Decibel is an odd little program. On one hand, it’s frightfully barebones, and probably not fit for the same sort of demographic as, say, Banshee. Its scope is strictly an audio player, and as such, it offers no tag or metadata editing whatsoever: the developer claims that standalone programs do it better, and strictly speaking he is correct: EasyTag or Mutagen offer much better capabilities, but I personally don’t think it’s such a stretch to expect basic tag editing abilities in an audio player. Mutagen, for example, is used in a slew of audio players even simpler than Decibel.
Oddly enough, Decibel out of the box comes with no support for libraries at all: it has only the ability to browse directories. I had to manually enable libraries, and then set them up (Decibel allows you to have multiple named libraries, which is a rare feature). Switching between either file views or directory views occurs with a drop-down box; I would like for multiple libraries to be accessible through the tree view at once, but such is not the case at this point in time.
As for library browsing, Decibel takes a rarely-used path, eschewing the paned concept in favor of a tree-view, sorted/split by alphabet; this is the same behavior you’ll see in Exaile, which itself copied it from Amarok. I personally find re-sortable tree views to be more useful than paned browsers, but that’s a personal conceit and not indicative of general usage.
Decibel’s preferences screen is mostly an overview of available modules, which themselves have configuration screens: it has desktop notifications, last.fm integration, album art, the aforementioned library views, and others. Beyond that, there’s not much to customize about Decibel.
Like most other players, it doesn’t know how to handle my album without an artist (only composer/performer), listing it as an Unknown Artist—which is then rather strangely filed under the letter “U” as though it was name instead of an error. Album art was touch and go: I didn’t actually get any to show up, though Decibel has a function to download it en masse.
In Summary:: Decibel Audio Player is still relatively early in development (despite having recently reached 1.00), but I don’t foresee it becoming a big player in the market; its spartan approach may garner it praise from users who want very little, but I find a lot of its performance and conventions (and its vision) to be too rudimentary to gain much traction in an environment where GTK audio players are a dime-a-dozen.