Hi-MD | The "Hi-MD" format can transform a standard "MiniDisc" into a versatile storage medium offering both high sound quality and high storage capacity.

What's "Hi-MD"?

"Hi-MD" is a next-generation format that has enabled the "MiniDisc" to evolve into a versatile storage medium for storing data of all kinds. While still using standard "MiniDiscs" for recording music, you can now almost double their capacity by applying the "Hi-MD" format. "Hi-MD" ensures superior audio quality by offering a choice of two different recording methods for music: linear PCM, which preserves every detail of the original sound source without compression; and "ATRAC", which can deliver high audio quality plus high compression.

Sony has also introduced the 1GB "Hi-MD" disc exclusively for "Hi-MD" use, which has the capacity to store as much as 34 hours* of recorded music. And, as a storage medium for PC data, it can also be used to hold images and text files.

*Approximate recording time when recording to a 1GB "Hi-MD" disc in Hi-LP ("ATRAC3plus" 64kbps) mode. Note that "Hi-MD" devices designed exclusively for playback have no recording function.

The "Hi-MD" format

New "Hi-MD" high density recording technology doubles the recording capacity of standard "MiniDiscs". So, in addition to using the new 1GB "Hi-MD" discs, you can apply the "Hi-MD" format to your "MiniDiscs" and enjoy much longer recording/playback times.

The "Hi-MD" format
Playback compatibility with "MD" format

With LinearPCM mode, record and playback in high quality sound without compressing the sound source.

LinearPCM mode achieves high quality sound recording without audio data compression. This function is useful for backing up your treasured music CDs. You may use optical cables to connect a "Hi-MD AUDIO " device and a CD player to retain sound quality*.

*Only CD players with optical capability can be used.

CD -          > CD player - Optical cable "Hi-MD AUDIO " recorder

Recording with a microphone

LinearPCM mode is compatible with digital, analog, and microphone recording; you can record and play back in high quality sound, without compressing the original sound source. This function can be used in various ways such as recording a music performance.

"ATRAC3plus" - the key to recording with higher compression while preserving high sound quality

"ATRAC3plus" is the next generation audio compression technology based on "ATRAC".
While "ATRAC3" was able to compress a CD to approximately 1/10 of the original size, "ATRAC3plus" is able to compress with higher quality at approximately 1/20 of the size.


34 hours* can be recorded on a 1GB "Hi-MD"

With a high capacity 1GB "Hi-MD" disc it is possible to record up to 34 hours of music data* when recording on a stand-alone "Hi-MD AUDIO" device. 1GB capacity even allows for easy storage of large capacity music data recorded in high sound quality LinearPCM and Hi-SP modes.

*Approximate recording time when recording to a 1GB "Hi-MD" disc in Hi-LP ("ATRAC3plus" 64kbps) mode.
45 hours can be recorded on a 1GB "Hi-MD" disc when transferring "ATRAC3plus" 48kbps audio data from a computer to a "Hi-MD AUDIO" device.

approx. 34 hours

Music formats and bitrates compatible with Hi-MD recording/playback

Audio Mode Recording Time
80 min. standard MiniDisc in "Hi-MD" mode 1 GB "Hi-MD" disc
Device (PCM) PC   
28 min. 1 hr. 34 min.
1 hr. 35 min. 5 hrs. 30 min.
Device (Hi-SP) PC   
2 hrs. 20 min. 7 hrs. 55 min.
3 hrs. 10 min. 11 hrs. 00 min.
Device (Hi-LP) PC   
10 hrs. 10 min. 34 hrs. 00 min.
13 hrs. 30 min. 45 hrs.
4 hrs. 50 min. 16 hrs. 30 min.
6 hrs. 10 min. 20 hrs. 40 min.
9 hrs. 50 min. 32 hrs. 40 min.
New format supported from spring 2005
5 hrs. 17 hrs.
Device For recording on a stand-alone "Hi-MD AUDIO" device.
PC For transferring audio data between a computer and a "Hi-MD AUDIO" device.

Note: The figures above are approximate recording times.
Note: PCM, Hi-SP and Hi-LP are recording modes available with "Hi-MD AUDIO" devices.
Note: Recording time calculations assume each track transferred from a PC is 4 minutes long.
MP3:  Common name given to MPEG-1 Audio Layer-3. Sampling rate: 44.1kHz (fixed bit rate).

Also suitable for storing computer data

"Hi-MD" is a removable, rewritable media with high capacity that is highly portable."Hi-MD" uses the FAT file system, making it possible to use "Hi-MD" formatted "MDs" and 1GB "Hi-MD" discs as versatile media for recording PC data files, such as images and text. Furthermore, as portable, rewritable PC media, "Hi-MD" complies with USB format's Mass Storage Class, ensuring that simply by connecting a "Hi-MD" product to a PC it is immediately recognized as an external storage device.