A Radio Shack success story!

[Tom Wells]

Strong storms including one tornado swept across Chicago monday afternoon, so I stopped by the local Radio Shack to
audition the Accurian during periods of QRN.
In Skokie, Illinois, this free-standing store was originally a "Miami Subs" franchise.
The HD radio was on a shelf, near the Sirius equipment, and it WAS powered up.
All the flourescent lights were on, all the TVs were on, etc.
The FM antenna was in its original wadded state. The AM loop was askew but vertical.
It was decodong an FM-HD, which kept dropping out, but immediately (5 sec) "reconnected".
This is about 9 miles from downtown Chicago transmitters.
Most of the FM-HDs worked the same. I did not unwad the FM, but proceeded immediately to the AM test,
where I noticed this store noise environment was only 1/3 as bad as might be expected.
I found that all 50 kw AMs could be picked up in HD, but the loop had be rotated 90 degrees for WLS AM vs the others.
WLS was 40 miles south, the others 25 miles west.
While any of them did decode in HD, they all dropped and reconnected 2-3 times per minute.
None of the lower powered AM HDs did decode, though they were audible in analog.

The sound in FM is acceptable either way, but only if kept to a low level.
If I turn it up to "full attention to the radio" the FM has a pronounced zinginess I would rather not hear in audio.

The sound on the AM is unacceptable either way.
The analog has less crispness than old-fashioned PlainOldTeleService, and none of the audio presets ever could unmuddy it.
Then when the HD kicks in, there is a distracting "chorus" effect happening, where it sounds much like a simple digital chorus box.
It actually sounds like each person is twins, speaking in almost perfect unison.
Why one person needs to sound like two, I can't understand.
It could also be described as sounding like a standing wave.
There is also the strange rendering of clicks and other extraneous room noises, which sound glitchy.
There is also the garbling of the human voice as bad as any selective sideband fading ever was in the ole shortwave days.
This "el-weirdo audio" is not worth the soiling of the analog signal.

My position is unchanged, but it's a resounding success for this particular Radio Shack.
The manager, it turns out, had tried other places where the radio did not work, so that's why the display was where it was.
You guys can't say it doesn't work if it was working with the antenna wadded up.

 

[Mike Walker]

Thanks Tom. I know we've tangled, but that's exceedingly fair, and appreciated.

I would point out that the speakers in the radio are, as Don Imus used to say frequently, "just awful". Used as a component tuner, the Accurian is surprisingly good. On strong analog fm stereo (WKBC FM...100kw here in Wilkes County NC), it's quiet, clean, fully separated, and rock solid. On more distant fm stations, the (excessive) blend and HF rolloff take their toll on analog signals, undoubtedly adding to the impression that HD is much brighter and cleaner. It IS, but the comparison is admittedly exaggerated by the reception of analog which is clearly compromised. Of course without the blend and hf rolloff, it would still be compromised, by hiss and multipath distortion. It's a tradeoff, but the design brief for this product obviously included "do whatever is necessary so the listener never hears ANY noise". Well noise is often preferable to muffled mono. Still, it's (the Accurian) a great value, and Tom obviously found it to work as solidly as many of us have claimed.

 

[radiopilot]

Thanks Tom. I know we've tangled, but that's exceedingly fair, and appreciated.

I would point out that the speakers in the radio are, as Don Imus used to say frequently, "just awful". Used as a component tuner, the Accurian is surprisingly good. On strong analog fm stereo (WKBC FM...100kw here in Wilkes County NC), it's quiet, clean, fully separated, and rock solid. On more distant fm stations, the (excessive) blend and HF rolloff take their toll on analog signals, undoubtedly adding to the impression that HD is much brighter and cleaner. It IS, but the comparison is admittedly exaggerated by the reception of analog which is clearly compromised. Of course without the blend and hf rolloff, it would still be compromised, by hiss and multipath distortion. It's a tradeoff, but the design brief for this product obviously included "do whatever is necessary so the listener never hears ANY noise". Well noise is often preferable to muffled mono. Still, it's (the Accurian) a great value, and Tom obviously found it to work as solidly as many of us have claimed.

So you would agree Mike that the HD signal is:

Quote:

"The sound on the AM is unacceptable either way.
The analog has less crispness than old-fashioned PlainOldTeleService, and none of the audio presets ever could unmuddy it.
Then when the HD kicks in, there is a distracting "chorus" effect happening, where it sounds much like a simple digital chorus box.
It actually sounds like each person is twins, speaking in almost perfect unison.
Why one person needs to sound like two, I can't understand.
It could also be described as sounding like a standing wave.
There is also the strange rendering of clicks and other extraneous room noises, which sound glitchy.
There is also the garbling of the human voice as bad as any selective sideband fading ever was in the ole shortwave days.
This "el-weirdo audio" is not worth the soiling of the analog signal."

As Tom has said, the Am audio on HD sounds like crap and you accept this as your comment suggests:

Quote:
"Tom obviously found it to work as solidly as many of us have claimed."

Well that answers it all, your hearing must be askew and now accept what everyone has been trying to say about HD and it's noise...

Quote:
"The sound in FM is acceptable either way, but only if kept to a low level.
If I turn it up to "full attention to the radio" the FM has a pronounced zinginess I would rather not hear in audio."

So basically there's no audible difference that FM sounds better than analog in his listening test.

The speakers on these HD radios will remain becase the main function of these units is a clock or table radio and that's it's purpose.. it's not a component unit and not used for such purposes, if you have to use all sorts of cables to hook up this unit to a component audio system what purpose is that on your nightstand or kitchen table, not to mention the antenna cabling to get the HD radio to pick up the HD signal!

Useless products hastily engineered to meet the Ibiquity date for FCC implementation of IBOC!

Radiopilot

 

[Mike Walker]

Ibiquity didn't create the damn codec. THAT is what defines sound quality. Time smearing is an unfortunate artifact when low bitrate coding is done poorly. I have no experience with AM HD. But that codec would sound identical on FM HD, or on an internet stream at 32, or 20kbps. "Time smearing" is one of the reasons to keep bitrates reasonable, and pre-processing tweaked (like rolling off highs above 12khz for bitrates this low...this frees up the limited number of bits to work harder in the MIDRANGE where the ear is most sensitive. Of the ten audible octaves, the one between 10 and 20khz is least important, ESPECIALLY for talk programming).

The "rock solid" applied TO THE ABILITY TO LOCK ONTO AND HOLD A DIGITAL SIGNAL. I've obviously never heard the specific stations Tom spoke of.