Why DSP Softmute?

[sunwave]

Both radios are the same radio except the ATS 20+ has a better encoder and FM BC filtering. They both use the Si4732-A10 DSP chip. This all-in-one solution has softmute. These are not the only radios utilizing softmute. C.Crane, Eton Elite Executive, and others using this series of DSP chips use softmute.

But for programming your ATS 20 or ATS 20+ you can disable softmute in your ino file. BUT beware. The Si4732-A10 will start to kick out a annoying "clapping" like sound! This is why we see all these DSP based radios softmuting. Experimenting with some ino files with softmute disabled then reflashing the radio with factory hex file introduced me to the difference in behavior. The chip is also a tiny bit slower changing bands while softmute is disabled.

This explanation is what brought me to the conclusion that sofmute is better than annoying "clapping" noise with every single detent rotating the encoder. It would be awful on radios made by CCrane, Eton, and Tecsun.

Just keep the original firmware intact or make a new ino file to re-arrange the display to your liking.

 

[Falcon9h]

Just why I'll never sell my older radios. Soft mute is the ebola of radio.

 

[Boombox]

They do it to try to decrease RFI and other noises that interfere with MW and SW reception. Some radios also have the variable bandwidth function (my Sangean HDR-16 has that on the AM band), where the bandwidth narrows when the signal weakens -- it's to reduce noise.

It sort of works. Sort of doesn't.... And it also is annoying. I only have one radio with actual DSP soft muting -- my Radio Shack AM-FM Pocket Radio.

The rest of my DSP chipped radios -- Grundig G2, Sangean PR-D18, PR-D5 and PR-D14 -- do not have any soft muting. And they all use similar SiLabs DSP chips.

So it's a feature that is not always 'switched on' the DSP chip.

 

[cherubim]

Soft mute can be disabled in some SiLabs chipsets. The Tecsun PL-880 for example has hidden settings that can, amongst other things, alter the soft mute threshold and enable DNR (auto bandwidth setting).

 

[sunwave]

Soft mute can be disabled in some SiLabs chipsets. The Tecsun PL-880 for example has hidden settings that can, amongst other things, alter the soft mute threshold and enable DNR (auto bandwidth setting).

Some SiLabs 473X series has a side effect after disabling softmute is a subtle but annoying "clapping" like sound each detent while turning the encoder when tuning the radio as per post #1. Do you want a side effect or soft mute? Can't have smooth tuning on Si 473x series dsp chips.
I have no Tecsun DSP radios. I suspect the DSP in the PL-880 might be a audio related DSP because the tuning is done by PLL Dual Conversion. see PL-880 | TECSUN Radio
That would be smooth tuning.

 

[Boombox]

Are we talking about actual soft muting (where the signal drops drastically once it goes beneath a certain threshold), or the normal muting between channels when one tunes the radio. Because they are two different things. Even PLL radios have muting in between channels as you tune. Soft muting occurs in DSP chips when you're listening to a frequency.

Some guys confuse soft muting with the capture affect one hears when the DSP resolves a signal.

 

[sunwave]

Are we talking about actual soft muting (where the signal drops drastically once it goes beneath a certain threshold), or the normal muting between channels when one tunes the radio. Because they are two different things. Even PLL radios have muting in between channels as you tune. Soft muting occurs in DSP chips when you're listening to a frequency.

Some guys confuse soft muting with the capture affect one hears when the DSP resolves a signal.

Let's not confuse any further. I am talking about tuning the radio. Just listening, while parked on a frequency, I do not find any evidence of soft muting. It is only when tuning the radio. My OP is about DSP based radios that do not use PLL synthesis. ATS 20/20+

It is upon tuning it chuffs that the chip is set to produce silence for each detent turning the encoder. We do not get the same smoothness of like a analogue PLL synthesized radio like the Sangean ATS 505 changing frequency.

 

[Boombox]

^^^^^^ Fair enough, so you're talking about regular muting, not 'soft muting', which is another, separate process. Cool.

Muting between channels has been around since PLL / Digital tuning, apparently to keep the user from hearing artifacts when the encoder is between channels. There are tons of mods to eliminate chuffing. I never saw the need for getting rid of chuffing, as it never bothered me.

RE: the ATS505: from what I understand, the early ATS-505s chuffed, the later ones (like the Radio Shack version that I have) didn't. My 505 sounds like tuning an old analog, non-digital tuner, with the main difference being that the stations / channels sort of pop in as you land on a frequency, or tune past one.