Android 4.4 supports a couple of new Bluetooth features, but one of them will undoubtedly appeal to the cries of OCD sufferers more than the rest: as part of an extension to Bluetooth AVRCP 1.3, Bluetooth audio devices can now directly control Android's system volume. If you use a lot of Bluetooth speakers or headphones, you know how maddening this kind of problem can be. Because your audio output device has its own volume setting independent of your phone or tablet, you're never quite sure how loud things are going to be, or if you'll need to adjust one or the other to get the sound where you want it.

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