Quick, simple question about Dynamic Range

[ubik]

Hello.

I've read many different definitions of the term "Dynamic Range" and after all of this, this is the way I perceive "Dynamic Range", I'm hoping someone can either correct or clarify this for me:

Dynamic Range = The difference, in decibels, between the quietest and the loudest sections of a musical performance or recording. The amount of decibels between the lowest volume and the highest volume in your audio.


So if the lowest volume on some audio is -10dB at any given time and the highest is 0dB, would I then have 10 decibels of dynamic range?


is there any term to describe the "average dynamic range" of some audio? would this be closely related to RMS ?


Thank you for your time and kind regards,
- ubik

[JamesMcp]

by the very nature of the word range indicates it covers all the values between the upper and lower limits of something (in this case, audio level). there would be not such thing as an 'average range'. your rms level can give an average (single) value at any point in time, but your dynamic range is exactly as youve described it.

[barefoot]

Dynamic Range is technically the ratio of the highest possible signal to the noise floor. So, for 24 bit digital the dynamic range is about 140dB theoretically and 115dB practically.

In audio engineering terms, I think what you're referring to is best termed Dynamic Headroom. This is the ratio of the highest possible signal to the nominal (RMS) signal level. So a "squashed" 24 bit recording still has a lot of dynamic range, but is mastered to have very little dynamic headroom.

Even so, a lot of people do use "dynamic range" more in the musical sense of the word; that is to say, the difference between the quietest passages in a piece of music and the loudest passages. So lets say you compress a track and adjust the makeup gain so it is sitting at the same nominal level as before. In this case you would still have the same amount of dynamic headroom, but the dynamic range in the musical sense of the word would be less.

Hope this helps!

Thomas

[ubik]

Hey thanks to both of you for your input.

Originally Posted by barefoot

Dynamic Range is technically the ratio of the highest possible signal to the noise floor. So, for 24 bit digital the dynamic range is about 140dB theoretically and 115dB practically.

In audio engineering terms, I think what you're referring to is best termed Dynamic Headroom. This is the ratio of the highest possible signal to the nominal (RMS) signal level. So a "squashed" 24 bit recording still has a lot of dynamic range, but is mastered to have very little dynamic headroom.

Even so, a lot of people do use "dynamic range" more in the musical sense of the word; that is to say, the difference between the quietest passages in a piece of music and the loudest passages. So lets say you compress a track and adjust the makeup gain so it is sitting at the same nominal level as before. In this case you would still have the same amount of dynamic headroom, but the dynamic range in the musical sense of the word would be less.

Hope this helps!

Thomas

Some great info in here , your help is much appreciated and I'll be sure to explain the difference between the technical definition and the musical sense of the term "Dynamic Range" to someone, if i ever need to, after this.


much respect to the gearslutz.

- ubik

[Cellotron]

Originally Posted by barefoot

Dynamic Range is technically the ratio of the highest possible signal to the noise floor. So, for 24 bit digital the dynamic range is about 140dB theoretically and 115dB practically.

In audio engineering terms, I think what you're referring to is best termed Dynamic Headroom. This is the ratio of the highest possible signal to the nominal (RMS) signal level.

Also termed by Bob Katz as "crest factor"

Best regards,
Steve Berson

[jdg]

more info about crest factor:
http://en.wikipedia.org/wiki/Crest_factor

[barefoot]

Originally Posted by Cellotron

Also termed by Bob Katz as "crest factor"

Crest factor is a bit different than dynamic headroom. It's the ratio of the peak waveform amplitude (not necessarily maximum possible waveform amplitude) to the RMS level.

This ratio is more akin to musical dynamic range. It just looks at the waveform properties and doesn't depend on the recording medium itself. Although musical dynamic range is something more like the maximum RMS level divided by the minimum RMS level.

But yeah, they're all good was of looking at it. Just depends on what property you're interested in.

[Bob Yordan]

Just put a couple of seconds with silence (min) before the song and you get nice dynamic ranges in all your songs, according to RMS readings.



When I do experiments with my plugs I can get RMS average levels at -7dB with RMS min at -60 to -80dB
in some cases, all depending on how dense the input is. What can bring down the average RMS is the
possibility to add low end bass.

[JohnRoberts]

Ok, lots of good info, but if I could expand on that.

Dynamic range of a medium or audio path would be the difference between clipping and noise floor, dynamic range of a recording would be the difference between the loudest and quietest section.

Crest factor is more of a short term measurement characterizing a waveform or sound by it's ratio between peak and average or RMS. A drum rim shot would have a high crest factor, while a compressed bass note would be quite low.

Dynamic headroom is an archaic (?) term related to audio power amp power supply capacity or ability to deliver brief loud transients (tone burst) above a continuous output level (AFAIK this is not used currently).

RMS (root mean square) is a subtly different way to characterize the average or total energy content of a waveform. Peak describes maximum excursion or deviation. Peak is useful to monitor as it tells you when you will run out of headroom or clip. RMS/average OTOH is more useful to represent apparent loudness in a mix or to balance L and R.

JR