Fine Lines of Noise - Spectral Frequency Display

Report · Apr 11, 2017

Hey guys,

I am hoping I can get a little help identifying some noise that is being introduced in an initial recording.

I record VO predominantly and in the last few recordings I have noticed some fine lines of noise in the spectral frequency display. The lines are only noticeable when zoomed right into the timeline. This noise is very sporadic and not in every recording nor is it throughout a recording it is usually just a specific sentence. In saying that when the sentence is recorded again the noise is not there.

As I have never seen this before I would like to know if someone has had this happen and what the cause may be. What would you suggest as troubleshooting steps.

I have had a little issue in the past with .WAV corruption but this seems like an altogether different issue.

Please see the attached screen shot.

Thanks for your time.

Liam

Report · Apr 11, 2017

If they were lines of actual 'noise', they'd show horizontally, not vertically. They look far more like mini bursts of interference of some kind, or caused by a minor overload. Can you zoom in one and show a screenshot of that, and can you provide a small audio sample?

Report · Apr 11, 2017

Hi Steve,

Thanks for your reply. I have zoomed into the area of noise (please let me know if far enough) please see below.

What is the best way to upload a sound file to here?

Thanks

Liam

Report · Apr 12, 2017

That definitely looks more like interference of some sort. The way that most people find that works in terms of uploading a file is to put it into a public folder in Dropbox, right-click on it, get the public link, and post that here, The one thing I'd say about this though is that it should be an uncompressed copy of part of the original - not an MP3. A few seconds will do - an undisturbed bit with the disturbance in it.

Report · Apr 17, 2017

Thanks Steve,

Apologies for the late reply I forgot it was Easter! I was initially looking for somewhere to attach it via the forum and completely didn't consider dropbox.

The link below is for google drive (I don't have DB).

RAW_Interference.wav - Google Drive

Please let me know that it works.

Thanks

Liam

Report · Apr 18, 2017

Yes it works fine, and it's certainly a little weird. I've heard similar noises to this come from a faulty microphone...

So just as an initial experiment, can you try a recording with the same chain of equipment, and a different mic?

Report · Apr 18, 2017

+1 for what Steve said about a microphone fault. Indeed, I'll go a bit farther and say that I've actually had a similar issue and, in my case, it turned out the condenser mic I was using had been stored in a damp area and the diaphragm needed to be dried out.

Report · Apr 18, 2017

Very interesting Steve. I certainly can. The only other microphone I have is a USB blue yeti. I'm unable to record for the rest of this week but will test next week if you can bare with me.

Also very interesting Bob as this is the microphone I have - AT2035 Cardioid Condenser Microphone || Audio-Technica US and I live in tropical Queensland and we've just come out of a pretty brutal humid summer. EDIT: Could this have been caused by a VO artist too? I do have a pop filter over the mic but admittedly i'm not in the recording booth and no direct vision of them. Not blaming them of course but just curious.

How would you recommend the mic to be dried out? I can do this in the mean time.

Thanks again for your help guys I feel like i'm making some progress on this!

Report · Apr 18, 2017

When this has happened in the past, I've dried mics out simply by putting them above a convection radiator for a while. It also helps a lot if you store them correctly - I suppose ideally in an airtight container, but it should also contain a sachet of silica gel. This will absorb any moisture inside the container, but this will only work really effectively if no moist air can get in. You can always tell if it has, because the silica gel will go pink. If this happens, put it on a tray and leave it in a domestic oven on its lowest setting overnight. This will drive the moisture that it has absorbed off, and then you can use it again. Sort-of a gift that just goes on giving! Don't put the mic in the oven though - that's not a particularly good idea at all. If you need it to work in a hurry, then wafting it gently with a hairdryer may speed up the recovery process, but I wouldn't bank on it. What you are trying to do is drive moisture out of an extremely constrained place between the mic diaphragm and polarising plate, and it's having to exit via the equalisation tube, which is pretty narrow - which is generally why it takes some time to achieve.

As for a VO artiste actually causing this - not impossible, but more likely that using it near a human was just the final straw.