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Gear / Technical Help => Ask The Tapers => Topic started by: Elguapo511 on October 07, 2019, 10:53:56 AM

Title: Why does my .wav look like this? (Stealth content)
Post by: Elguapo511 on October 07, 2019, 10:53:56 AM
I recorded a crazy loud metal band called oozing wound.

The stealth mics were in a headband just in front of my ears.

Any reason why the file looks flat on the the top?

I was using cafs and a 12v battery box.
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: ilduclo on October 07, 2019, 11:09:24 AM
hows it sound? looks to me like just a display issue, I can get a wav to look like that by moving a vertical slider offa the zero mark (center axis of the wav file)
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: Elguapo511 on October 07, 2019, 11:15:03 AM
its sounds fine.  Nothing noticeably missing.  It was very very loud so, a bit herd to hear detail.  I am just glad it was not distorted.


Does this have anything to do with the mics placement.  it thought this would give it more stereo if my skull was in the way.

They were flat to my head.  Do they need to poke out?
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: ilduclo on October 07, 2019, 11:17:09 AM
If it sounds fine, that's the deal we're looking for, remember, it's audio!! :bigsmile:
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: TheMetalist on October 07, 2019, 11:20:47 AM
Not sure what recorder you use but did you have the Limiter setting on?
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: Gutbucket on October 07, 2019, 11:43:16 AM
Its an asymmetrical waveform, which has been limited, clipped or highly compressed on the positive-going side of the waveform more-so than the negative-going side.

Might be due to insufficient mic powering or overload occurring somewhere in the signal chain.

If it sounds okay you probably don't need to worry about it, but if there is significant DC offset you might want to correct it.  DC offset eats up headroom in your output file compared to a file without DC-offset, which isn't really a problem unless you are normalizing or attempting to maximize the loudness of your finished output.  If DC offset is significant enough it can stress the amplifier and voice-coil of the speakers because current will be flowing to hold the cone still in that offset center position even when the speaker is supposed to be at rest and not moving in either direction due to the music input signal.
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: ThePiedPiper on October 07, 2019, 01:15:41 PM
Its an asymmetrical waveform, which has been limited, clipped or highly compressed on the positive-going side of the waveform more-so than the negative-going side.

Might be due to insufficient mic powering or overload occurring somewhere in the signal chain.

If it sounds okay you probably don't need to worry about it, but if there is significant DC offset you might want to correct it.  DC offset eats up headroom in your output file compared to a file without DC-offset, which isn't really a problem unless you are normalizing or attempting to maximize the loudness of your finished output.  If DC offset is significant enough it can stress the amplifier and voice-coil of the speakers because current will be flowing to hold the cone still in that offset center position even when the speaker is supposed to be at rest and not moving in either direction due to the music input signal.

Gutbucket to the rescue. I love reading and learning from him. If I was in Vegas, and a betting man, I would put all my money on his answer.

This might help as well if you use Adobe Audition:

https://taperssection.com/index.php?topic=182744.msg2232880#msg2232880
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: Gutbucket on October 07, 2019, 03:12:23 PM
Well that's what it looks to be, based on the photo of the waveform.  The cause of it is an educated guess, based on having come across similar instances. 
Thanks for the kind words.


Heh, Oozing Wound. That's a name which certainly sets a tone!
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: SxPxDxCx on October 07, 2019, 03:14:25 PM
Love Oozing Wound.  Are you going to be sharing this?
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: Ziggz on October 07, 2019, 03:47:22 PM
I can't find the post, but Chris Church said not to use a 12v bb for CAFS as it would fry them.
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: ThePiedPiper on October 07, 2019, 03:53:42 PM
I can't find the post, but Chris Church said not to use a 12v bb for CAFS as it would fry them.

I've looked for it as well and I do recall him saying that 9v it the max power for the CAFS. I think you are correct.
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: Gutbucket on October 07, 2019, 04:14:43 PM
Might be due to insufficient mic power or overload occurring somewhere in the signal chain.

Edit^.  Better to term it improper mic powering rather than insufficient mic power in that case.
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: ilduclo on October 07, 2019, 04:32:11 PM
post it in kickdown! :laugh:
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: daspyknows on October 08, 2019, 01:45:55 AM
its sounds fine.  Nothing noticeably missing.  It was very very loud so, a bit herd to hear detail.  I am just glad it was not distorted.


Does this have anything to do with the mics placement.  it thought this would give it more stereo if my skull was in the way.

They were flat to my head.  Do they need to poke out?

I run my Schoeps MK4/41 right above my ears. 
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: lpmaskman on October 12, 2019, 05:41:54 AM
DC offset?
Title: Re: Why does my .wav look like this? (Stealth content)
Post by: Ben Turnbull on October 12, 2019, 02:35:43 PM
I was going to say that that's a classic representation of the "Head Band Effect" but got to the party so late that it's lost it's punch...  :yack:

Maybe post a link to a couple of minutes of this to see if others show the same wav form? A thought.