The first impression you get of Sound inDepth is not very positive. This sound editor not only forces you to install Pando (a P2P file sharing tool) if you want to enjoy all of its functionalities with no restrictions, but also displays a dark-colored interface that doesn't flatter the program. But no matter how biased you are, your view may change radically after using it.
Leaving those flaws aside, Sound inDepth is actually a good sound editor that includes a wide range of effects and filters to apply to your music files. The program's window shows the wave graphic of the opened file (tip: use the zoom tool to work in a much more comfortable way) and applying filters is as easy as selecting a certain area and then click on the desired filter in the program's menu.
Sound inDepth supports the most common formats and also enables to convert files from one to another. The program includes some other interesting extra tools such as an ID3 tag editor and a recording tool that can save sound from any source on your system.