Well there's a day for everything. World book day on 7th March. That's a big thing. And 22nd March 2013 is of course Dynamic Range Day. It's also; organise your home office day; as young as you feel day; education and sharing day; international day of the seal; world day for water.So Dynamic Range Day is not quite as big as World Book Day, but still of some cultural significance.
Dynamic Range Day is all to do with the "loudness wars" in the music industry. Basically over time music recordings have become louder and louder. Listen to an album from the 80's and one now, and the default volume is higher. That can be really noticeable playing music live at discos using some of those original classic recordings with newer recordings. This issues become sufficiently well recognised that some of the DJ software now tries to control that difference out.
That all sounds simple enough, and you would think it can be controlled by the user at playback. However there's something a bit more complex happening which cannot be undone at playback. In short by inflating the volume at recording time, the quiet bits end up being made louder, and proportionally more so than the naturally loud bits That reduces the variation in the sound, loosing some of the crispness and making it a bit more muffed, and basically less interesting.
There's some great video explanation on youtube at the dynamic range day web site... illustrated with Michael Jackson's Thriller.
Here's the essence of it.
1. The original recording. Note the quiet intro and then the spikes which indicate the louder drum beats.
The central band will be accentuated to increase the loudness.
2. Increase the loundess.
The overall loudness is increased. The difference between the low and high volumes is now less.
3. The overall effect.When played again at the same volume as 1 above, then it's those spikes - red here - which are now missing from the recording.
Research also seems to indicate that listening becomes more fatiguing, basically harder to listen to. So the Dynamic Range Day is a campaign to encourage those recording music to build in a minimum variation or range into the music, technically at least 8 decibels. Here here. Or should that be hear hear.
Sources and thanks: dyanmicrangeday.co.uk; wikipedia:loundness war
