[BC] AM HD power levels

[Broadcast List USER]

While I have been a SERIOUS audiophile (Lynn Sondek LP-12 turntable,  
Keith Monks tone arms (plus Shure and others), Decca cartridges of  
different colors on those arms (if you don't get it, you don't get  
it), db systems pre-amp (and an attempt to use SWA phono pre-amps),  
home built amplifiers (with trials of Crown, SWTP, and others), Fried  
Model H speakers, Magna Pan speakers, Quad speakers, Koss  
electrostatic headphones.....), I have to tell you, Hi-Fi is for AT  
HOME LISTENING.

If you want your station, especially a classical station, to be an AT  
HOME ***ONLY*** station (for those seriously listening, sitting in  
the listening chair, doing nothing else except maybe drinking wine),  
maintain those huge dynamics/dynamic range -- make sure you don't  
touch the gain control until the peak light comes on, and don't turn  
it back up.

HOWEVER, if you want to make it listen-able in a car, or livable in a  
home where people are doing other things, like LIVING or cooking, or  
brushing their teeth, you must limit the dynamic range.

Yes, when I put a Telarc disk on, or others, or even some CDs, I  
EXPECT large dynamic range, and I expect the source to test my  
system, but when I am casually listening to the radio, I don't want it.

Radio NEEDS dynamic range limiting, or it makes people work too  
hard.  If you make them reach to the radio in the car too often, they  
are going to go away.

As a bit of an aside, there was once a COMMERCIAL station in the  
Washington, DC market where the CE had slow AGC and let the peaks  
exceed 200%.  Since his average modulation was between 60 and 80%, I  
didn't care one whit, even though I was involved in an extreme  
loudness war.  I thought what he was doing was very cool, sounded  
good, and was right.  even at 200%, he wasn't causing any  
interference to anyone.  Plus, while his dynamic range was limited to  
an extent, his station sounded good.  Later, he became a real audio  
killer.

We COULD "encode" processing information for the consumer, so they  
could undo the processing, or include processing in radios, but that  
isn't going to happen.

Still, if radio is going to be a consumer product, it NEEDS dynamic  
range reduction (as does TV).  It needs to be a no maintenance  
product for the consumer.

If you want to have a mass audience, you need to but Bob Orban (or a  
few others) in the driver's seat!


On Sep 1, 2008, at 2:02 PM, broadcast-request at radiolists.net wrote:

> Message: 5
> From: "Phil Alexander" <dynotherm at earthlink.net>
> 	<broadcast at radiolists.net>
>
> Bob,
>
> There was a time when the only audio "processor" was
> the hand of the control room operator on a pot. <g>
>
> In those days there were far less high energy, high
> frequency modulation instances. In fact, I suspect
> any peak hold audio spectrograph would have been
> classically triangular.
>
> I started in radio at an FM that had **NO** audio
> processing equipment except for a 100 W yellow bug lamp
> on top of the console that was slaved to the modulation
> monitor's overmod relay.
>
> Later, when I worked in master control at WBAA (long
> before the invention of NPR) the operator on duty was
> the only audio processor although we did have a peak
> limiter at the Tx for preventing negative overmodulation.
> The program was primarily serious/classical music in the
> evenings when I worked, and we were required to ride gain
> to maintain approximately 600 peaks per hour over 90%.
> All monitoring was done off air. The station did transmit
> 30 Hz to 15 kHz on AM. Switching from OTA to program
> monitor was audibly imperceptible to most although I could
> detect a slight difference. (When I was a kid, I could
> hear the difference because my ears had good response out
> to about 19.7 kHz and I could not stay in a room that had
> a TV with a noisy flyback transformer.) BTW, at WBAA,
> failure to monitor OTA and failure to average 600 peaks
> per hour were both cause for dismissal. This should give
> you an idea of the radio I was taught during my formative
> years.
>
> Many of the pre-1960 radios in serious high fidelity
> systems had excellent frequency response, and perhaps
> a noise limiter that could be switched in and out for
> AM. The practical effect was a system that corresponded
> with the FCC audio proof of performance requirements.
>
> I suppose it is fair to say that technically AM radio was
> not a system because the FCC did not **control** the
> receiver technical specification, but, practically speaking,
> anyone who wanted to receive the full audio spectrum of
> a station could buy a good tuner and plug it into their
> hi-fi. The point is that competent receivers were readily
> available. A couple of the names I recall were Sherwood and
> Fisher. As you mention, the H.H. Scott stuff was pretty
> good too.
>
> The early stereo exciters lacked the mono audio quality
> of earlier mono only exciters. As examples, the switch
> from Phasitron to direct FM in the Collins left something
> to be desired, and the addition of stereo with what was
> essentially an SCA generator in the Gates was a joke. My
> record for getting one of the tube type factory refurbished
> exciters to hold separation (IIRC either 27 or 29 dB) was
> 7 minutes after complete tune up on the bench in Quincy. Of
> course it did hold main channel frequency somewhat better
> than its successor, the infamous TE-1.
>
> ---------------------------------------------
> Phil Alexander, CSRE, AMD
> Broadcast Engineering Services and Technology
> (a Div. of Advanced Parts Corporation)
> Ph. (317) 335-2065   FAX (317) 335-9037