Introduction to Dolby Volume
A few weeks back, Dolby invited us down to London to have a gander at one of the latest additions to the Dolby portfolio: Dolby Volume. Now for a sound company, this may seem like an uninteresting or unimportant title, after all, volume is what volume does - louder or quieter, right?
But having previously worked alongside the guys at TrustedReviews
and having overheard tales from the Editor, who previously experienced early development of this technology, as saying it was the best thing since the invention of the speaker, we obviously had to hear for ourselves.
Instead of something cliché like "it makes your sound more cinematic" or gives "a more enveloping surround experience" (or +1 for any other combination of PR speak), Dolby Volume satisfies a few feature requests needed for a long time, although you may have only occasionally realised.
The first part satisfies a problem of having multiple devices sending multiple volume levels to your TV or home theatre. In a world where a Sky/Cable Box, Games console(s), Digital TV, Blu-ray, DVD, Hi-Fi audio playback (CD for example), and/or an HTPC are all common features of a modern living room, all of which pipe through a different volume to your speakers. You turn up your movie to get the full effect of the bass and that "cinema feel", but then later you decide to have an hour on the 360 only to find Microsoft deafens you with its load screen, as it bellows so loud the neighbours start hammering on the wall.
Not only that, but what about but what about the volume level difference between the TV programmes you want to watch and the obnoxiously louder adverts you inevitably ignore. Everyone can relate to diving for the remote to mute some annoyingly happy jingle informing you how remortgaging your house can allow you to get into even more debt, at 20dB higher than was needed.
For those in the UK who use the (fantastic) BBC iPlayer service online this is also a problem. You hit play and the five second introductory BBC animation starts, only to be followed by the actual program that bears absolutely NO volume correlation to any other program you've just been watching! See for yourself, try skipping from Heroes
to Top Gear
or Live at the Apollo
. (Actually Buzzcocks
was worst for this but the series finished so I can't use that example any more).
Now imagine a device that sorts all that out in one, uniform volume - simple, but a really great idea, right? So, that's basically Dolby Volume in a crude nut shell. A normalising/gain control feature that works on the fly to make sure that you can hear both the tender, loving whispers in that late night movie, without waking the family as someone chucks a pipebomb through the window, breaking the moment (of your movie.. not your living room) with a bang. Only, in typical Dolby fashion, it's more complicated than all that.
Dolby explained that it's not just about flat-lining everything, instead it keeps the dynamic range of the audio by modulating the EQ to enhance the bass and fine detail, rather than just leaving you listening to the mid-tones only.
In Dolby-speak it is described as: "A sophisticated combination of spectral and time-based loudness analysis enables Dolby Volume to quickly and properly correct level differences without creating compression artefacts or undesirable pumping in the audio signal.