You are here

Tape Hiss Emulation: White Gaussian vs White Uniform Noise?

For everything after the recording stage: hardware/software and how you use it.

Tape Hiss Emulation: White Gaussian vs White Uniform Noise?

Postby Uncle Freddie » Wed Jul 18, 2018 1:11 pm

Hi,

For several projects, I am incorporating a quiet track of stereo white noise to emulate "high quality" tape hiss.

By high quality I mean tape hiss from a properly calibrated pro open reel machine (in addition to noise from the console it would have been connected to) as opposed to a cassette deck.

I use iZotope RX6 to generate the white noise files; it offers several flavors of noise:

White Gaussian
White Uniform
White Triangular
White Binary

I know enough to know that White Triangular and White Binary are not useful in this case. So it comes down to White Gaussian vs White Uniform.

I created some 1 minute, -15dBFS RMS, 24bit, 96kHz files here:

http://substrate.com/whitenoise/rx6,noi ... df,01m.wav
http://substrate.com/whitenoise/rx6,noi ... df,01m.wav

(While these files are indeed loud, a project would use them at a much lower volume.)


FWIW, looking at Gaussian white noise on a goniometer, it is a more rounded blob, whereas Uniform white noise is a diamond blob:

http://substrate.com/whitenoise/white_gaussian.png
http://substrate.com/whitenoise/white_uniform.png

Finally, while I have to admit that they both sound fine, Gaussian sounds different from Uniform; I hear the difference clearly. In situations like this, I turn to science.

So, from a purely analytical, physical and magnetic standpoint: which one makes the correct impersonation of tape hiss?


Thanks,
Fred
Uncle Freddie
Poster
Posts: 25
Joined: Fri Apr 22, 2016 11:00 pm
Location: Detroit, USA

Re: Tape Hiss Emulation: White Gaussian vs White Uniform Noise?

Postby Hugh Robjohns » Wed Jul 18, 2018 1:30 pm

The different white noise descriptors relate to the probability distribution function properties of the noise signal, which becomes relevant if used for dithering. But in your situation, Gaussian is probably the best one to use.

However, genuine tape noise is actually a lot more complicated than simple 'constant' white noise because there are all kinds of noise modulation and filtering effects going on in a real tape machine.

H
User avatar
Hugh Robjohns
Moderator
Posts: 21680
Joined: Thu Jul 24, 2003 11:00 pm
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Tape Hiss Emulation: White Gaussian vs White Uniform Noise?

Postby Uncle Freddie » Wed Jul 18, 2018 7:09 pm

Thank you very much, Hugh.

-Fred
Uncle Freddie
Poster
Posts: 25
Joined: Fri Apr 22, 2016 11:00 pm
Location: Detroit, USA

Re: Tape Hiss Emulation: White Gaussian vs White Uniform Noise?

Postby James Perrett » Wed Jul 18, 2018 7:24 pm

Oddly enough I saw something about this a few days ago but can't find the link. The tape noise spectrum is dependent upon the speed and equalisation used and often contains more energy in the high midrange than a white noise signal. U-he's Satin tape emulator will generate noise and allows you to play with different eq settings.

If you don't mind short files I can probably dig out some noise excerpts from various tapes I've transferred.
User avatar
James Perrett
Moderator
Posts: 7484
Joined: Sun Sep 09, 2001 11:00 pm
Location: The wilds of Hampshire
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page

Re: Tape Hiss Emulation: White Gaussian vs White Uniform Noise?

Postby John Willett » Thu Jul 19, 2018 2:22 pm

Just makes me laugh - all those years trying to minimise all the the problems of hiss, modulation noise, wow, flutter, and all the other problems.

And when we *do* get rid of them - people want to put them backing again. :headbang:
User avatar
John Willett
Jedi Poster
Posts: 5414
Joined: Tue Mar 07, 2000 12:00 am
Location: Oxfordshire UK
John
Sound-Link ProAudio
Circle Sound Services
President - Federation Internationale des Chasseurs de Sons


Who is online

Users browsing this forum: No registered users