First — and briefly, don’t worry ! — some personal historical background.
My journey in “computer audio” started many years ago with Logitech’s Squeezeboxes. From the very beginning, I looked for the best and more versatile file format. In those times, FLAC was not an option on Mac so I settled for AIFF, which was much better, musically, than ALAC, while preserving metadata, which WAV did not. When the time came to convert my library for use with “JRiver”, I was listening with a Bel Canto 3.7 and NuForce Ref 9 SE amps. I converted all the AIFF into FLAC and settled for the default compression level of “6”, as it was labelled “recommended”. My listening tests in these times didn’t indeed reveal any noticeable difference with AIFF and I rejoiced at the 50 % gain in file sizes. And forgot about it.
Fast forward to the autumn of 2021. After about two years with a Bartók (+ Rossini Clock), I could afford a Rossini. As I had the cash, I opted for the player over the DAC alone, considering the drive as a convenience. How surprised and puzzled I was, on the first listen, to discover that spinning CDs provided better results, more musical enjoyment than digital files — yes, even with Mosaic and MinimServer, I do play by the rules.
I couldn’t find any convincing, reasonable explanation… until I remembered this compression setting for the FLAC conversion and decided to do some tests. In short the results are… [Drum roll]… with compression level 0 (zero, the less compression), the sound is noticeably improved over compression level 6. I would say it’s probably equivalent to the CD and I’m very happy about it. My wife and I, we did some listening and comparisons with AIFF and WAV files ; we came to the conclusion that FLAC 0 was undistinguishable from AIFF and WAV and all these options are noticeably better than FLAC 6. I wouldn’t swear that it’s completely equivalent to the CD in all situations, as it would require very extensive testing with different recordings, different genres and so on, as you all know. What I can say, after days of listening to my converted music library, is that the music is more lively , more “life like”, got more of what we, audiophiles and music lovers, are looking for in our hobby. Anyway, I don’t feel the urge any more to reach for the CD — when I have it — as it was the case before conversion.
Let’s say I’m very happy with the improvement in sound quality that I could implement by converting the whole library. It’s also very satisfactory that it costs absolutely nothing moneywise ! To my ears, it’s a sonic improvement similar to upgrading cables, and you know how much this can cost !
So, in the end, I would advise anyone listening to local FLAC files to convert them into compression level 0. It costs nothing but the effort to do it — not much if you have the tools and the know-how — and either you have no gain or you have a very enjoyable gain musicwise. There’s nothing to lose, but a few megabytes of disk storage, depending on the size or your library — the difference in size between compression level 6 and level 0 is about 10 %. Seen the other way around : it’s not worth gaining 10 % disk space, nowadays, if it’s at the expense of the sound quality, especially if you’ve got gears in the dCS class !
PS : the other components of my set-up :
- Jeff Rowland 625 C2
- Duevel Bella Luna
- Isol-8 Substation Integra
- all wired with Cardas Clear but the power cords into Integra and into Jeff Rowland (Clear Beyond)