Audio Popping/ Cracking???

ullanta said:
When the HVX had an audio problem reported by users, Panasonic was very responsive, determined a fix, and fixed all the cameras that had the issue. I'm sure that will be the case if there IS a problem with the HMC.

-Barry
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I hope that's the case this time, but let's be clear here. There IS an audio problem. I have had this issue with Mic ALC ON and OFF. With -50db AND -60db. I have NOT had it with an external mic only on camera mic. I will be doing testing as well. Here's one example with ALC ON audio level about half way -12db:

http://www.youtube.com/watch?v=zSPmCOXuJ4M
 
I haven't had any problems with the audio on my personal cam and the other one I use at work. And thats with the onboard mic and an external shotgun so I dunno if it a problem I am sure it will be addressed.
 
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First I've heard of this.

I've got a 150 and a 170 here right now. I'd like to try to replicate the issue. Can anyone suggest a step-by-step that will guaranteed cause the problem?
 
Barry is not on the case. I've never had any instance but hornet and others will be able to help. I've gotten great audio out of this thing.. and of course I just jinxed myself
 
Barry_Green said:
First I've heard of this.

I've got a 150 and a 170 here right now. I'd like to try to replicate the issue. Can anyone suggest a step-by-step that will guaranteed cause the problem?
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The time it happened to me, I was:

Using one XLR input to one channel, from house mix board.

Onboard mic on the other channel.

-50 setting

ALC = off

Recording musicians ( dualing piano players)

Meters hitting about half way, so no where near peaking
(-12 setting on the meters)

Would do the noise on transients, thought it was a bad mic cord, even though it was brand new, so chalked it up to that.

I will try to find the original track to see if it is in both channels or just the XLR board feed (the one with the xlr cable), others have stated this happens with on-board mics, only, as well.

Never heard it on any other footage, so the key may be a live event type footage that produces 120-130 db sound pressure level or so
 
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Barry, glad you're looking into this.

Typically when this happens I am recording a loud punk show with the on camera mic, ALC ON, levels set to around -12db, and audio set to -50db in camera.

I did some testing earlier today cranking up my stereo pretty loud and had no popping at all. I think this was because I simply could not get my stereo loud enough or close to the same level as a live show.

This is a pretty big concern for anyone filming live events such as concerts, wedding receptions, etc.
 
keentave said:
Barry, glad you're looking into this.

Typically when this happens I am recording a loud punk show with the on camera mic, ALC ON, levels set to around -12db, and audio set to -50db in camera.

I did some testing earlier today cranking up my stereo pretty loud and had no popping at all. I think this was because I simply could not get my stereo loud enough or close to the same level as a live show.

This is a pretty big concern for anyone filming live events such as concerts, wedding receptions, etc.
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Keentave:

The onboard mics are complete garbage and you could certainly expect poor performace from them in any loud environment, as their maximum SPL is not advertised, but would be expected to be low.

I don't think we should consider the reports of sound problems reported when using the on-board microphones. I don't want to sound harsh, but the on-board mics are of no more use than just being able to say it has on-board mics in the sales brochure.
 
Jeff9329,

Yeah I know the on board mic is not very good. I never use it for any serious recording. I have a shotgun mic for audio. With that being said, I also do know how an onboard mic is supposed to operate and have been filming concerts for many years now. My Sony Pd150 did not have this issue and my DVX100A on board mic also did not do this while recording live shows.

Also, there have been several other people saying they experienced this with external mics and coming from a board.
 
jeff: that's absurd.. however bad the onboard mics are, it should not pop! especially if the levels are kept in check.
 
question: what is suppose to happen when the audio level hits the limiter on the HMC? A smooth suppression of the audio? What if ALC is OFF? What do we expect to happen? I'm assuming the pop in these cases are not as designed?
 
I've had my camera for a four or five months, and every loud event (by loud i mean your ears would be ringing withing a few minutes) i have shot using the onboard mics has had the "popping" noise. ALC has always been on, not that it seems to do much. I figured it was just the crap onboard mic (and i normally stood/moved next to either the stage left or stage right PA stacks) and bass freq's not getting along well. Soundbooth helped out cleaning the audio a bit... When using two external mics, i haven't noticed the issue (they do have a built in limiter though, which i have never turned off).
 
but what is suppose to occur when the audio level peaks with ALC turned ON? Is it suppose to attenuate the levels so it drops off after peaking or are you expecting to get some pop/distortion? I think some people here are claiming that the pop occured even with no audio peaking?

I tested yesterday, I had my audio levels turned low so the levels never really peaked but I guess I can test again with the levels turned to max sensitivity and crank up the stereo, that will guarantee audio peaks right? Then what should I be expecting at that point?
 
booggerg2 said:
but what is suppose to occur when the audio level peaks with ALC turned ON? Is it suppose to attenuate the levels so it drops off after peaking or are you expecting to get some pop/distortion? I think some people here are claiming that the pop occured even with no audio peaking?

I tested yesterday, I had my audio levels turned low so the levels never really peaked but I guess I can test again with the levels turned to max sensitivity and crank up the stereo, that will guarantee audio peaks right? Then what should I be expecting at that point?
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What we are speaking of is audio distortion when the meters never reach the red zone.

You are implying that the reason is the sound is too loud and we are clipping due to us recording in the red zone (in the + db zone)

If that were the case, then ALL of the sound would be distorted, not just peaks, and the source would be full volume, not low volume.

We are stating that this happens at a lower average volume recording level
(between -18 db to -10 db AVERAGE recording level, with peaks around -3db)
This also seems to happen during high sound PRESSURE environments, like a live band, club, scene etc.

With ALC on, it should roll off your peaks to prevent this, if you were actually clipping due to reaching max headroom, I am thinking that because it never reaches the + db range, the ALC is not doing anything, however, the sound is still clipped at around -12db.
 
I recorded another live band Saturday night that I just got to review. Very annoyingly still there...despite levels so far down that the sound was barely audible!

Seeing most of the problem is focused on the onboard mic, my feeling is it is indeed not up to the task. As a "general, all around" mirophone it should BE at the very least, NOT DISTORTED!

Just thinking out load here, but:

It seems SPL (sound preesure levels) in the room are creating the clipping. It also is possible that the onboard mic head is physically sensitive and creating a "electro-mechanical" distortion. This is especially true for "very" sensitive condenser mics!

There is an electrial charge on the head surface of a condenser mic. If it is vibrating wildly do to high SPL's, guess what?! When recording a loud instrument (like an electric guitar amp) up close, a small head condenser mic is never used! It's usually a dynamic. Or a very head large, expensive condenser...AND NOT UP CLOSE I MIGHT ADD!!

In a recording studio, small head condensers are used for acoustic guitar, room, and cymbals (from more than a few feet away).

I was searching the net for some answers and found an article on the "Phoenix Systems" site. They invented a self monitoring audio system for optimum stereo sound. Guess what monitoring microphone they had trouble with SPL's...yup Panasonic! They have a workaround that is way more than we...or Panny would care about. But its a Panasonic electret condenser head, and interesting reading:

*excerpt: "When the cartridge is connected as described by Panasonic it produces fairly high distortion at moderate SPL's and is marginally suitable for serious recording and measurement purposes."

http://www.linkwitzlab.com/sys_test.htm#Mic
 
Ronedee, I agree that sounds about right what you're saying. That's a really interesting find, although a lot of that article is over my head as I don't have an extensive knowledge.

I do feel like this is something that Panasonic needs to address because my DVX100A did not have this issue as well as many other camcorders I have used.
 
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