Downloading Flacbox 5.3 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X is a product of everappz. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The software lies within Audio & Video Tools, more precisely Players.
From the developer:
Flacbox is a hi-res music player with an audio equalizer and bass booster. With this application, you can open almost any audio file on your Mac and listen to the music in a lossless format. You can move all your music to the personal NAS storage or cloud service to free up space on your computer. Then you can connect to the cloud service and listen to your music directly or download your favorite songs for offline playback.
You may want to check out more software for Mac, such as Forty-TwoDVD-VXPlus, yFlicks or JVC ProHD Clip Manager, which might be related to Flacbox.