This is a good start. What really makes SoX usable for me is the ability to "tune" the SRC. I'd like to see some more variable options like in the SoX Foobar plugin as shown in the attachment. If I want a really steep cut-off filter, I can do that, but I find being able to change the slope and the phase response fairly fluidly allows for much less intrusive filtering for different material. As you can see here, it's set for fully linear phase, 91% bandwidth, which starts rolling off the high end at 20KHz in this case. No joke, 91% bandwidth has about 1/10th the preringing of the default setting and that's more important to me than preserving bandwidth most people can't hear. I might even like to see the bandwidth option go down to 80% or so for when I need to convert something with very little high end (electric guitar etc.) It may be a good idea to add some more "under the hood" settings as well. SoX is extremely flexible and high quality, which is why I use it.