FLAC is better than MP3 simply because it is lossless. Some peoples state that they don't hear any difference between FLAC and high bitrate MP3 files. It's true for most people who don't use professional music equipment. With any pair of decent headphones you can easily tell the difference between a 128kbps and FLAC. Between 320kbps MP3's and FLAC's, the difference is more subtle, but still very much existent, especially when it comes to a good number of instruments playing at the same time, and a 320kbps MP3 encode suddenly sounds "crowded". This difference is incredibly noticeable with metal songs that rely heavily on cymbals for example, where they are always washed away by other instruments in crappy encodes.
Just a few facts:
- MP3 always work with 16bit audio (CD quality), it not suitable for 24bit DVD audio
- The sampling frequency of MP3 is limited to 48000 Hz, however it is enough for lossy compression
- MP3 doesn't support multichannel audio, only Mono/Stereo supported
MP3 is a proprietary codec and required license fee (the last MP3 patent expired on December 30, 2017)
- FLAC takes up more space on the hard drive. In most cases, FLAC is 5 times larger than an MP3 file
Well, you can't make unequivocal conclusions about which format is better, because they are designed for different purposes. FLAC is great for storing high-resolution music at the cost of larger file sizes. MP3 is economical in memory consumption and is not much inferior in sound quality in a street environment.
My recommendations, listen to FLAC at the house and listen to mp3 on portables. Audio Converter Plus will help you to convert FLAC album to MP3. If you have decent audio equipment in your home, you can tell the difference between FLAC and 320bit MP3 or at least I can with my ears. MP3 seems to destroy the high end range of frequencies and makes instruments like cymbals sound washed out.