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AM HD TURNOFF PACE ACCELERATES
- Thread starter Savage
- Start date
Fair enough. So if the return on the IBOC investment is zero, why on earth should any AM station spend money & resources on installing it? Seems like throwing money down a hole, if you ask me.
BTW, it is possible to have very decent sounding analog audio with IBOC turned on. WBBM has proven that for a few years now. Cheap radios will still pick up a little noise from the sidebands when tuned to the desired frequency, though.
WBBM actually has done as good a job as possible in adding enough upper end peaking to provide
sufficient intelligibility on consonants.
There still is an objectionable amount of hiss on any radios I use or encounter when listening to WBBM,
and tuning TO WBBM, you are always pre-greeted by the insane whooshing roar on the adjacent 2 channels.
This is noise is maybe more offensive than the the hiss when trying to listen.
I know there are radios so dull sounding it's hidden, but these are either highly selective by design as "communication"
receivers, where a very low signal to noise ratio is expected, or radios designed to make AM sound muddy intentionally.
It's like adding snow to a video signal. then deliberately reducing the contrast level so that the snow is less
obvious.
I can listen to WBBM, just not for very long.
At work, in the shop, there are any 2 flexible hoses for air-tools that leak and hiss, so the noise is somewhat covered up.
So there I can listen a little longer without annoyance.
sufficient intelligibility on consonants.
There still is an objectionable amount of hiss on any radios I use or encounter when listening to WBBM,
and tuning TO WBBM, you are always pre-greeted by the insane whooshing roar on the adjacent 2 channels.
This is noise is maybe more offensive than the the hiss when trying to listen.
I know there are radios so dull sounding it's hidden, but these are either highly selective by design as "communication"
receivers, where a very low signal to noise ratio is expected, or radios designed to make AM sound muddy intentionally.
It's like adding snow to a video signal. then deliberately reducing the contrast level so that the snow is less
obvious.
I can listen to WBBM, just not for very long.
At work, in the shop, there are any 2 flexible hoses for air-tools that leak and hiss, so the noise is somewhat covered up.
So there I can listen a little longer without annoyance.
I was very excited when IBOC came on the scene. WLW did a good job at processing their audio and it was neat listening to them on my car radio at 150 miles out with full quieting. However, throw in a thunderstorm, and their range is limited to less than 10 miles. The thunderstorms in the Midwest are severe with frequent lightning, and by the time the digital signal recovers, another lightning discharge destroys the digital signal again. The digital signal may not recover for an hour or so under these conditions. Unless the system is improved and is impervious to electrical noise, the AM system is toast. IBOC may work well on KFI because of the lack of thunderstorms in the area. Perhaps a listener from LA could give us a report.
BTW, WLW has had their IBOC off for about 2 weeks. It is still on WCKY (1530) but may be off on WSAI (1360), but I am too far away to make a positive determination on WSAI.
BTW, WLW has had their IBOC off for about 2 weeks. It is still on WCKY (1530) but may be off on WSAI (1360), but I am too far away to make a positive determination on WSAI.
WWJ 950 in Detroit has *finally* made a similar upgrade within the past couple days after giving its listeners crummy audio for the past several years (other than for 6 weeks last fall when IBOC was turned off; U-M football may have had something to do with that).
On my home theater audio receiver, I can enjoy AM 950 with no IBOC hiss bleedover at all! In fact, that has long been the case. Having 10 kHz-like analog audio greet me today was like Christmas in July for me. That being said, on my clock radio, the hiss remains impossible for me to eliminate, even when carefully tuned to the main frequency. (WJR, CKLW, WUFL, and even WDTW sound glorious on that same radio.)
Whoever did the engineering work on WBBM and WWJ should fix WSCR and WBZ, too, assuming that hasn't already happened.
My OEM car radio is one of those receivers designed to make "AM radio sound muddy intentionally." Overall, though, the sound quality on it is not terrible. I've heard plenty worse. The worst offender is a Hyundai Sonata I rented a year ago to go on a business trip. The AM bandwidth on that thing reminded me of a walkie-talkie; I'm not exaggerating! It was pathetic.
AM IBOC offers a choice between 5 kHz or 8 kHz analog audio bandwidth. 5 kHz mode only requires one of the two IBOC digital sidebands to be decoded in order to receive the digital audio, while 8 kHz mode requires both sidebands to be decoded, thus reducing digital coverage area in exchange for its benefit in analog audio quality.
In NYC, WFAN, WCBS, and WINS use 8 kHz mode, while WOR, WADO (when they have the IBOC on), and WQEW use 5 kHz mode.
In NYC, WFAN, WCBS, and WINS use 8 kHz mode, while WOR, WADO (when they have the IBOC on), and WQEW use 5 kHz mode.
Geographer said:
In the past, David Eduardo has commented on the AM HD stations in the LA area and noted they tend to work very well on his car's stock HD radio. I guess it helps that the ground conductivity there isn't pitiful and many of the stations running HD are 50 kW during the day.
And I'll second the crappy report on the Hyundai Sonata AM radio — I rented one a few years ago and it was so pitiful sounding as to be comical. It's almost like they went out of their way to make it sound really, really bad. There wasn't any reception improvement for the tradeoff, either. It sounded bad and wasn't a particularly sensitive headunit. I've got access to a Mazda with a "worse than telephone" AM section, but the tradeoff is it's incredibly sensitive and fairly selective as well. I've had no problems receiving WINK for Fort Meyers on it, and I'm halfway across the Gulf in coastal Alabama, 14 miles inland.
A lot of factory car radios these days sound terrible on FM as well, because they roll off the high end so much that you have to turn the treble all the way up just to get good sound -- and then of course when you switch over to a CD or the aux input, you have to turn the treble back down or else the tweeters will sizzle your ears out!
And also, most factory car radios require a very strong city-grade FM signal to hear anything in stereo -- anything less gets fully blended to mono. Some radios have even gone so far as to omit the "ST" indicator, probably because they figure you're be hearing mono most of the time anyway.
On AM, a brickwall cutoff at 4.5 kHz is the usual practice, because the radio is built for the worldwide market, and in continental Europe with 9 kHz channel spacing, 4.5 kHz audio bandwidth is used to eliminate adjacent-channel interference. This is considered acceptable for talk programming, but of course sounds like crap with music.
And also, most factory car radios require a very strong city-grade FM signal to hear anything in stereo -- anything less gets fully blended to mono. Some radios have even gone so far as to omit the "ST" indicator, probably because they figure you're be hearing mono most of the time anyway.
On AM, a brickwall cutoff at 4.5 kHz is the usual practice, because the radio is built for the worldwide market, and in continental Europe with 9 kHz channel spacing, 4.5 kHz audio bandwidth is used to eliminate adjacent-channel interference. This is considered acceptable for talk programming, but of course sounds like crap with music.
satech said:
I've got a good stock system in my car with 6 CD changer, FM-AM and Satellite 230 watts overall 2 subwoofers etc. Every band sounds good including FM except of course on AM it sounds like there is a pillow over the speakers. It's sensitive and selective even voice is even muffled, I can't even stand to listen to talk shows on it.
The IBOC is off again on 1560 WQEW. They had it off for about a month earlier this year, but this time it may be more permanent because they've also increased their audio to the full 10 kHz NRSC bandwidth (last time, they just left it at 5 kHz). However, their hourly ID still says "WQEW and WQEW-HD1 New York" (which is incorrect because AM HD stations are supposed to be just "-HD", not "-HD1").
It's also still off at 1280 WADO, another station known to turn off their HD for a month or two at a time and them flip it back on for another few months. (If it's so inconsistent that listeners can't depend on it, I wonder why they bother to keep using it at all?)
It's also still off at 1280 WADO, another station known to turn off their HD for a month or two at a time and them flip it back on for another few months. (If it's so inconsistent that listeners can't depend on it, I wonder why they bother to keep using it at all?)
Zach said:
The only two HD stations worth listening to in LA are KFI and KNX. Both have high power signals, and neither is directional.
Ground conductivity in LA ranges from good along the seacoast to wretched (inland in the high desert and Coachella Valley). But both those stations have usable analog signals over the entire LA radio market, and somewhat beyond.
Geographer said:
The LA area does not have a lot of lightening, but deserts (and LA is technically "semi-arid desert") have a certain high residual noise level. And LA has horrendous man made noise; it takes about 15 mV/m to get ratings results.
KFI battled dueling CODECS for the first year or so (cell phone calls sounding like Darth Vader, etc.) and finally got it. KFI is close, but occasionally reports from outside the station are mashed by the artifacts.
KFI's HD is good in a stock car radio to about 100 miles out from the transmitter in the daytime... waaay beyond the LA market itself. KNX does well in all parts of the LA metro except the Antilope Valley, but their analog signal there is not terrific either.
Kudos to Savage for starting a topic with 94 pages, and grow-wing.
I'm not sure if this has been mentioned before, but a 50Million mW station formerly known as WQYK-AM (etc.), is not running iBoc since the switch to calls of WHFS to reflect the new Sports station on 98.7. As I have always had problems receiving the station in Sa-ra-so-ta!, (it is virtually a non-existent station) I'm not sure how long it's been turned off.
Jeff in Sa-ra-so-ta!
I'm not sure if this has been mentioned before, but a 50Million mW station formerly known as WQYK-AM (etc.), is not running iBoc since the switch to calls of WHFS to reflect the new Sports station on 98.7. As I have always had problems receiving the station in Sa-ra-so-ta!, (it is virtually a non-existent station) I'm not sure how long it's been turned off.
Jeff in Sa-ra-so-ta!
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