Audio Engineering Society Singapore Section

On Monday, 29 December 1997 at 7.00pm, members and guests of the AES Singapore Section gathered at the Ngee Ann Polytechnic - Clementi Road. Coffee and light snacks were served before proceeding to the conference room about 45 minutes later for a talk by Mr. Jibby Jacob, Manager of Studios and Outside Broadcast from the Radio Corporation of Singapore (RCS). 

Jacob, who is also Secretary to the AES Singapore Section, gave an interesting presentation on the search for a perfect audio recording media for radio broadcast to a packed audience of 5 members and 37 guests, comprised mainly of industrial audio engineers, researchers, academics and students from the local universities - despite the heavy downpour caused by the monsoon rain during this time of the year! 
 

Contrary to popular belief that the radio station uses only open reel tapes as the only medium for audio production and broadcast, there are currently about a dozen media in use. A survey of the various recordable audio media that has been used since the early days of radio broadcast was first introduced by Jacob along with a discussion of their strengths and weaknesses. One such early piece of equipment was the first successful US professional open reel tape (ORT) recorder introduced way back in 1948. Early multi-track recordings were commonly found on open reel tapes that had a tape length of up to 2400ft and could last merely an hour for a 2-track music recording! 

The earliest audio tape that was housed in cartridges (CART) was built in 1959. According to Jacob, the NAB cartridges were originally invented for car stereo and had durations that ranged from 7secs to 30mins. They were also found to be suitable for commercials in radio broadcast which have a short duration, between 30 to 45secs. 

Analog audio cassette tape was used mainly for vetting and proof of performance. It was never used for radio broadcast due to its limited dynamic range and poor sound quality. Nevertheless, it is still used for broadcast in some lesser developed countries, he added. 

The VHS tapes were used to download soundtracks of TV programmes such as the news and current affairs. It was also used to source sound tracks from movie trailers for creating radio's own trailers. 

From the analogue recording media, the focus of the presentation was switched to the digital recording media which can generally be classified into a tape-based format and a tapeless format. The tape-based formats include such things as the ALESIS' S-VHS, SONY's Hi-8 digital audio tape (R-DAT) and DASH open reel tape, and of course, the recently introduced PHILIPS' Digital Compact Cassette (DCC). The tapeless format includes magneto-optical (MO) disc, WORM compact disc (CD-R), SONY's MiniDisc (MD), Hard-disk drive (HDD) and also floppy disks. Among the other points highlighted, Jacob also pointed out to the audience that the tapeless recording format has faster access time to the recorded materials as opposed to the tape-based format, although the latter could offer higher storage capacity. Some of the applications of tapeless recording are CD mastering, audio for video post production, speech editing, archiving and sonic restoration, and multi-track music production. 

Some of the many advantages of embracing digital audio recording technology are its superb sound quality, flexibility in editing, alteration, time-scale modification, pitch shifting, for mono, stereo as well as multiple channel operations and also immediate access to the recorded materials. The agony of editing analogue tape recorded materials that actually involved physical cutting and splicing are fortunately gone! Other benefits include the ability to produce perfect copies and to perform multiple chain duplications with no deterioration in sound quality and enhanced operational features such as indexing, automation and searching. In addition, the cost of digital recording media is lower than the analogue media - by about one-third in terms of total cost for both hardware and software. 

Despite its many advantages, the major trade-off in digital technology is the high bit-rate requirements at CD sound quality standard. As a rule of thumb, 1 min worth of stereo digital audio signal at CD sound quality standard would take up approximately 10Mbytes of memory space! Some kinds of bit-rate reduction strategies have to be applied in order to reduce the high bit-rate associated with the digital audio format. Some of the algorithms that he mentioned were the MPEG and WAVE file formats. 

In the later part of the seminar Jacob explained the increasing popularity of the mini disc (MD), which is basically a consumer oriented format, in radio broadcast. Because it was originally targeted at the consumer market, the MD recorder is user-friendly. The technology is similar to that of a CD-R with the added advantage that it is re-writeable for countless times. 

Besides going in-depth into explaining the technicality of the MD system, Jacob also brought to the audience's attention his preference for the MD format over the older analogue open reel tape formats. The superiority of the MD includes ensuring digital audio quality recording with a full audio frequency response range of between 5Hz to 20Hz and a dynamic range of 105dB.
 

and unlimited perfect cloning! Random access of recorded data is also possible, unlike with tapes, which can only perform serial access. There is a write-protect feature in the MD to prevent accidental erasure of valuable recordings and editing is non-destructive; that is, what is done can still be undone! He quoted that the cost of the MD hardware is about S$3000 while the software is about S$7. On the other hand, the cost of the open reel tape hardware is higher at S$6000, while the software is about S$28. 

Finally, Jacob addressed the topic of digital versatile disc (DVD), which promises to be the "mother of all recording media" in the context of the radio industry. However, he said that there are still many issues yet to be resolved such as cost, copy protection, and date of availability, among others.

A very lively question-and-answer followed. One of the concerns raised by one of the members among the audience was the lossy compression associated with the MD format using ATRAC - a psychoacoustic bit-rate reduction algorithm - instead of using DAT. According to Jacob, DAT which is basically a tape format has several disadvantages which were discussed earlier such as difficulty in editing and slower access of data. Moreover, the difference in sound quality would not be perceptible between the MD and DAT for FM broadcasting. However, he stressed that for music archives, CD-R is normally used instead of the MD, even for voice-only materials.

Jacob, in his reply to another question, told the audience that RCS will not install any DVD recording system until the technology has matured sufficiently. The question-and-answer session went on well past 9.30pm - long after the monsoon rain had stopped!

Biography of Mr. Jibby Jacob

Jibby Jacob is currently the Manager (Projects) at MediaCorp Radio. With 16 years in the radio industry, his experience spans both music production & engineering. His current duties include the design and setup of both production & on-air facilities for the Company. Jacob has also consulted for Radio Nepal (RNE) & Laos National Radio (LNR) on behalf of Asia-Pacific Broadcasting Union (ABU). He has taught digital audio courses for both in-house trainees and for the Commonwealth Broadcasting Association (CBA). He is a member of the Institute of Broadcast Sound (IBS), UK.

Jacob who is a founding member of the AES Singapore Section has served in various positions in the Executive Committee, including Chairman (1998-2000). Currently, he is the Advisor to the Section. 

Copyright 1997 AES Singapore Section