snoopy@doghouse.gwd.tek.com (Snoopy) (10/29/87)
[ followups have been set to rec.audio only ] Okay, gang, you think you've heard everything, right? WRONG! Check out the October issue of _Hi-Fi Answers_ (a magazine from the UK). The article "Gifts Of Unknown Things" is absolute *must* reading! Some brief quotes: "Linn noticed how a telephone and battery-operated alarm watch caused a similar deterioration in sound quality to an extra loudspeaker, and once again the sympathetic vibrations theory was used to explain it. The flaw here is that battery watches without an alarm mess up the sound just as much as those with." "Further tests showed that a battery on its own -- especially if wired with a resistor across its terminals to make it pass current -- caused deterioration in sound quality." Obviously they should have used a metal film resistor and wired it with 4 gauge finely stranded oxygen free wire. :-) "Next he found that sound quality improved when various objects within the room -- a brick fireplace, a door -- were wiped with the treated foam." Gee, I wonder if I could use my zerostat to treat my fireplace, or if I need the official foam? "But the biggest surprise came when Peter tried treating the battery with a resistor across its terminals -- to his amazement he found that this item actually improved the sound in the room after it had been wiped." "The answer turned out to be simple: leaked energy from the AC mains supply. This was having the effect of ionising the air which in turn created a complex network of charge potentials across the surface of conductive objects. The presence of stray electromagnetic fields interacting with this leaked AC field seemed greatly to increase the ionising effects, thereby worsening the sound." Obviously, Peter Belt is either a genius or a lunatic. I suppose the first question is: by what mechanism could ions affect the sound? Snoopy tektronix!doghouse.gwd!snoopy snoopy@doghouse.gwd.tek.com
wolfgang@mgm.mit.edu (Wolfgang Rupprecht) (10/30/87)
In article <9312@tekecs.TEK.COM> snoopy@doghouse.gwd.tek.com (Snoopy) writes: > [ a quote from Peter Belt from _Hi-Fi_Answers_ ] > "The answer turned out to be simple: leaked energy from the AC mains supply. > This was having the effect of ionising the air which in turn created a > complex network of charge potentials across the surface of conductive > objects. The presence of stray electromagnetic fields interacting with > this leaked AC field seemed greatly to increase the ionising effects, > thereby worsening the sound." Well, Peter does sound like he has a great career ahead of him. Is he into radio communications with the dead also? ;-) Seriously, I have told of reports about exposure to various electrically induced fields. The claim is that large ion flows, and large ac magnetic fields as by power-lines, both effect you slightly, but in entirely different ways. The claim is that large ion flows (ie. from a terminal that has a cheap *very* non-conductive screen), will "bathe" you in this flux. This has the effect of sticking charge on facial hairs, insulating skin flakes etc. No ill effects come from this charge directly (the human body is *quite* conductive, once you get past the insulation of the skin's outer surface). The effects come from: 1) the negatively charged particles (ie. including half of the smoke, dust and dirt in the world) that is constantly flowing away from the screen, being repelled by the ions which are also moving away, and 2) the positively charged particles (the other half of the smoke, dust and dirt) that also get stuck to your skin, after being attracted by the negative charge just stuck there, and trapped in the surface oils, etc. Luckily the two effects tend to cancel out each other. So is that why comp-u-nerds have most of the world's supply of acne? ;-) I have seen quite a range of surface charges on various CRT screens. The old VT-100, that I had once, worked better than most electostatic air cleaners. I never needed a glare-guard for that. It attracted its own (self healing) matte-surface. Other terminals don't even make the finer hairs on the back of your hand stand up when you hold your hand near the screen. (Actually, a conductive spray, as used to protect CMOS work environments, would probably work wonders for cheap crt screens.) On ac magnetic fields: I heard a bit on NPR a few months back about a high tension power line study. It claimed higher levels of stress on subjects exposed to 60hz magnetic fields for long durations. They went on to say that strong e-fields (such as found near high voltage lines) had no noticable effects. I'm not sure how one can verify "stress levels". What does ring true about it is that the human body does have quite a low impedence internally. Any exterior e-field would be attenuated (inside the body) by the ratio of the air's resistance to the body's, a very large number to be sure. This same low impedence makes it easier to induce small currents by alternating magnetic fields. Now, how does this effect Peter Belt's stereo? Well, if Peter lived near both a high tension power line, and a cheap terminal manufacturer ... ;-) Wolfgang Rupprecht UUCP: mirror!mit-mgm!wolfgang ARPA: wolfgang@mgm.mit.edu (IP addr 18.82.0.114)