First off, there is NO EXCUSE for analog audio as bad as any of the clips I just listened to.
Every receiver's design gets an "F" from me as regards a consumer receiver.
My Collins 390 sounds like this on 4 kc IF bandwidth. Which ain't bad if you can "slide" up. Or down.
This de-emphasizes the lower octaves, and restores some "clarity" of upper frequencies, which still aren't really there.
But, of course you can't with most consumer 10-khz step tune PLLs.
This is also a good point to remind or inform that the audio reproducable is exactly one half of the receiver's IF bandwidth.
That is, 10kc of IF bandwidth can give only 5kc audio, top end.
I believe that the Delco engineers fell into this classic engineering trap in the 1980's when they were told to design a radio that was 5khz wide.
The result is all the GM radios that only reproduce AM to 2.5 khz.
Either this was a bungle or intentionally done to make AM sound awful to those people unfortunate enough to purchase such newer radios.
Doesn't matter except for the possible conspiracy enthusiast, but unfortunately at this date we have a lot
of people who seem to think analog sounds this way.
Wrong! Analog is your ears! That's the standard! You CAN hear the difference!
Badly designed analog receivers sound this way and often worse, as they overload with poorly designed AVC circuits
containing "semiconductors'" with crap third order intecepts on intermodulation in the prescence of strong signals in the same amplifier stage.
Transistor-based circuits will never make as good an RF or IF amp as any tube based circuit.
Excuse this brief rant, while I pause for a wee sip of beer and catch my breath.
Now, on to the digital part of these samples. They are all grainy, "clippy" and unstable.
It almost sounds as though each speaker needs to clear their throat, but they never do.
Or like a slight voice-coil rub in the radio.
The voices seem disembodied, as if generated by software.
The audio voices appears to burst forth in sparkly "chunks" sounding nothing at all like a person across the table with whom I am conversing.
Regardless of frequency response, it is evident the engineers did not have enough bits at hand to deal with the logarithmic reality of loudness.
There are not enough "shades of grey" in the levels, especially evident at the lower levels of modulation, and it reminds me of an underbiased amplifier with its attendant zero-line crossover distortion.
I have not heard Sirius' codec, but this sounds just as bad as the codec on XM, where I can almost tolerate music if I like the music for whatever reason, but become deranged trying to listen to the talk channels, where the shp- tsk slp
ffft- spppft of every sibilant sound makes me wish I could hear fades, static crashes, and the 10 kc whistle instead, because they are LESS intrusive, and require no payments to coporations.
I would certainly hope the HD-FM sounds a great deal better than any of those!
(If the music wasnt cut off)