When deciding what format(s) will be the most suitable to store and play your digital audio collection, the main things to consider are:

• Compression
• Encode/Decode Speed
• Compatibility (i.e. which software and hardware can support this format)

Below are 2 scenarios, each with our recommended encoder(s) and settings:

SCENARIO 1. Time and Compatibility ARE an issue, but Disk Space IS NOT

• PC (Internal HDD): Lossless, FLAC -5
• Backup: 1:1 backup of the above on archive medium (DVD, External HDD etc.)
• Portable (DAP): MP3, LAME 3.98 -V 2 or -V 3

FLAC is the most hardware compatible lossless encoder, and though it's not the most efficient encoder when it comes to compression rates, it's extremely fast at both encoding and decoding.

LAME MP3 at -V 2 is transparent for most people most of the time in ideal listening environments, so if anything this format and setting is going to be more than adequate for your portable (DAP).

SCENARIO 2. Disk Space IS an issue, but Time and Compatibility ARE NOT

• PC (Internal HDD): Lossless TAK -p4m (solo piano music) and LossyTAK --standard (-q 5), -q 6, or --extreme (-q 7.5) for everything else.
• Backup: 1:1 backup of the above on archive medium (DVD, External HDD etc.)
• Portable (DAP): MP3, LAME 3.98 -V 2 down to -V 5

LossyWAV is a variable bit-depth pre-processor for lossless encoders, which takes advantage of the "wasted bits feature" of current lossless encoders such as FLAC, TAK and WavPack, leading to significantly higher rates of compression whilst maintaining transparency.

Although LossyWAV is technically lossy, it's more like a lossless format since it's transcode-safe (you can use it as a transcode source for transform codecs such as MP3, AAC, OGG etc.) and it's future-proof (i.e. once processed with LossyWAV transcoding to other lossless formats is a lossless process, so you can move from TAK to FLAC without any quality loss).

LossyWAV makes significant reductions on almost all music except piano music, for this reason we recommend treating solo piano music as a special case and encoding it losslessly with TAK -p4m.

LOSSLESS COMPRESSION CAN VARY GREATLY DEPENDING ON THE MUSIC

We used a sample of 9 tracks, each 60 seconds in length, to simulate a varied music collection, plus one reference track of white noise. The 9 tracks in the sample set are:

1. Classical - Quiet Piano [Mozart's Piano Sonata No.4 in E flat major - I. Adagio by Uchida]
2. Classical - Busy Piano [Bach's English Suite No.2 in A minor I. Prelude by Gould]
3. Classical - Symphonic, Loud [Mahler's 2nd Symphony - I. Allegro maestoso by Haitink]
4. Jazz - Quartet, Soft [Coltrane Quartet - Say It (Over And Over Again)]
5. Jazz - Orchestral, Loud [Charlie Mingus - Hobo Ho]
6. 60's Pop - Moderate (Original CD Release) [The Doors - Break On Through]
7. 60's Pop - Loud (Remastered CD Release) [The Doors - Break On Through]
8. Modern Pop - Loud [Songs: Ohia - I've Been Riding With The Ghost]
9. Modern Pop - Very Loud [The Flaming Lips - Race For The Prize]

Should you wish to run your own tests, you can download these samples in FLAC format here: GPA Encoding Sample Set.zip (53MB).

The tracks were encoded with:

• FLAC 1.2.1 (-5)
• TAK 1.1.1 (-p4m)
• LossyWAV 1.0.1.0 (--standard) > TAK 1.1.1 (-p2m -fsl512)
• MP3 LAME 3.98 (-V 2)

Here's how the various encoders fared (click on the graph and table below to enlarge):

Here's the actual bitrates:

SO, HOW MUCH SPACE AM I GOING TO NEED?

A 1000 CD Collection @ 60 mins per CD, uncompressed will require 591 GBs of HDD space (44100Hz x 16bits x 2 channels x 3600 seconds x 1000 CD's). Based on the compression rates of our small sample this is how much space would be required to store a 1000 CD audio collection:

• WAV = 591 GBs [Uncompressed]
• FLAC -5 = 348 GBs [59%]
• TAK -p4m = 332 GBs [56%]
• LossyTAK --standard = 189 GBs [32%]
• MP3, LAME 3.98 -V 2 = 84 GBs [14%]
• MP3, LAME 3.98 -V 5 = 61 GBs [10%]

Now multiply that by 2 to include your backup.

---

See the Software Encoders section for recommended software.

When files have been encoded, they are ready for tagging.