For my default audio player I wanted something similar that also did this stuff:
Here's the best programs I found:
I wouldn't use these programs as my main music player - but they're really great as the default audio program for quickly navigating through a bunch of audio files across your filesystem.
Try foobar2000 - It has the capability but I dont think it's on by default, highly customizable though, should be easy to enable by defaulyt.
nulloy is simpler, but i can't tell if its actively maintained.
Both are completely free.
EDIT oh yeah, clementine! Great piece of software, has waveforms if you want 'em
sure, something like this: https://www.dropbox.com/s/fkip5y2zjky98in/mockup.png?dl=0
taking the already available in audio player in quicklook, but extend it with waveform preview, scrub, and audio information (bitrate and depth, sampling frequency, ID3, artwork, peak/rms) and a looping functionality to preview small samples in loop.
when previewing lots of audio files it's cumbersome to have them opened in an app, since the functionality to play them back is already on Finder via QuickLook. But the waveform display is very useful (take a guitar part from a song, maybe it has only 2min of music in 5min file, where the rest is silence, and getting to see this when previewing is quite useful)
the waveform in this mockup is from an open source player ( http://nulloy.com/ ), which I believe could be forked/extended to support a quicktime plugin.