio as it is going into the camera and an external mic with some 10-20db pads may be the best option when recording high level audio, even better a mixer that has attenuators before the signal hits any part of the mixing part.

Some mic's actually have -10db pads fitted and this is usually in circuit before any of the electronics that may be on board, indeed the AKG 451 mic actually has screw on -10db pads that could be fitted in between the capsule and the mic body.

Gary A. Smith
February 1st, 2015, 03:55 AM
Well, i'm having real problems with the audio i have recorded. I am editing in Premiere Pro CS 6, i exported the audio into Audition to clean it up. I think i have clipping as well as CLICKING. I cannot seem to get rid of the noise. I can post a small sample to whoever would like to have a go at it and tell me HOW you did it. I would be EXTREMELY greatful for help on this. i have a total of around 12 hours of this rubbish to clean up as best i can. I will be looking at either recording next time with my little sony handicam (never EVER had a problem with it's audio) or buying a small digital recorder (zoom etc). I really like the method of exporting audio into Audition from PP as when you are finnished it updates PP with the edits. COOL. So, if anyone wants to put their hand up i can email it or maybe post it here somewhere?

Thank You

Gary Smith.

Les Wilson
February 1st, 2015, 07:15 AM
I can't speak for the Zoom (which was originally designed for guitars but may have caught up to professional recording needs) but the Tascam DR-40 has a feature that lets you make a backup recording at a different gain level. That is, you end up with 2 stereo recordings. So while you may use your primary recording for most moments, the times it overloads, you have the backup recording taken at a lower level. The DR-40 also works with line level as well as mic inputs when you want an external mics. And the built-in mics aren't bad; definitely better than your camera's.

Don Palomaki
February 1st, 2015, 07:50 AM
[quote]I really like the method of exporting audio into Audition from PP as when you are finnished it updates PP with the edits. COOL.[\quote]

Once upon a time Audition was known as COOL EDIT PRO (before Adobe bought it)
It includes an audio restoration filter that reduces the effects of clipping - it might help.
How To Fix Distorted Audio In Adobe Audition (Clipped Audio) - YouTube

Rick Reineke
February 1st, 2015, 10:32 AM
Many of the budget clip restoration plug-ins ("usually included with the host software") work OK for some minor digital overflows, but do little to restore analog clips, either from the mic itself and/or preamps... so YMMV.
If a sound clip is posted, we can likely recommend a strategy

Gary A. Smith
February 1st, 2015, 05:45 PM
For some reason i can't post the attachment, i have put it in my dropbox, here is the link to access it. Hope it works, never tried this before: https://www.dropbox.com/s/3y2qpwvktjj1z1c/Car%20Clipping.wav?dl=0

Rick Reineke
February 2nd, 2015, 09:37 AM
Yeah, the download works Gary. Don't have time to listen right now though.
Later: Sounds like microphone and/or preamp clipping, The best way I found to minimize it with what I have at the moment on my laptop; Sound Forge Pro with the 'Click/Crackle' removal plug-in.
BTW, the attachment file types are very limited on here. no WAVE or MP3

Gary A. Smith
February 2nd, 2015, 08:10 PM
Thanks Rick. I used the Audition remove click and remove clip tools but didn't do much but that was just on the default values.

Rick Reineke
February 3rd, 2015, 08:44 AM
Haven't used 'Audition' since it was Cool Edit Pro.. in any case, most all 'factory' presets need to be tweaked, as was the case with the Click and Crackle removal tool. (a plug-in from the SCS Noise Reduction 2.0 suite) which generally works ok. If I had iZotope's RX installed, I would have used that, which is superior to NR-2.0 IMO. (and more expensive)..