I had a client who wanted a 6:20minute VO with music set to the parameters below with a maximum of 2MB. I've exhausted all my efforts on Audition, audacity, and online compressors and it won't go below 3.2MB.
The VO has to be shorter, right?
Normally you'd use the libsndfile settings for this, not wav. Have you tried that? You should get a much smaller file size.