DEAFENING bursts of static on FCP

I just got blasted into sobriety! That was painful.

I had the Audio Mixer open at the time and saw that the meters were only spiking on tracks A4 & A5, which contained a 44.1kHz wav file. I'm going to convert the audio to 48kHz and pray that it doesn't happen again.

I'm editing on a MBP with FCP7. External speakers plugged into the headphone jacks. Airport is turned on.

I was able to replicate the bug by playing a certain part of the audio in the timeline. I turned down the volume to one notch above muting the system (it was still loud!) and tried to listen to what it was. It kind of sounded like it was picking up a cell phone conversation or a radio station or something.

Anyway, that's my contribution to the puzzle.
 
This has happened to me as well...
I think it's something to do with the audio output on the macbook pro..
I've only ever witnessed this when my external speakers, or headphones are plugged into the computer. Maybe it's some interference or something...
But, it doesn't happen with other programs, like itunes, or anything else that creates sound, which is bizzare.
I don't know...?
 
Not sure it has to do with the audio output on the macbook pro as this happened to me about 3 weeks ago on a mac pro. The only time Ive used the headphones when editing this year. There was some external building going on, so I threw the headphones on and brrsnnnnnnnp. I jumped a mile.
 
Haven't had this happen to me for awhile, but there is little more painful than this, ESPECIALLY with headphones on. And there is no warning, no indication that something will go wrong. I thought it had something to do with "rendered" audio, never source audio.
 
I had it happen on a live event I was working on...it rose people up out of their seats! Quite an embarrassment, for sure.
APPLE FAIL! What's up with this?
 
I opened up my macbook pro and found the problem:

gremlin_dog.jpg


Jason
 
Hi all. I registered just because of this issue. Not 20 minutes ago I was working in FCE on my 13" MBP at a coffee shop when this happened for the Nth time. When it first started happening in the summer I thought it was my headphones and I eventually ponied up $30 for a new set a couple months ago. But it's happened at least four times since then.

This time (after I had calmed down and assured the other patrons I wasn't having a seizure) I unplugged the headphones, turned the MacBook's speaker way down just in case, replayed the same snatch of audio and got the same burst of static. At least I did the first and second times I replayed it, but not the third or subsequent times. So it's not my headphones and seems to be how FCE is handling things ... sometimes. This has only happened to me during editing and I have not encountered it in outputted files, so I believe it's an audio rendering artifact.

This particular incident happened in the midst of a Cross Fade (0dB) audio transition on A3/4 (my background music track) as I was fading it out to silence. Here's an image of the timeline, with the moment I think it happened encircled.

staticburst.jpg


Note: That peak in the waveform is a character speaking and not a static burst, but they seemed to coincide during playback.

Here's the properties for my audio tracks.

A1: Left, 48.0 KHz, 16-bit Integer
A2: Right, 48.0 KHz, 16-bit Integer

A3: Left, 44.1 KHz, 32-bit Floating Point
A4: Right, 44.1 KHz, 32-bit Floating Point

Now I'm entirely self "taught" (if you can call my trial-and-error futzing around being taught) but in writing this post I can't help but wonder if any of these are causing the problem:


  1. The differing audio formats.
  2. The manipulation of same by the transition, which I may be using entirely wrong.
  3. The fact that A1/2 is a dialog track with patches of silence interrupted by a few words, while A3/4 is music with continuous sound.
  4. Any combination of the above.
So there's some more data for the puzzle. Thanks for reading.
 
Actually the answer is very simple. It is a sample rate mismatch. In an audio project all the sample rates need to be the same.
 
Jim_Behl said:
Actually the answer is very simple. It is a sample rate mismatch. In an audio project all the sample rates need to be the same.
Click to expand...

Maybe in some scenarios a mismatch *might* cause a problem, but I can say for me 99.9% of the time I am working with all 16bit 48khz files and it still happens. Ouch! Thankfully, I have not had it happen in over a month.


Jason
 
And here I thought I was the only one having this problem, except I usually don't monitor my work in FCP through headphones, but through regular monitors.

Has anyone reported this to Apple?
 
This deafening bust is not due to sampling rates and rendering does not solve the issue for me.

PLEASE contact me if anyone's found a solution!!!

OR if you want to sue apple for making you deaf

Thanks,
Orf
http://www.youtube.com/orf
 
DEAFENING burts of static on FCP

DEAFENING burts of static on FCP

We experience this, too, on an iMac, with or without mixed sample rates, with or without headphones, with or without footage from any specific camera. This is the type of sound that damages hearing and makes editing in FCP on the iMac very iffy. You never know when it's going to happen.

The only theory we have is that it may be associated with a render file?

Bradley
 
I have also experienced this glitch, running FCP 7 on a 10.6 Macbook Pro.
It has happened to me when editing footage from a variety of cameras, and with audio sources from a variety of sources, but always with their sampling rates matched to the sequence.
It's a serious problem that Apple should address with a patch.

I wanted to add my voice to the chorus of user calling for a fix, but I don't think there is anyone on these boards who is the "Jan Crittenden" of Apple.
 
As for this being a problem with the Macbook pro's headphone out, I have experienced the "static explosion" while monitoring audio through a USB interface.
 
sounds like a nice class action suit 2 me ... film it, get witnesses...collect proof...
luckily hasnt happened here yet.
I partook in 2 class action suits and won even though I was not living in usa, one was against apple and the other western union.
 
I already posted on this topic, but I thought any readers of this topic, may also want to look at a much larger discussion here:
<http://discussions.apple.com/message.jspa?messageID=11167727>

Bradley
 
Same bursts of deafening static

Same bursts of deafening static

Just had the same burst of frighteningly LOUD ear piercing static tear out of my speakers. I am running a 17 inch macbook pro, 10.6.6, FCP 7.0.3, I was editing a clip with 48khz audio from the Apple Final Cut Pro Training Series book, an audio file I am sure meets Apple's specifications and quality, yet randomly blasts the terrifying noise, happened twice to me today. Used to happen when I was running FCP 6 on my 20 inch Imac OS 10.4 and 10.5.

It doenst seem to be a matter of sample rate, type of machine, OS, or which version of Final Cut. and its not a matter of overheating as my processor is under 60C. It seems to be a FC problem. If anyone has any advice please post.
 
Every single time I've had this problem, it's been traceable to a mismatch between the sequence bitrate and the bitrate of some audio file in the sequence (usually a music or sound effect track).

To solve, first check your sequence settings, and make sure Audio -> Rate = 48 kHz. Then look through all sound files in the sequence (and, obviously, the sound in video files). To check them, open in Quicktime and look under format.

I almost guarantee you'll find some stray piece of audio that's set to 44000 Hz, 22050 Hz, or some other number that isn't 48000 Hz [note: 1 kHz = 1000 Hz].

So just open it in some audio editor (Soundtrack Pro works but is overkill, Quicktime Pro or the freeware program Switch are probably better), and export it as a 48000 Hz file.

And enjoy life!
 
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