Accurian "Processing" Delay on analog.

[clouseau]

Maybe this has been discussed here before but I had never heard of it.

The Accurian radio has a slight delay when receiving conventional analog FM signals. I first noticed it this morning, when I had the Accurian playing in the Dining room on analog FM and then decided to turn on the stereo in the living room to the same station.

The Accurian has that "Stadium Effect" which is a delay of between a tenth and a quarter second (I'd Guess). It still synchs up to the HD delay flawlessly so I guess it's designed that way.
I'd never noticed it before. Weird.

Clouseau

 

[R.F. Burns]

Is that the radio or the station? Due to the buffering scheme associted with compressed digital transmission, a delay is built into the analogue transmission so that the switch from analogue to digital is supposed to be nearly seamless. I'd suggest the stations delay settings are somewhat off. I've experienced the effect you are talking about on two different HD radios, both of which are from different manufacturers.

 

[clouseau]

It's the radio in analogue. it doesit on "ALL" stations even those without HD. It.s got nothing to do with the HD.

(Actually The HD and the analogue align fine.) Strictly an Analog issue.

I'm wondering if the radio actually "Digitizes" the analog signal as it goes to the audio amp or something.

Clouseau

 

[hipporadio]

Earlier discussions here have revealed that the Accurian does indeed rely on a DSP for general audio—regardless of radio reception mode. That chip may very well handle all the audio parameters—including EQ. Also consider the recent discovery that this product can decode and play C-QUAM AM stereo... I’m positive that the designers didn’t purposely add an old C-QUAM decoder chip just to be nice.

Since I do not own this radio—and remain uncompelled to buy it—I’m relying on the information posted by others here. This is obviously a product that utilizes a very few large-scale multi-function chips placed on a circuit board (keeping the cost low). That being that case, it’s also easy to speculate that a lower-performing audio DSP with above-average latency may be employed, thus creating the delay condition that you have observed.

 

[Demodave]

Every HD radio I've heard has this delay on while listening to analog signals. This is tru from the Accurian all the way up to the very expensive Day Sequerra HD Mod Monitor tuner. I believe that all HD radios are using DSP to process the RF signal. It's because of this that you find RDS and C-QUAM included too. It's all included in the DSP code.

 

[w9wi]

Every HD radio I've heard has this delay on while listening to analog signals. This is tru from the Accurian all the way up to the very expensive Day Sequerra HD Mod Monitor tuner. I believe that all HD radios are using DSP to process the RF signal. It's because of this that you find RDS and C-QUAM included too. It's all included in the DSP code.

I note that my Boston Acoustics HD receiver is able to reject HD sidebands and receive analog stations on the first-adjacent channel to a local HD station. (I'm 25 miles from the transmitters, you may not do so well if you're closer!) This radio also has the delay in analog signals. I'm sure it results from DSP of analog.

 

[Mike Walker]

The "processing delay" is because all audio passing through the Accurian, even through the analog input straight through to the headphone output with no equalization, is first digitized.

As for analog delay so that the analog signal is "in time" with the digital, this happens at the station, not in the radio.