MacDSP 0.3 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The application lies within Audio & Video Tools, more precisely General. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
MacDSP is a digital signal processing program for the Mac; it filters audio in real-time.