[BC] Re: It s Eureka over IBOC down under

[Robert Meuser]

Robert Orban wrote:

>
> The FM pre-emphasis curve was more-or-less complementary to the HF 
> power handling of vinyl records using RIAA equalization. So everything 
> was pretty good back in the days of vinyl. However, the availability 
> of CD (which has flat power-handling vs frequency) eventually moved 
> the record industry to brighter mixes that pre-emphasized FM could not 
> accommodate without either reducing average modulation dramatically or 
> applying very audible HF limiting. Some would argue that today's CD 
> are mastered way too bright, but the fact remains that pre-emphasized 
> FM analog is incapable of handling this material in an audibly 
> transparent way without reducing average modulation by something in 
> the order of 10 dB compared to today's standard practices.
>
> Bob Orban


While obviously you are correct, the operative word is transparent.  CDs 
need a lot of work before they can be properly (not tranparently) 
broadcast.  Some vinyl had the same problem. If the audio is made to 
conform to the 'correct' power distribution and in the case of CDs they 
are unclipped, FM transmission is improved. Digital receivers cure all 
but the pre-emaphasis issue.   On the other hand, some CDs are so 
severely processed, that they will chew up MPEG codecs badly enough that 
you are swapping one problem for another.

R

R