Silicon ChipAvoiding the penetrating bass beat - March 1991 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: Avoiding the penetrating bass beat
  4. Feature: Electric Vehicles; Pt.3 by Gerry Nolan
  5. Feature: Solar Electric Speed Record In Australia by Gerry Nolan
  6. Project: Remote Controller For Garage Doors, Pt.1 by Branko Justic
  7. Serviceman's Log: The case of the worn video heads by The TV Serviceman
  8. Project: Transistor Beta Tester Mk.2 by John Clarke
  9. Vintage Radio: Automatic gain control: what it is & how it works by John Hill
  10. Project: A Synthesised Stereo AM Tuner, Pt.2 by John Clarke & Greg Swain
  11. Back Issues
  12. Feature: Computer Bits by Jennifer Bonnitcha
  13. Project: Multi-Purpose I/O Board For IBM PCs by Graham Dicker
  14. Feature: Amateur Radio by Garry Cratt, VK2YBX
  15. Feature: Remote Control by Bob Young
  16. Feature: The Story Of Electrical Energy; Pt.9 by Bryan Maher
  17. Feature: Bose Lifestyle Music System Subscription Offer
  18. Order Form
  19. Market Centre
  20. Advertising Index
  21. Outer Back Cover

This is only a preview of the March 1991 issue of Silicon Chip.

You can view 43 of the 96 pages in the full issue, including the advertisments.

For full access, purchase the issue for $10.00 or subscribe for access to the latest issues.

Articles in this series:
  • Electric Vehicles: The State Of The Art (January 1991)
  • Electric Vehicles; Pt.2 (February 1991)
  • Electric Vehicles; Pt.3 (March 1991)
  • The World Solar Challenge (April 1991)
  • Motors For Electric Vehicles (May 1991)
  • Electric Vehicle Transmission Options (June 1991)
Articles in this series:
  • Remote Controller For Garage Doors, Pt.1 (March 1991)
  • Remote Controller For Garage Doors, Pt.2 (April 1991)
Articles in this series:
  • A Synthesised Stereo AM Tuner, Pt.1 (February 1991)
  • A Synthesised Stereo AM Tuner, Pt.2 (March 1991)
  • A Synthesised Stereo AM Tuner, Pt.3 (April 1991)
Articles in this series:
  • Computer Bits (July 1989)
  • Computer Bits (August 1989)
  • Computer Bits (September 1989)
  • Computer Bits (October 1989)
  • Computer Bits (November 1989)
  • Computer Bits (January 1990)
  • Computer Bits (April 1990)
  • Computer Bits (October 1990)
  • Computer Bits (November 1990)
  • Computer Bits (December 1990)
  • Computer Bits (January 1991)
  • Computer Bits (February 1991)
  • Computer Bits (March 1991)
  • Computer Bits (April 1991)
  • Computer Bits (May 1991)
  • Computer Bits (June 1991)
  • Computer Bits (July 1991)
  • Computer Bits (August 1991)
  • Computer Bits (September 1991)
  • Computer Bits (October 1991)
  • Computer Bits (November 1991)
  • Computer Bits (December 1991)
  • Computer Bits (January 1992)
  • Computer Bits (February 1992)
  • Computer Bits (March 1992)
  • Computer Bits (May 1992)
  • Computer Bits (June 1992)
  • Computer Bits (July 1992)
  • Computer Bits (September 1992)
  • Computer Bits (October 1992)
  • Computer Bits (November 1992)
  • Computer Bits (December 1992)
  • Computer Bits (February 1993)
  • Computer Bits (April 1993)
  • Computer Bits (May 1993)
  • Computer Bits (June 1993)
  • Computer Bits (October 1993)
  • Computer Bits (March 1994)
  • Computer Bits (May 1994)
  • Computer Bits (June 1994)
  • Computer Bits (July 1994)
  • Computer Bits (October 1994)
  • Computer Bits (November 1994)
  • Computer Bits (December 1994)
  • Computer Bits (January 1995)
  • Computer Bits (February 1995)
  • Computer Bits (March 1995)
  • Computer Bits (April 1995)
  • CMOS Memory Settings - What To Do When The Battery Goes Flat (May 1995)
  • Computer Bits (July 1995)
  • Computer Bits (September 1995)
  • Computer Bits: Connecting To The Internet With WIndows 95 (October 1995)
  • Computer Bits (December 1995)
  • Computer Bits (January 1996)
  • Computer Bits (February 1996)
  • Computer Bits (March 1996)
  • Computer Bits (May 1996)
  • Computer Bits (June 1996)
  • Computer Bits (July 1996)
  • Computer Bits (August 1996)
  • Computer Bits (January 1997)
  • Computer Bits (April 1997)
  • Windows 95: The Hardware That's Required (May 1997)
  • Turning Up Your Hard Disc Drive (June 1997)
  • Computer Bits (July 1997)
  • Computer Bits: The Ins & Outs Of Sound Cards (August 1997)
  • Computer Bits (September 1997)
  • Computer Bits (October 1997)
  • Computer Bits (November 1997)
  • Computer Bits (April 1998)
  • Computer Bits (June 1998)
  • Computer Bits (July 1998)
  • Computer Bits (November 1998)
  • Computer Bits (December 1998)
  • Control Your World Using Linux (July 2011)
Articles in this series:
  • Amateur Radio (November 1987)
  • Amateur Radio (December 1987)
  • Amateur Radio (February 1988)
  • Amateur Radio (March 1988)
  • Amateur Radio (April 1988)
  • Amateur Radio (May 1988)
  • Amateur Radio (June 1988)
  • Amateur Radio (July 1988)
  • Amateur Radio (August 1988)
  • Amateur Radio (September 1988)
  • Amateur Radio (October 1988)
  • Amateur Radio (November 1988)
  • Amateur Radio (December 1988)
  • Amateur Radio (January 1989)
  • Amateur Radio (April 1989)
  • Amateur Radio (May 1989)
  • Amateur Radio (June 1989)
  • Amateur Radio (July 1989)
  • Amateur Radio (August 1989)
  • Amateur Radio (September 1989)
  • Amateur Radio (October 1989)
  • Amateur Radio (November 1989)
  • Amateur Radio (December 1989)
  • Amateur Radio (February 1990)
  • Amateur Radio (March 1990)
  • Amateur Radio (April 1990)
  • Amateur Radio (May 1990)
  • Amateur Radio (June 1990)
  • Amateur Radio (July 1990)
  • The "Tube" vs. The Microchip (August 1990)
  • Amateur Radio (September 1990)
  • Amateur Radio (October 1990)
  • Amateur Radio (November 1990)
  • Amateur Radio (December 1990)
  • Amateur Radio (January 1991)
  • Amateur Radio (February 1991)
  • Amateur Radio (March 1991)
  • Amateur Radio (April 1991)
  • Amateur Radio (May 1991)
  • Amateur Radio (June 1991)
  • Amateur Radio (July 1991)
  • Amateur Radio (August 1991)
  • Amateur Radio (September 1991)
  • Amateur Radio (October 1991)
  • Amateur Radio (November 1991)
  • Amateur Radio (January 1992)
  • Amateur Radio (February 1992)
  • Amateur Radio (March 1992)
  • Amateur Radio (July 1992)
  • Amateur Radio (August 1992)
  • Amateur Radio (September 1992)
  • Amateur Radio (October 1992)
  • Amateur Radio (November 1992)
  • Amateur Radio (January 1993)
  • Amateur Radio (March 1993)
  • Amateur Radio (May 1993)
  • Amateur Radio (June 1993)
  • Amateur Radio (July 1993)
  • Amateur Radio (August 1993)
  • Amateur Radio (September 1993)
  • Amateur Radio (October 1993)
  • Amateur Radio (December 1993)
  • Amateur Radio (February 1994)
  • Amateur Radio (March 1994)
  • Amateur Radio (May 1994)
  • Amateur Radio (June 1994)
  • Amateur Radio (September 1994)
  • Amateur Radio (December 1994)
  • Amateur Radio (January 1995)
  • CB Radio Can Now Transmit Data (March 2001)
  • What's On Offer In "Walkie Talkies" (March 2001)
  • Stressless Wireless (October 2004)
  • “Degen” Synthesised HF Communications Receiver (January 2007)
  • WiNRADiO: Marrying A Radio Receiver To A PC (January 2007)
  • PICAXE-08M 433MHz Data Transceiver (October 2008)
  • Half-Duplex With HopeRF’s HM-TR UHF Transceivers (April 2009)
  • Dorji 433MHz Wireless Data Modules (January 2012)
Articles in this series:
  • Remote Control (February 1991)
  • Remote Control (March 1991)
Articles in this series:
  • The Technology Letters, Pt.2 (January 1989)
  • The Story Of Electrical Energy (July 1990)
  • The Story Of Electrical Energy; Pt.2 (August 1990)
  • The Story Of Electrical Energy; Pt.3 (September 1990)
  • The Story Of Electrical Energy; Pt.4 (October 1990)
  • The Story Of Electrical Energy; Pt.5 (November 1990)
  • The Story Of Electrical Energy; Pt.6 (December 1990)
  • The Story Of Electrical Energy; Pt.7 (January 1991)
  • The Story Of Electrical Energy; Pt.8 (February 1991)
  • The Story Of Electrical Energy; Pt.9 (March 1991)
  • The Story Of Electrical Energy; Pt.10 (May 1991)
  • The Story Of Electrical Energy; Pt.11 (July 1991)
  • The Story Of Electrical Energy; Pt.12 (August 1991)
  • The Story Of Electrical Energy; Pt.13 (September 1991)
  • The Story Of Electrical Energy; Pt.14 (October 1991)
  • The Story Of Electrical Energy; Pt.15 (November 1991)
  • The Story Of Electrical Energy; Pt.16 (December 1991)
  • The Story Of Electrical Energy; Pt.17 (January 1992)
  • The Story Of Electrical Energy; Pt.18 (March 1992)
  • The Story Of Electrical Energy; Pt.19 (August 1992)
  • The Story of Electrical Energy; Pt.20 (September 1992)
  • The Story Of Electrical Energy; Pt.21 (November 1992)
  • The Story Of Electrical Energy; Pt.22 (January 1993)
  • The Story of Electrical Energy (April 1993)
  • The Story Of Electrical Energy; Pt.24 (May 1993)
  • The Story Of Electrical Energy; Pt.24 (June 1993)
Publisher & Editor-in-Chief PUBLISHER'S LETTER Leo Simpson, B.Bus. Editor Greg Swain , B.Sc.(Hons.) Technical Staff John Clarke, B.E.( Elec.) Robert Flynn Darren Yates Reader Services Ann Jenkinson Advertising Manager Paul Buchtmann (02) 979 5644 Mobile: (018) 28 5532 Victorian Representative Hugh Anderson Pty Ltd (formerly McDonald Woodside & Associates Pty Ltd) , 119 Market St, South Melbourne, Vic 3205. Phone (03) 696 5411. Contact: Ian McDonald. Avoiding the penetrating bass beat Over th e last 20 years or so, hifi system s have becom e commonplace virtually every home now has one or more systems in different rooms. If you are a music lover, then you can only regard this development as good since it brings instant music within the reach of everyone. However, there are drawbacks to th is universality of hifi systems. The first is well known and is the tendency of some people to listen to their systems at ridiculously loud levels. This really has nothing to do with hifi and is fortunately becoming less common as peop le come to realise that music does not have to be loud to be enjoyable. The second drawback is less obvious and it is related to the ability of bass sounds to easily trave l though walls, floors and closed windows an d thereby disturb people who may be quite a distance away. This can h appen even though the sound level in the person's listening room is not particularly loud. So in spite of listening at quite modest sound levels , the bass from your hifi system could well be disturbing yo ur neighbours. How does this come about'? First , some popular music is recorded with very high levels of bass. Partly, this is to overcom e the limitations of cheap radios and sound systems and partly because young people tend to like lots of bass. Second, many peopl e play their music with the loudness control switched in and with bass boost as well. This leads to unnaturally high levels of bass , which is quite unpleasant to listen to for long periods . Third, people tend to compound the probl em of excessive bass by placing th eir speakers in the corners of the room - which makes th em sound even more boomy. Lastly, some hifi dealers sell spiked feet for loudspeakers so that instead of standing on the carpet, they sit firmly on the timber floor underneath. This is claimed to make the speakers sound better (hard to jus tify) but also has the effect of making the timber floor into a giant sounding board for the speakers. That can mean that the bass from your speakers can easily travel for hundreds of metres or more. How can yo u be sure that you are not offending in this regard? Easy, just set your system for your normal listening level at n ight and go outside and listen. Can you hear the music or the bass? If so, it is time for positive action. Consider that if you are disturbing someone tonight, they may decide to disturb you on some other night. Remember, your hifi system will give the best poss ible sound with no bass boost, no loudness switched in and with the speakers not placed in the corners of th e room. And forg et spiked feet for your speakers - th ey are another gimmick. Leo Simpson Regular Contributors Brendan Akhurst Jennifer Bonnitcha, B.A. Garry Crall, VK2YBX John Hill Jim Lawler, MTETIA Bryan Maher, M.E. , B.Sc. Jim Yalden, VK2YGY Bob Young Photography Glen Cameron Editorial Advisory Panel Philip Watson, MIREE, VK2ZPW Norman Marks Steve Payor, B.Sc., B.E. SILICON CH IP is published 12 times a year by Silicon Chip Publications Pty Ltd. All material copyright ©. No part of this publication may be reproduced without prior written consent of the publisher. Printing: Magazine Printers Pty Ltd , Rozelle, NSW 2039; Macquarie Print, Dubbo, NSW 2830. Distribution: Network Distribution Company. Subscription rates: $42 per year in Australia. For overseas rates, refer to the subscription page in this issue. Liability: Devices or circuits described in SI LICON CHIP may be covered by patents. SILICON CHIP disc;;laims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. Editorial & advertising offices: Unit 39, 5 Ponderosa Pde, Warriewood, NSW 21 02. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 979 5644. Fax (02) 979 6503. ISSN 1030-2662 MARCH 1991 3