Meeting Topic: Compression for Timbre and Artifacts of File Compression
Moderator Name: Steven Liddle
Speaker Name: Former AES Past President, Jim Anderson and Prof. Alex Case, AES member
Meeting Location: Royal Technical University (KTH), Kista
Once again Jim Anderson and Alex Case graced us with their presence after visiting the student section in Piteå.
Jim kicked things off with an examination of the effects of lossy compression techniques such as MP3. We were lucky enough to have borrowed a pair of ATC SCM50 monitors from a local distributor so we had a chance to hear the sometimes subtle effects of the compression artifacts. Using a process of sum and differencing we were able to hear the isolated artifacts and listen back to the recordings again and understand the changes to the overall sound.
Alex continued his theme of using compression artistically in the studio. This time he demonstrated the use of compression for altering the timbre of sounds. Using artificially contrived visualisations of amplitude envelopes we were better able to appreciate the results of using various attack and release settings. Alex played several examples of recordings he had personally worked on which clearly demonstrated the subtle and dramatic effects that can be achieved with compressors. One particular sound that stood out was a clavinet that was transformed to a sound much more reminiscent of an electric guitar.
Written By: Steven Liddle