Pulling Good Analog Sound out of Severe HD "Self Noise"?

[Clark2]

Originally Posted by W9TR

...The easiest test to see if you have HD self noise is to switch your tuner to mono. If the noise goes away in mono, you have HD self noise or the signal you are receiving is not full quieting in stereo anyway. You need about 20 dB more signal strength to get full quieting in stereo vs mono. That's exclusive of HD self noise.

Tom -- Yes, I'm pretty sure I have HD self noise on one station, especially since another station of similar strength (at the tuner) without HD sounds quiet.

But you had seemed to imply (in your earlier post) that good post-detection filtering (or a better stereo decoder?) could compensate for a wide IF pass-band. That was the reason for my question about (2). Did I misunderstand, or can you get rid of the self-noise by post-detection filtering without increasing distortion by using a narrow IF?

The answer to this question would seem important for choosing a tuner to get great analog sound on a station with HD channels... -- Clark2

[W9TR]

Clark,
Narrow IF bandwidth and good post detection filtering both work to eliminate HD self noise.

Tuner implementations of wide and narrow IF’s and post detection filtering vary widely so it’s hard for me to make a generalization.

I think the only way to see if a tuner works for you is to try it out in your system. The proof is in the listening.

Tom

[cleeds]

Originally Posted by W9TR

... I think the only way to see if a tuner works for you is to try it out in your system. The proof is in the listening ...

+1. This is often true in audio, but especially so when evaluating a tuner. Reception conditions vary greatly and it's difficult to predict results with any accuracy.

[Formerly YB-2]

+2. Can do all reading of theory and analysis you want, but plugging in a proper tuner & antenna provides the correct answer.

[Clark2]

Originally Posted by Formerly YB-2

+2. Can do all reading of theory and analysis you want, but plugging in a proper tuner & antenna provides the correct answer.

I accept what you folks are telling me, but aren't you at all curious about how HD works and what specific artifacts it produces?

(Interestingly, the HD Radio group on Yahoo! appears to be dead -- the last post before mine is dated Feb. 20, 2014, and the moderator does not respond to email!)

I hear you telling me that HD does not sound as good as analog FM, but I don't hear any details about how it falls short. I know from my car-radio listening that it's much better than Sirius/XM. I presume that it's adequate in some situations (and it is certainly quiet). I suppose I'll have to find out for myself... -- Clark2

[Macuser]

^^^^I've had several very good tuners over the years and still have a couple of good vintage Mac tuners. My thoughts are no matter how good those tuners sound they cannot make up for the lack of programming, constant commercials or compression that is today's fm. Putting the same effort into a streaming set up will yield much better results and that's probably the reason Yahoo HD Radio group is no longer around

[cleeds]

Originally Posted by Clark2

I accept what you folks are telling me, but aren't you at all curious about how HD works and what specific artifacts it produces? -- Clark2

I've heard HD broadcasts more than a few times, and that's about all I need to know how well it works (not very) and what artifacts result (low fidelity).

Originally Posted by Clark2

(Interestingly, the HD Radio group on Yahoo! appears to be dead -- the last post before mine is dated Feb. 20, 2014, and the moderator does not respond to email!)

That doesn't surprise me - HD is essentially dead in the US.

Originally Posted by Clark2

I know from my car-radio listening that it's much better than Sirius/XM.

I'd say the net sound quality of HD and XM (via the satellites) is about the same. If you've found otherwise, it may be a result of the specific tuner you're listening to, and not the potential of the technology itself.

[rnrmf1971]

I've had 3 different HD tuners at my residence. The sound quality has widely varied between these 3 tuners but comparing to satellite radio, in my experience, isn't even close. The high frequency "swirling" sound that I've always heard in satellite radio isn't present on HD1 broadcasts, by and large. That sound on satellite radio literally makes me uncomfortable.

My issue with HD tuners has been how unforgiving they sound. The little Sony was very round sounding but had a higher noise floor than the HD tuner implemented in the Marantz AV8802A processor that I currently use and enjoy, and would think is as good as HD radio can sound.

There was a Sony on Audiogon, yesterday, btw.

[W9TR]

Clark, you asked about some of the specific artifacts HD radio produces and how it falls short.

From my listening with a Sony XDR-F1HD forced to analog only (no blend) vs HD1:

1. HD1 was unable to accurately reproduce massed strings on MPR 99.5 KSJN classical concerts.

2. On MPR A Prairie Home Companion I was unable to tell the difference between a new Martin guitar and a 50 y.o. Martin guitar both played by the company’s president. Both guitars sounded the same. On the analog main carrier the difference was clearly audible and I had a preference for the sound of the older guitar.

3. On HD1 I was unable to hear the hall sound on familiar classical recordings where it was clearly audible on the analog main carrier.

I sold the Sony XDR-F1HD and never looked back. HD radio is not a Hi-Fi medium.

HD radio is also the Camel’s nose under the tent in that Ibiquity has proposed an all-digital future with no analog main carrier - effectively obsoleting all of our analog tuners and removing the only hi-fi radio alternative we have.

Tom

[Clark2]

Originally Posted by rnrmf1971

I've had 3 different HD tuners at my residence. The sound quality has widely varied between these 3 tuners but comparing to satellite radio, in my experience, isn't even close. The high frequency "swirling" sound that I've always heard in satellite radio isn't present on HD1 broadcasts, by and large. That sound on satellite radio literally makes me uncomfortable.

My issue with HD tuners has been how unforgiving they sound. The little Sony was very round sounding but had a higher noise floor than the HD tuner implemented in the Marantz AV8802A processor that I currently use and enjoy, and would think is as good as HD radio can sound..

Thanks, rnrmf1971 -- That's quite helpful. I have yet to hear good (that is, single-channel) HD in a quiet background on a good system. Sirius/XM, on the other hand, exhibits serious artifacts even in the car. I notice particularly on solo violins, and sometimes on solo piano, a high-frequency noise band that appears over the higher notes but that doesn't vary in frequency with the pitch of the notes -- some kind of peculiar processing artifact that, as you say, is quite unpleasant. I would not expect HD to sound that bad, based on the better codec they appear to be using, but the proof is in the listening... -- Clark2