20 April 2004

Digital Recording presentation

Notes for a presentation on digital recording techniques.

The Division has been using minidisc recorders for a number of years to supportthe teaching of Journalism and Media courses. The recorders are also useful for recording interviews and meetings, and provide a relatively high quality sound recording capability especially when used with good microphones.

The minidisc format is a proprietary format owned by Sony, and over the years Sony has changed the format a number of times: the newer formats always incompatible with the older recorders (although usually the newer recorders have supported the older formats to a greater or lesser degree).

The discs used in minidisc recorders are small recordable CDs that use a laser to encode the audio signal onto the disc: minidisc players read the discs and convert the sound to audible signals for replay. The sound to be recorded is compressed using the ATRAC encoder: a proprietary Sony system that is difficult to convert to digital formats without Sony or other licensed providers' equipment.

Why not use older analogue audio recording equipment? Anything with moving parts is prone to failure: the less moving parts the higher the reliability of a piece of equipment. Media like tape, cassette, film, magnetic or optical disks have a high failure rate, are difficult to administer, can vary in quality and may be expensive to purchase and process.

Digital recording offers the prospect of higher quality in smaller packages at a cheaper cost, and better control over the recorded material.

While minidiscs are digital, they are still mechanical devices that are prone to failure in the laser, the motor and the discs themselves. Repairs (involving replacing the laser and/or the motor) are costing us between $200 and $375 on a $450 purchase price.

The revolution in still photography over the last five years is a good example of the migration from analogue systems to digital: over the last few years digital still cameras have outsold film cameras and are increasing their lead. Some film manufacturers have announced that they are ceasing production of camera film, and some camera manufacturers no longer produce film camera or have announced production will cease in the near future.

Digital still cameras record onto media using no moving parts: solid-state memory storage devices that can be used to transfer files to computers over wires.

Currently domestic VHS video recorders are being overtaken by DVD recorders and Digital (or Personal) Video Recorders (DVR or PVRs). DVD recorders record video programs directly to recordable DVDs: PVRs to hard disk. Consumer and professional digital video recorders can now be purchased with no tape mechanism: instead the camera record to DVDs that can be played back to provide high-quality recording for watching or editing.

There are a number of digital portable audio recording devices on the market now.

In solid state the high end of the market is going for devices like the Nagra ARES BB, ARES-P / RCX220 or ARES-PII (see http://www.nagraaudio.com/pages/professionalaudio.php?etat=2).

There are many high-end professional audio for video solutions out there as well, (eg Fostex stuff or HBB Portadrive: see http://www.locationsound.ca/reco.html#renl Nagra also has a hard-drive version of the classic Nagra reel-to-reel: http://www.nagraaudio.com/pages/nagrav.php?etat=2). These devices are too complex, unwieldy and expensive for student use in theUniversity.

Professional minidisc is also popular with the market at the lower end, but the mechanical nature of the devices are of concern: the fewer moving parts the less likelihood of service requirements. Sony's proprietary format of the minidisc is a challenge for the University, illustrated very well by Sony's Hi-MD format not being backwards compatible with the existing players in the NewsBoss suite. Buying the new format will mean replacing all the portable and desktop units: assuming the same price points for Hi-MD desktops and prosumer portable recorders, it will cost the University about $25,000 to replace the existing devices with Hi-MD devices to give us the same level of resources that we have now.

Microcassette memo devices are giving way to MP3 recorders and other solid state or removeable media devices like the Creative portable audio devices, Olympus DM-20, Sony digital notetakers, iRiver MP3 player/recorder, and the iPod with Belkin Voice Recorder. Some of the Sony's use Memory Stick, and all of themuse a proprietary recording system of one sort or another.

Recently Journalism students at the University have become unhappy with the resources available to them, particularly minidiscs, to complete their assignments. Of the 25 recorders available last year, two were lost (last year), and five have broken this year, needing repair or in one case irreparably damaged. The Division had budgeted for additional and replacement portable minidisc recorders this year to bring the number available up to 30, but the models we purchase were discontinued pending the release of a new format called Hi-MD. This format is incompatible with the desktop players the students use to transfer their audio to the NewsBoss system (see the specifications for the new Hi-MD format).

Several existing high end portable minidisc models designed for journalists will be continued, around $700 to $1,000 RRP inc without an external microphone. These recorders are more complex than the existing ones in use, and the extra cost would reduce the number we could afford to purchase.

Old stock of some other models still in the distribution channel pending the release of the new Hi-MD recorders have been purchased and are being put into service as soon as they arrive: these recorders are different models and students will need to learn how to use them.

The Division is exploring alternatives to the minidisc recorder using non-proprietary formats that are also easier to use and provide for better transfers of interviews to the computer for editing. At this stage there are no obvious replacements, although this is a constantly changing field with quality improving and cost dropping month by month.

Students that provide their own recording devices can now incorporate their recordings into the NewsBoss system: over the April mid-semester break a new version of the NewsBoss software is being commissioned that will allow students greater flexibility in completing the tasks required of them for assessment: for anywhere on the Internet they should be able to transfer their stories, including audio, onto NewsBoss. This greater flexibility should reduce the demand on the available recorders.

There is a proposal to get Journalism students portable computers: with a good mic (and an iMic if there is no analogue input), they could use the portable with Sound Studio (Macintosh) or some freeware PC application to record and edit their sound on the computer. At the very least students should be informed (by their lecturers) about the possibilities for using portable voice recorders that don't require drivers to be installed on lab computers. All computers with USB ports available should be able to handle devices that use standardfile formats like mp3 or wav.

What we are looking for is in the price range of around $650 ex GST with provision for an external microphone, power supply, USB transfer and removable media (fully solid state types like compact flash, smart media, multimedia, secure digital, microdrive and memory stick that can be read by card readers connected directly to the computer. Standard AA or AAA rechargeable batteries are preferred.

The market is moving rapidly with no firm answers at the moment: Sony is reported [NY Times: free registration required] to be releasing a hard-disk-based system later this year, although it is unknown whether this reported device will support recording using an external microphone. Costs will come down and quality improve as the devices evolve, so committing now is a bit too soon, although we should be keeping ourselves informed and experimenting where we can.


These are the links from the presentation:

  1. Nagra
  2. Fostex and HHB Portadrive
  3. Sony ICDP28 (not the Memory Stick device)
  4. iRiver H140
  5. Olympus DM-20
  6. Creative Labs
  7. Belkin Voice Recorder
  8. NewsBoss (NewsBoss user name and password required)

Other resources

General article on digital field recordings: Tools for Digital Audio Recording in Qualitiative Research.

Minidisc guide from Transom.org (US public radio)


Consider using a portable computer with a good microphone and software like Sound Studio [Macintosh only, site licensed at the University of Canberra: contact the helpdesk for installation information], or Audacity, for Macintosh, Windows and Unix [free], add headphones and you have quite a good if a little bulky set up.