To the anti-IBOC crowd

[Chuck]

I have never noticed on my factory Bose radio in my '99 Infiniti G20 (which has excellent AM DX reception BTW). I will try in when I travel to other markets. It may be the issue where some stations are broadcasting more sideband interference than those in my market.

My wife had an Infiniti with a Bose radio, and it worked very well. I was impressed. Just try tuning one channel up and one channel down from any AM IBOC station. I will be very surprised if you don't hear a loud hissing sound that resembles white noise. I can sure hear it on Dallas stations. I'm not the only one who hears it, and it’s not just on one radio either.

On FM, the sidebands are harder to detect. An open channel with no signal usually shows up as white noise unless the radio has a muting circuit, in which case it is dead silent. The IBOC sideband noise is slightly different sounding than inter-station white noise, but most people probably would not detect the difference without doing a side by side comparison. Most likely, they’d just assume that it is the same inter-station noise they have always heard. Somewhere a couple of hundred posts ago, I enumerated the differences and pointed out how to differentiate between the two sounds. Several people seemed to agree that it was an accurate description of the noise. I don't have time to go back and search for that, but it might be worth revisiting.

As I type this, I wonder if the Infiniti radio has muting on AM? That would be quite unusual, but if it does, it might explain why you don't hear it. It's funny; about half the people who post here say they hear the sideband hash. The other half says they don't hear it at all. Taking out the 5 or 10% of people who have some kind of serious ax to grind, most of the rest of us are merely interested observers who like radio. Some are even involved in the business. I doubt that very many of them are crazy or deaf. In fact, I'm familiar enough with people on both sides of this discussion and other than their views on this subject, they seem normal enough. There must be something more to this than meets the eye.

Either that or maybe we are ALL crazy. We do waste a lot if time here…..

 

[louisNatl]

I will try it in my Infiniti. It receives several distant AM stations that broadcast in IBOC during the early morning and evening hours. I receive WABC like a local station here in Atlanta during those hours and I'll try to see if I notice hiss. You may be right that the radio is muting it which is why I can't detect it.

 

[w9wi]

On FM, the sidebands are harder to detect. An open channel with no signal usually shows up as white noise unless the radio has a muting circuit, in which case it is dead silent. The IBOC sideband noise is slightly different sounding than inter-station white noise, but most people probably would not detect the difference without doing a side by side comparison. Most likely, they’d just assume that it is the same inter-station noise they have always heard.

In my car (2002 Ford Focus) on the first-adjacent channels to a strong analog-only station, I hear modulation splash. On the first-adjacents to a strong IBOC station, I hear white noise. The difference is fairly apparent - but I can see where a non-techie might not notice.

 

[SUPERCASTER]

All primary or secondary coverage area HD AM or FM stations have adjacent channel HD digital modulation noise on every radio I have tried (several dozen) including HD radios. Perhaps some radios that might mute the noise, or listeners who mistake the adjacent channel HD signals for normal inter-station noise might be causing the confusion.

 

[rwagoner]

It seems that many of you argue against HD because of the noise on the sidebands, especially on AM. What do you think will save the AM band?

Here is a FACT, not an opinion:

HD radio sidebands are a real annoyance when I travel. My seek button on the car radio locks on the sidebands - AM or FM, they are loud and raucous, and I have to push seek again to actually hear the station. And then if it isn't a format I want, I have to push seek again TWICE, once to get the loud raucous upper sideband, then again to find the next station (which if it is IBOC I get yet another loud annoying sideband).

None of my radios with seek functions do that. None of the five, all different brands. Home and car.

 

[w9wi]

My seek button on the car radio locks on the sidebands - AM or FM, they are loud and raucous, and I have to push seek again to actually hear the station.

None of my radios with seek functions do that. None of the five, all different brands. Home and car.

I've seen this happen, on my car radio. (2002 Ford Focus) It doesn't happen every time nor on every station, but it does occasionally happen.

I don't imagine any listeners will know it has anything to do with HD Radio. They'll probably just assume their radio is broken.

 

[rwagoner]

My seek button on the car radio locks on the sidebands - AM or FM, they are loud and raucous, and I have to push seek again to actually hear the station.

None of my radios with seek functions do that. None of the five, all different brands. Home and car.

I've seen this happen, on my car radio. (2002 Ford Focus) It doesn't happen every time nor on every station, but it does occasionally happen.

I don't imagine any listeners will know it has anything to do with HD Radio. They'll probably just assume their radio is broken.

Years ago when I had one of the first aftermarket digital AM/FM/8-Track car stereos, it would do that. Back when stations were only analog. Go figure.

It was not aligned correctly, most likely.