Note: This is going to be a little complicated, so I will try to cover every factor in this problem I've had. I purchased some DSD (352 khz) files of solo piano music that's fairly dynamic and detailed, with loads of gorgeous harmonics. I prefer to play my music in 24/88 or 24/96 format, and also be able to convert to 16/44 WAV to play on my 256 gb Apple devices. So I purchased a well-respected converter (Mac version) to make the 24/88 FLAC and WAV files, and carefully followed the instructions given by the music critic who promoted the album, as well as the detailed instructions given by the converter gurus. Those 24/88 conversions not only wouldn't play on my PC in Foobar2000, they corrupted Foobar so badly that I had to reinstall it. That process of conversion from DSD to 24/88 and attempts to play on Foobar followed by reinstallation was repeated many times, with input from the persons noted above, with no success. Note that I have over a thousand high-res (24/88 to 24/192) WAV and FLAC files from HDTracks and several other such sites, and I've never had a single problem playing those on my Foobar2000 player. And I tested a number of those again during this process. So I finally decided to convert the DSDs to 16/44 WAV files, and those played just fine on Foobar2000. But when I converted those WAV files to FLAC, the FLAC files (Level 5 FLAC) were smaller than MP3s, i.e. about 23 percent of the 16/44 WAV size. Using that same Foobar2000 and both FLAC converters I have (ca. 2007 and 2014), I've converted several thousand CD/WAV rips to FLAC over the years, and none of those FLACs were less than 60 percent of the WAV file size. I even went a step further to see how my trusty FLAC converter could make files smaller than the corresponding MP3s - I converted a few MP3s (320 kbps, 4 minutes and 10 mb each) to 16/44 WAV tracks (44 mb each), and then I restarted Foobar and converted those WAVs to FLAC. Those FLACs, which originated from the MP3 files, were now 24 MB each, and Foobar showed a bitrate around 760 kbps when playing. The "23 percent" FLACs noted above showed a bitrate playing in Foobar of 290 kbps. So my question is, given that I cannot make a FLAC that's 23 percent of a WAV file size from any of the thousands of WAV files that I've ripped or purchased, or even from up-rez'd MP3s, what could possibly be in the WAV files I got from the well-regarded Mac converter that I purchased, that would trick my FLAC converter into making FLACs smaller than MP3s? The converter software gurus say that the DSD recordings have "extremely low complexity", which makes no sense, and doesn't fit with all of the other experience I've described.