Where is my HD radio?

[O'Shag]

Depends on the tuner and the reception in your vicinity. We come back to the classic digital vs. analogue shootout. Problem is most people have never heard how excellent the sound is from a high quality analogue tuner receiving a clear signal. I don't have a great tuner right now, but when I receive 89.9 KCRW (out of Santa Monica College) and they broadcast bands as they play in the studio live the sound is amazing. Indeed its better and more true-to-life than any digitized signal can manage. Problem is, most listeners have to deal with multi-path interference which destroys sound-quality, and the HD signal sounds much more listenable. I have Sirius Satellite radio with my Dish Network which is essentially the same thing. Good quality sound, but not as good as high-quality analogue. I would love to see the broadcasters works on a system that maintains the analogue transmission, but improves it, and eliminates multi-path interference.

[Smokey]

Depends on the tuner and the reception in your vicinity. We come back to the classic digital vs. analogue shootout. Problem is most people have never heard how excellent the sound is from a high quality analogue tuner receiving a clear signal. I don't have a great tuner right now, but when I receive 89.9 KCRW (out of Santa Monica College) and they broadcast bands as they play in the studio live the sound is amazing.

I agree with you there. I have Hitachi analog Tuner (FT-440) which looks like a tank and sound much sweater than integrated receiver tuner.

But on the same note it might worth mentioning that no matter how much they improve FM, it is still inherently a Mid-Fi medium. And that is mostly due to its limited bandwidth (200khz) which can not be changed. That bandwidth only allow bandwidth allows for broadcasting a 15 kHz bandwidth audio signal.

Also, don't buy into any of the talk about "CD quality" audio with HDRadio. Aside from the lossy data compression, the audio signal beaming out to an FM transmitter almost always undergoes often heavy dynamic range compression. And most FM stations nowadays play their music off of digital servers, rather than CDs (again, doubtful that this playback is lossless). If HDRadio simply simulcasts the analog feed going to the FM transmitter, it won't be anywhere near CD quality.

Until Elapsed mentioned it in his post, I thought HD stand for High Definition radio and was expecting a much higher quality sound than FM (like moving from NTSC TV to HDTV). But all this talk about low bit rate, compressed sound and lossy format for HD radio make it sound like it is going to be DOA (Drumstick On Arrival ) even before it takes off.

May be I had my hopes too high

[O'Shag]

I agree with you there. I have Hitachi analog Tuner (FT-440) which looks like a tank and sound much sweater than integrated receiver tuner.

But on the same note it might worth mentioning that no matter how much they improve FM, it is still inherently a Mid-Fi medium. And that is mostly due to its limited bandwidth (200khz) which can not be changed. That bandwidth only allow bandwidth allows for broadcasting a 15 kHz bandwidth audio signal.



Until Elapsed mentioned it in his post, I thought HD stand for High Definition radio and was expecting a much higher quality sound than FM (like moving from NTSC TV to HDTV). But all this talk about low bit rate, compressed sound and lossy format for HD radio make it sound like it is going to be DOA (Drumstick On Arrival ) even before it takes off.

May be I had my hopes too high

Smokey,

thanks for the info regarding bandwidth. I didn't realize that. Clearly if there is such a limit in bandwidth (can that be changed?) then there is gong to be a limit to sound quality.

BlackRaven is of course correct, and for the most part and for most listeners, the interference problem does ruin it. I do enjoy listening to Sirius, but sometimes I hear the limit in soundquality. I must admit that HD Radio seems interesting, because its essentially the same given the digital broadcasting technology, and more importantly - ITS FREE!! The broadcasters win, because they get advertising dollars.

[pixelthis]

CHECK OUT C.CRANE company, if its a radio they have it, especially SANGEAN.
I used to connect my FM tuner to an TV antenna, the sound was quite good.
To say that FM is limited because it "only" goes to 15 khz or so is silly, most can't hear
too much past 13khz.
The problem with FM is programming, most of it is crap, spaced between commercials.
But proper FM, with a proper outdoor antenna, can sound quite good.

[O'Shag]

CHECK OUT C.CRANE company, if its a radio they have it, especially SANGEAN.
I used to connect my FM tuner to an TV antenna, the sound was quite good.
To say that FM is limited because it "only" goes to 15 khz or so is silly, most can't hear
too much past 13khz.
The problem with FM is programming, most of it is crap, spaced between commercials.
But proper FM, with a proper outdoor antenna, can sound quite good.

Very good point Pix. As I noted previously, I've heard some excellent sound quality from analogue broadcasts. I guess its very dependent on the quality of the material and of course on the lack of interference. We have an excellent Jazz station and some superb classical stations here in so Cal on FM radio. I think that an outdoor antenna is the only way to go to maximize signal quality.

[emaidel]

I know nothing about HD radio, other than what I've read in this thread. I had assumed the HD stood for "high definition," but just learned here that that's not so.

Like several other AR members, I've never considered FM a legitimate source for serious listening. It's not whether or not one is using a good outdoor antenna (or has one's tuner connected to cable), but the amount of signal processing an FM broadcast is subjected to. Almost all broadcasts are severely compressed, and often with what's known as "knife-edge" compression that's quite noticeable, and very annoying. dbx uses its patented "over-easy" compression, which is considerably less noticeable than that of the knife-edge variety, but it still a form of signal processing which, when used, degrades the original signal.

I can't speak from experience with live broadcasts, as I've never had the opportunity to listen to one here in South Carolina, or in the Denver area where I used to live. I can only hope that such broadcasts sound better than the stuff that's pumped out over the air most of the time. Still, whether live or not, tons of signal processing is used: the best FM can ever hope to be is as good as the source, which, other than a live broadcast is often a pretty ordinary CD player, or 16" turntable with an old Stanton 680EL cartridge. Most of the AR members who've posted on the site have considerably better equipment than that in their homes.

As it turns out my tuner (a Parsound T/DQ-1600) is a Stereophile Class-C recommendation. Big deal. I hardly ever listen to it, and nothing from it has ever sounded remotely close in fidelity to either my CD player or turntable. Now that I've replaced my older turntable with a Dual CS-5000, and equipped it with an Achromat platter mat, and replaced my CD player/converter with the Marantz SA-8001 SACD player, the disparity between them and my tuner is even more noticeable.

Just my two cents, again.

[pixelthis]

FM was once considered every bit as much a HI-FI medium as anything else.
BEFORE denon started with HT and quit with serious audio I bought their top of the
line receiver, 598 bucks, 75 wpc, 1985 or 86.
It had a quite serious tuner, with a special circuit for spurious channel rejection, etc.
INSTEAD OF A "TUNER ON A CHIP it had its own sheilded box, and was made of discrete components.
This was my last piece of serious gear before I got into HT, and all of the compromises it entails, anyway the sound was quite amazing .
And I am used to living 50 miles from serious stations (except the local pbs) and when I travel I am amazed by how good FM can sound when the station is close.
Now if they just put some programming on...

[Smokey]

To say that FM is limited because it "only" goes to 15 khz or so is silly, most can't hear too much past 13khz.

Don’t forget about harmonics

Music are complex electronic waves that more likely have higher harmonics that go beyond 15 kHz or even 20 kHz, and FM limited bandwidth tend to filter out higher harmonics. That is why for high quality medium such as SACD, the noise filter (signal bandwidth) is set at 44 kHz instead of 22 kHz which is for CDs.

Limited bandwidth (15 khz) also mean limited Dynamic Range and S/N ratio.

I havent really thought about if digital radio sounds compressed because my expectations of radio are much lower than CD sound quality. Digital radio does sound very good and I enjoy listening to FM radio to hear old classic rock and roll and to see whats new in music.

Are you using a HD tuner (Sangean??) hooked up to your system or a tabletop radio?

[Woochifer]

But on the same note it might worth mentioning that no matter how much they improve FM, it is still inherently a Mid-Fi medium. And that is mostly due to its limited bandwidth (200khz) which can not be changed. That bandwidth only allow bandwidth allows for broadcasting a 15 kHz bandwidth audio signal.

Not to mention the fact that broadcasters don't care much anymore about beaming out a quality signal. It's now all about maximizing volume, which means dynamic range compression and lots of it. For a lot of stations, the content doesn't even originate locally anymore -- the chatter and music get piped in from elsewhere, again with not a lot of concern for sound quality.

Until Elapsed mentioned it in his post, I thought HD stand for High Definition radio and was expecting a much higher quality sound than FM (like moving from NTSC TV to HDTV). But all this talk about low bit rate, compressed sound and lossy format for HD radio make it sound like it is going to be DOA (Drumstick On Arrival ) even before it takes off.

Like I said, the market for HD Radio and actually radio in general, is all about the mobile listeners. They are the present and future. HD Radio will sink or swim depending on its success at penetrating the car audio market, and the OEM installations in particular. Compared to the home audio market, the mobile market moves more quickly, and most people change cars a lot more frequently than they change audio systems. The uptake on HD Radio will occur very quickly once the format finds its way into OEM car audio systems. At that time, some demand for home units might pick up as well.

The home audio market for HD Radio is irrelevant in the big picture because people in general don't listen to as much radio at home as before. This is reflected in how audio equipment manufacturers treat tuners -- when was the last time you saw any receiver ad say anything about the AM/FM tuner, aside from mentioning that it's there? The quality of the FM tuner used to be a highly touted feature, but not anymore.

With so many other options now available for home listening, I doubt that HD Radio will spur a FM renaissance. HD Radio is all about increasing the resale value of radio stations by increasing the number of feeds that can fit into a given market's airwaves, and trying to give consumers reason not to defect over to satellite radio.

This is not really analogous to the digital TV transition, because HD Radio does not replace FM and there is no mandate in place for existing FM signals to switch off.