Dolby Digital Plus for Tablets tries to compensate for weak speakers
Dolby Digital Plus for Tablets tries to compensate for weak speakers
Can software optimizations make the speakers in today's tablets any better?
On most smartphones and tablets, speakers are an afterthought at best. While processor speed and core counts, graphical capability, amount of RAM, and even pixel density have all trended sharply upward since the original iPad rebooted the tablet market in 2010, speakers remain small, quiet, tinny, and prone to distortion—this poor performance is so expected at this point that speaker quality rarely merits more than a paragraph or two in reviews, when it's mentioned at all. The screens on devices like the 2012 iPad or the Nexus 7 look great, but if you want something that also sounds great, a good pair of headphones is likely your only recourse.
Ars took some time at last week's Consumer Electronics Week to speak with with Kevin Brennan, director of product marketing at Dolby Labs, to find out what Dolby is planning to do to make tablet audio better without waiting on hardware makers to get around to improving their speakers' quality.
Dolby Digital Plus for Tablets
Dolby has a bit of incentive to improve sound on tablets and phones: during a state-of-the-industry keynote earlier in the week, Chief Economist and Director of Research for the Consumer Electronics Association Shawn DuBravac noted that sales for 24" and smaller TV sets were down, and said that tablets and smartphones were mostly to blame. Mobile devices paired with streaming video services are replacing the small TVs (and attached media players, and discs) that used to find their ways into kitchens and bedrooms—all of these are items for which Dolby receives licensing fees.
Dolby Digital Plus for Tablets is Dolby’s bid to extend the existing Dolby Digital Plus specification (and its associated licensing fees) to mobile devices, enhancing playback while also trying to compensate for those devices’ innate shortcomings: namely, small, cheap speakers using low-powered amplifiers; and media played not just from retail DVDs, but also from YouTube, streaming sites like Hulu and Netflix, and video files downloaded and converted from any number of source formats.
"Our overarching goal is to create an immersive experience, so that you feel connected with the content," Brennan told Ars. "We strive always, irrespective of what the endpoint is, the screen size, to try and create a more immersive experience."
Dolby Digital Plus for Tablets focuses on manipulating audio to behave more consistently regardless of its format or the speaker setup of the tablet in question: to combat distortion, the Volume Maximizer function turns up the audio but levels off high peaks, while the Audio Regulator feature compensates for distortion caused by speakers playing sound louder than they were designed to; to prevent constant volume adjustments, the Volume Leveler lets you set a master volume for content and then adjusts all of your media to play back at that volume; the Dialog Enhancer brings dialog out from the ambient noise to make it easier to hear, and so on. Other features, like the Surround Virtualizer and Surround Decoder, attempt to give audio more depth and better emulate a surround sound experience while listening to headphones or a tablet with stereo speakers, while still others focus on making ambient noise and other subtleties more audible, creating the "immersion" that Brennan mentioned.
These enhancements look nice printed on a fact sheet, but without actual testing, it could all amount to so much marketing fluff. Brennan invited me to take a listen to some video clips played through a demo app, which could be used to enable and disable the Dolby filters.
Taking a listen
The tablet used to demonstrate all of these effects was a Samsung Galaxy Tab 10.1, a tablet that has been on the market for just over a year, and all of the media used in the demonstration were clips from older films and TV shows that, as far as I could tell, had been in no way doctored or altered for the sake of the demo—2004's The Incredibles, the late 2000s Showtime drama The Tudors, and 2009's Avatar. Brennan would first play the clips as they were without Dolby's optimizations applied, and then play them again with the filters enabled.
Indeed, the Dolby filters seem to be performing as advertised: dialog was louder, ambient noises were more audible, and the separation between the different audio channels was more pronounced, though for the latter it should be noted that the Galaxy Tab 10.1 does use stereo speakers mounted on either side of the tablet, while the iPad and many other tablets use a single speaker, often mounted on the bottom or rear of the device. For tablets with speakers beyond saving, the optimizations also made a noticeable difference while listening with a pair of cheap over-the-ear headphones: with Dolby’s filters, sound effects had an added depth that they otherwise lacked.
The end result in each case was sound that, while still subject to the shortcomings of tinny, bass-less tablet speakers, was indeed markedly improved from the same audio without Dolby's filters applied. However, there’s still a lot we don’t know, largely due to the controlled test environment: how do the filters work for devices like the iPad that use one speaker instead of two? How do they work for YouTube clips and other, less professionally produced content? The technology showed a lot of promise based on what I saw, but I’d still want to see it in the wild before declaring it a complete success.
Conclusions
Dolby Digital Plus isn't going to make the speakers in phones and tablets transcend their small size or cheapness—when working with such a small physical size and, in many cases, such low margins, there's a definite upper bound to sound quality that a software solution just can't overcome. What Dolby Digital Plus does do, however, is make the best of a bad situation: watching content on a device with the Dolby Digital Plus filters and optimizations enabled sounds demonstrably better than listening to the same content on the same device without the optimizations.
According to Brennan, Dolby is working with software and hardware makers to ship Dolby Digital Plus-enabled mobile devices later this year, though exact devices and dates are currently unavailable. Based on what I saw at CE Week, it looks like the technology can easily be enabled on older devices by means of software updates, at least if the experience on the year-old Galaxy Tab 10.1 was any indication. Whatever the technology's real-world merits, the massive list of current Dolby licensees suggests that Dolby has the connections it needs to push the specification through—look for it to begin appearing in shipping tablets sooner rather than later.
http://arstechnica.com/gadgets/2012/07/dolby-digital-plus-for-tablets-tries-to-compensate-for-sucky-speakers/