What's wrong with my unbalanced audio wave?

[colinmcgray]

Hi folks,

I had a wee question and would appreciate any help you could offer.

I'm recording a Podcast with the following setup:

MXL990 microphone > Behringer Eurorack UB1204FX Pro > Zoom H4n

I record myself and a cohost on separate microphones, and output them on separate tracks into the H4n, so I have me on the left and co-host on the right. I then split those tracks to mono to do my post production.

I'm finding, though, that my waveform has a funny look - it seems unbalanced vertically, ie. It reaches further into the negative than the positive. Probably much easier to see in a picture, so I've attached an example.

The track sounds OK to my un-expert ear, but I do find sometimes that it can be lost a little when I place it over a backing track. Then when I amplify the voice to try and bring it out, obviously the top end of the wave (the +) doesn't get close to the max. Could this be why?

I suppose my question is, is this showing a problem in my recording somehow? And if so, any tips on how to fix it?

Any help much appreciated!
Colin

[flynwill]

Indeed it does look suspicious. Can you post a sample of the original stereo wav file?
I would also suggest zooming WAY into the waveform and having a look. Might be your
microphone pre-amp is breaking into oscillation.

[colinmcgray]

Thanks for the offer of help - happy to post a sample.

I've also zoomed in to have a look but I'm not sure exaclty what I'm looking for. I'll attach that image too incase that helps.

Thanks,
Colin

[colinmcgray]

And here's the audio sample - thanks again for looking!

I've had to make it very short to fit under the upload limits, but hopefully should let you hear the quality. This was of a section that looked very unbalanced in the wave view.

[steve]

Strange as it looks, I don't think there is a problem.
It's not unusual for voices to look "unbalanced", though your example is more pronounced than most. The phenomena is also common with brass instruments.
The important thing is that the "average" value is centred around zero, which yours is (almost perfect).

To demonstrate that the average is zero, apply the Normalize effect (Effect menu) with only the "Remove DC offset" enabled. You should see .... nothing. If the waveform is correctly centred around zero, the DC offset correction will do nothing.

Where does the low-cut filter come into the picture?

[kozikowski]

You have a non-symmetrical voice. I recorded a woman/man broadcast radio show and I could pick out who was talking totally by looking at the blue waves. She had non-symmetrical wave and he didn't. It's possible that anything we do to "fix" that may make you sound funny.

We can make something up if you want, but I'm with the "normal" crowd. And yes, it will throw off your tools that need wave tip measurements.

If it makes you feel any better, swap microphones and I bet the effect stays with you.

Koz

[flynwill]

Looking at the waveforms I agree. Your voice is oddly asymmetric, but there is no evidence of any electronic problem.

[colinmcgray]

Thanks for the feedback guys - that's really useful, and definitely reassuring!

To follow-up, I've done a little experimenting, and discovered, based on your suggestion, that the low-pass filter does seem to have an effect on it. I really don't hear a difference in my recordings when I use the low-pass filter, but it completely changes how the waveform appears on-screen by shifting it probably about 20% upwards on the waveform axis. Very strange.

Anyway, thanks for reassuring me that I'm not missing some really obvious equipment malfunction or similar!

[kozikowski]

I really don't hear a difference in my recordings

Listening on what? built-ins and most "computer speakers" do not play good quality sound. Good headphones or a very good sound system is required when you start Quality Controlling your voice.

What are the Low Pass Filter settings? It's very easy to muffle your voice with that by accident. Are you hundreds of years old? Old Ears start peeling off those crisp, sparkly high sounds.

I can understand the High Pass Filter affecting that. Subsonics caused by a rumbly voice.

Koz

[kozikowski]

If you do have a rumbly, professional, reassuring voice, why are you complaining again?
Koz