Re: re: Power usage
"Prime suspect has to be the processing needed to extract a clean mux bitstream from the analogue domain, with all its distortions, reflected signals, strength fluctuations as surroundings change or the radio moves. That's never going to be cheap."
...except that DAB can utilise multipath broadcast signals and combine them in order to produce enough signal to be able to reproduce the signal without issues. See the section on Single Frequency Networks
"It appears it's not particularly effective either. Exposed right there is why FM is a more appropriate technology for inherently difficult reception conditions, it doesn't need heroic efforts to receive and doesn't break catastrophically when those efforts fail. And doesn't eat batteries trying to do it."
FM fails in a number of ways - there is only a limited range of allocated frequencies for FM radio - 88-108 MHz. Within that, there have to be enough transmitters for the national broadcasters, plus enough for all the local area broadcasters - and frankly there isn't enough space....and bear in mind that in some area's you might have multiple transmissions for the same radio station.....if they were on the SAME frequency, you'd have no clear reception due to interference. Also, at the edge of reception, background noise on FM transmissions can be if-putting and likewise, listening to say some light classical music on Radio 3 can be less than ideal, if the background noise is too great.
Using Band 3, you can have many more stations all broadcasting at once. (There are 37 ensembles allocated in UK - with somewhere between 4 (at "best quality") and maybe 10 (at low quality) stations per ensemble - so lets say maybe a total choice of over 300 stations). DAB broadcasts don't suffer from random noise, and they have potentially a wider bandwidth, *IF* the broadcasters used say a 256k or 320k signal (with 320k being almost synonymous with CD quality). The issue with sound quality is simply down to transmission costs - if it was cheaper then DAB broadcast rates could be increased and sound would be better.
(However, there is also the possibility that if CD quality music was broadcast over the air, would a lot of people simply record said broadcasts, instead of buying the music ??)