Speed test for me shows 11.25 Mb/s. Some sites actually give me a download around 1.3 MB/s, but most are a much lower rate. As wa2ibm suggested, the choke might be at the site from which you're downloading (most likely), or somewhere along the route (less likely), rather than your connection or in Sonic.net's network (least likely).
What happens if you download multiple files (from different sites)? Is the sum of the download rates higher than what you saw on that specific file?
Have you tried Sonic.net's FTP test