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What's wrong with this audio?

I recorded production audio while shooting for someone else's shortfilm. She got back to me, and said that there is one section of the shoot where all the takes have a high squeeling sound on it. There is no usable takes for this part of the scene. She says that it's not acoustic and that it's definitely a technical problem on the equipment it sounds like. Here's one of the takes, which is the line she needs. However, I cannot hear any squeeling sound.

We tried a test. I sent a copy of mine too her, since I had an extra copy, she played it back on her speakers, and then said it was the same. She sent it back to me, and I played them through mine to see if anything has changed but it sounds the same as it does now. She tried it in different media players as well, and it also sounds like it's squeeling in her editor as well she said. Can you hear anything, perhaps it takes special speakers to hear it?

https://soundcloud.com/harmonica44/9a28eeba-930a-4f11-b33a-eb47d5feb9c71

Thanks.
 
It's impossible to do anything other than guess at what the problem is without knowing a lot of things about how she's handling and listening to the audio - but harmonica, the clip you've posted at least demonstrates it's not an inherent problem in the recording itself.
 
If there is a consistent high squeal, wouldn't you able to see it in a spectrogram? Maybe pull up a spectrogram on it to take the whole speaker thing out of the equation?

I think you would see a solid line in the upper range showing a clear hum/squeal. Take a screenshot of the image if it shows no signs of a squeal.

I am definitely no expert though.
 
I am new to this, and just getting the hang of recording it. Even the recording could have been better possibly. But the character is in the background of the scene, so him sounding further away helps anyway it seems.

I am not good at readng spectrograms but I am not seeing solid line at all, such as what you described. Do you mean the blue line, when you access the noise reduction feature, or something on the actual spectrogram?
 
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No "high squealing sound" that I can hear.


Now, it is possible that her system and/or room is overly hyping something. Have her over to your place, or you go to her place for a "listening party."


Another option - she might have tinnitus, temporary or permanent. She get into a quiet room, listens to the audio and hears the ringing in her own ears.


Of course, some people just look for something to bitch about, even if it isn't there.
 
Can't really hear noise when the audio you posted is solid dialogue.. it's also possible that if it's a high enough frequency some compression somewhere cropped the frequency out.

Anyway, without hearing quiet parts of the recording too it's really not as easy to pick out noise
 
Okay thanks. She says it's only during this section of the scen though. All the guys lines were done in the master only, so he's in the background. His section of dialogue there, was not recorded in any other shots. It is during the master shot takes, that this squealing is present she said.

All the other shots in the movie are okay, sound wise. So it probably is not tinnitus I'm guessing. She wants to have it on DVD by a certain time, and I don't think I will be able to book time off to work, to come see her, be able to see her the next day, off since she lives a few hours away, so I cannot listen to it with her directly, on her computer or mine. I can just listen to the files I have, plus the ones she sends me, but they sound the same as the original takes I have on my computer.
 
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it sounds to me like it's entirely her problem - none of us have heard a single thing that sounds like high pitched squealing (tell her to listen to it on a different computer. have your friends listen to it and see what they think)
 
I can't actually download the file to analyse it in detail but just from listening, it's obvious that there is a huge amount of energy concentrated in the very low frequency range! At a guess I would say that the 20Hz - 30Hz range contains roughly 10 times (20dB) more energy than anywhere else in the frequency spectrum. This is certainly a possible cause of the issue you describe.

The problem is that how a specific speaker system deals with a very high concentration of energy in the very low freqs is highly unpredictable. A theatrical sound system would reproduce those frequencies and you would hear quiet dialogue with a loud rumble. Consumer and even professional studio monitors would not be able to reproduce those low freqs and all you would hear is quiet dialogue. It would therefore would be natural to raise the output level of that dialogue but of course that would also increase the output level of that low freq energy (which you still wouldn't be able to hear) and this is where we're likely to run into issues. It's entirely likely that the overall energy level of this audio clip could be at or near the overload limit of the speakers or the amp (even though it doesn't sound loud). What happens when one runs speakers/amps at or near their limits varies according to their design but a phenomena known as InterModulation Distortion (IMD) is common and could easily sound just like a "squeal".

The obvious thing to try would be a steep High Pass Filter (say -24dB/8ve) at about 80Hz and see if that stops the squealing.

She's editing the audio herself ...

She patently isn't otherwise she'd have noticed straight away the high concentration of energy in the low freqs! If she is going to try and edit the audio herself she is going to need some appropriate audio editing equipment and some audio editing knowledge or she needs to find someone who does. This is just one of countless audio problems she is likely to encounter and many of them she probably won't even notice until it's too late. BTW, you should have noticed this issue as well. Better still, you shouldn't have recorded it like that in the first place!

G
 
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Okay thanks. For next time when I record, how do I avoid huge energy in the low frequency range?

Also, I figured out PART of the problem. I listened to it on her computer tonight while helping with her editing. Her friends all agree that they could hear the unwanted squealing, but that's because she played it back for them on her computer. Here's something I've noticed. It's not a sqealing sound but more of a ringing sound, and I have heard this exact sound before. When I import audio tracks into Adobe Audition, it sometimes plays back certain tracks with the exact same ringing sound.

The track does not playback with that ringing sound on my speakers, or on soundcloud, since you all cannot hear it you say. However, when I play it back through Adobe Audition on my computer, it gives the exact same ringing sound she has on her computer So her speakers play it back like how Audition does, with the ringing. Does this help ascertain the problem at all, as to what it could be?

Thanks.
 
For next time when I record, how do I avoid huge energy in the low frequency range?

1. Make sure you have headphones which can reproduce low freqs, so identifying the problem is at least possible to start with.
2. Listen/monitor carefully and make sure you actually notice what's going on in the low freqs.
3. If you are getting some sort of rumble, identify what's causing it.
4. Avoid what you've identified is causing it!

Rumble is usually caused by some sort of vibration travelling through the mic casing via the boom, stand, cable or whatever else the mic is touching, alternatively it could be caused by some air movement hitting the mic's capsule (wind for example). In this particular case it sounds more like the former, some sort of handling noise, so for starters look at the shock-mount, the cable and how you are handling the boom.

So her speakers play it back like how Audition does, with the ringing. Does this help ascertain the problem at all, as to what it could be?

Not really. If it's a ringing, it could be some sort of clocking/sample rate/phase related issue but I don't have much experience of Audition. Although ringing isn't generally a symptom of IMD, you/she will still need to deal with that excessive low freq energy.

G
 
Okay thanks. I did some tests with the shockmount but it seems pretty solid and non-moving, no noise seems to be coming from it. It could be the boom as I just do what some others do and just using a painters pole, and customizing it into a boom, but I want to get a real boom later, as the pole is not the best. I also used a blimp when I recorded, so I don't see wind being the issue. But who knows. I will pay more attention to it for next time. Does this rumbling run across the whole track or just parts of it?
 
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She's editing the audio herself...

We all know how easy it is to do audio post; it's just sound, right? You can't see it, so how hard can it be? And who needs real speakers or a treated room? Completely unnecessary, since the audience isn't listening on nice speakers or in a treated room, so the speakers and the room just can't have any import whatsoever.
 
Well her speakers are a lot worse than mine since she is using laptop speakers. Not external speakers but the speakers that came with the laptop.

I had a similar experience way back when I hired an audio engineer. The short film sounded great on her good speakers but crappy on other people's average ones. So if crappy speakers bring out the worst in sound, how am I suppose to tell if good speakers make it sound better than how the average viewer is going to hear it.

Since most people nowadays watch movies on the speaker that come with their computer and TVs, and it seems that 30 percent of people I know, watch movies on their phones a lot. Of course it's good to listen to your audio on good speakers, but if I can't hear the audio flaws that are being brought to me, compared to other people's systems, than perhaps I need different speakers, perhaps not bad speakers but even more good ones.

However, the movie is giving off the same ringing noise that you get when you play it in Adobe Audition so it is just the way it's played media wise, perhaps? Perhaps certain types of media playing will bring out the worst in audio compared to better, but that's just a guess and still haven't figured it out.

I won't stress or spend too much time on it since it's her project, but it's good to know for later, as it could happen on one of mine in the future.
 
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