H-K AVR 430 Strange Audio behavior via Optical input

[MrCreosote]

This has been a journey trying to troubleshoot Optical audio from a Hisense 55H7B 4k UHD to my 430. (I have already exchanged the TV and the replacement does the same thing.)

I've had DVD and BD players connected and have never had any audio issues - only with this TV.

My concern is that the TV is new (2015) and the 430 is pre-HDMI, i.e., old.

The symptom I get, I call LOOM (Left channel Only, Over Modulated) which occurs when:

1) The TV digital output is set to PCM
2) The TV digital output is set to RAW and apps like Netflix have Stereo audio (5.1 audio works correctly)

When in RAW, OTA works just fine.

But when in RAW and Stereo is being processed, this is what happens:

1) for maybe 1/2 second, the audio is correct,
2) there is silences for maybe 1/5 second,
3) LOOM

This process seems like the 430 detecting and choosing the correct surround processing.

I tried Pandora on this TV and while it did the same thing, the Over Modulation was incredibly high - had to run about -35db down on the 430 volume (-25db is typical requirement when LOOM), proper audio runs at 0db or higher.

It's Long Term Intermittent:

This happened when I first got the TV.
I subscribed to the Pandora app, and it went away!
I had a few days without issue.
I tried registering my TV with Youtube and LOOM!
Tried things and it went away again.
Left things alone and worked fine on Netflix for over a week.
Today went to OTA and when back on Netflix, LOOM!
and I'm stuck with LOOM for now...


Has my 430 ever had any issues? Yes.

1) Maybe a year ago, it would not turn on. Then after a couple weeks, it mysteriously did and has worked fine ever since. I did Resets, but that didn't have any effect. No idea how this problem disappeared.

2) Sometimes, the surround processor gets confused and the rear channels increase 10-15 db. Usually changing channels or processing makes this go away.

Firmware Upgrades? No.

I have a copy of what I think is the 1st one and never did it. I believe there are at least 2 of them, the latest being about 2009 maybe? (could very easily be wrong on that year)

Have not done it after reading of people bricking their unit. There was some talk about people trying to do the upgrade without the serial cable which I have bought for the job. H-K no longer offers the firmware files, so I would have to hunt around for the latest. But then regarding firmware: don't do it unless you have to.

I don't know if firmware could help matters.
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My Thoughts on the Matter:

My gut told me the replacement TV would behave the same way and it did.

My gut is telling me it could be the 430 - either do to age difference (incompatibility) or surround decoder problem.

The only thing I can think of is to snag a used, no more than 5 years old, AVR off Craigslist and see if I get the same problem. I don't have lots of money so everything is done on the cheap. I don't see any point in a 4k receiver and don't see why I can't use my TV as the video hub and an AVR like the 430, just to process the digital sound.

I would hope that Optical is highly compatible between devices, however, I'm starting to find all sorts of issues between devices, especially TVs and Soundbars. But these issues are not what I call malfunctions like One Channel or Over Modulation. They report OTA Optical output only, no pass through from HDMI, or 2.0 only - but some report "ticking" which I classify as a malfunction.

64$ QUESTION: Should I get another AVR? (If NO, what should I check?)

 

[wmgwizard]

Have you tried a different optical cable, or maybe even inverted it's orientation.

Do you have other optical sources you could try ?

 

[MrCreosote]

Yes, I've tried a different TosLink cable AND a different port in the 430.

Yes, I've tried other Optical Sources with no issues:

• Visio BD player - earlier model that does not handle 5.1 Netflix
• Toshiba DVD recorder

I've also tried (this was my previous config) a 1 year old Sony BD player but it had a Coax connection to the 430 - it worked just fine w/Netflix 5.1 (reason I bot it.)
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My "gut feeling" it's the 430 is based on the "Long Term Intermittent" characteristic. The 430 has already shown that when surround processor "gets confused" and the rears get super loud.

Just remembered, there was another 430 peculiarity: Netflix audio would drop out:

This would occur once of twice a week and would be related to a specific time point in the stream. The 430 would never recover it allowed to continue. Would have to pause the Netflix and then Off/On or change surround processing method to "get the 430 unstuck."

But this happened with the Sony BD via Coax and never occurred from the TV Optical.
​

_______________________

I was also trying to find reference to the 430 issue of circuit boards developing cracks. I distinctly remember coming across this modality when mine acted up and would not turn on (or was it would turn on and then off in 10 seconds.) I never had a chance to inspect and then 1-2 weeks later (I would try to turn it on every now and then), it turned on and was stable for no reason whatsoever.

 

[MrCreosote]

UPDATE New Weirdness:

INPUT = Youtube video from 1-year old Sony BD player and 430 shows 2 different PCM sampling rates depending on path:

48 kHz when HDMI (BD to TV), then Optical (TV to 430) w/distortion(propably over modulation) and poor freq. resp.

44.1 kHz when Coax (BD to 430) s/nice clean sound​

Is that even possible???

 

[whoaru99]

Yeah, can the AVR handle 48kHz?

Another thought...can you select/change the downsampling rate or other settings in the TV?

 

[MrCreosote]

There are no frequency selections available on the TV. But the DVD and BE players might possibly. But I can't see the BD outputting different samplings over Coax and HDMI.

Somewhere I ran across PCM rates of 44.1, 48, and 96kHz, so I was wondering if in the early days, perhaps devices were set up to handle 44.1 and 16 bit resolution (they were doing stuff like the Sony PCM-1??? that digitally encoded 2 channels of 4-channel so you could record 4-channel using the audio tracks and the Super VHS audio.)

There seem to be two protocols over Optical S/PDIF, something like AES3 and... what.... PCM? Don't remember.

With audio formats like DD+ exceeding bandwidths of S/PDIF, which are downconverted, there could be a whole new series of issues with the historically rock solid S/PDIF and Coax connects.

 

[whoaru99]

There are no frequency selections available on the TV. But the DVD and BE players might possibly. But I can't see the BD outputting different samplings over Coax and HDMI.

I can, because the HDMI systems talk to each other and can negotiate settings. Optical/Toslink is just a dumb connection, so to speak. It doesn't know what's on either end of the cable.

 

[MrCreosote]

So the HDMI may be upconverting from 44.1?

Does ARC negotiate or is it dumb?

It might be the AVR is not happy with the HDMI conversion that is then passed out the Optical. If the AVR had HDMI w/ARC, the issue may disappear.

If I decide to score a used HDMI AVR, it should have ARC. (I'd not attempt to get a 4k, HDCP 2.2 receiver. New ones have crappy amps in them and good ones are crazy expensive. My 430 weighs 39# so I guess that's why people still like them)​

 

[MrCreosote]

Check out this Sampling info on Wiki about PCM and their mention "....can be used on newer equipment..." There are also issues of LPCM -v- PCM.

I'm thinking my AVR only has issues with 48 kHz. But has never had issues with DVD audio from players including DTS which really kicks.

Here is the Wiki excerpt:

Standard sampling precision and rates
Common sample depths for LPCM are 8, 16, 20 or 24 bits per sample.[1][2][3][24]

LPCM encodes a single sound channel. Support for multichannel audio depends on file format and relies on interweaving or synchronization of LPCM streams.[5][25] While two channels (stereo) is the most common format, some can support up to 8 audio channels (7.1 surround).[2][3]

Common sampling frequencies are 48 kHz as used with DVD format videos, or 44.1 kHz as used in Compact discs. Sampling frequencies of 96 kHz or 192 kHz can be used on some newer equipment, with the higher value equating to 6.144 megabit per second for two channels at 16-bit per sample value, but the benefits have been debated.[26] The bitrate limit for LPCM audio on DVD-Video is also 6.144 Mbit/s, allowing 8 channels (7.1 surround) × 48 kHz × 16-bit per sample = 6,144 kbit/s.

There is a L32 bit PCM,[27] and there are many sound cards that support it.​

 

[MrCreosote]

Latest update: Appears could be the TV. Another person having similar problems claims unplugging the TV for 10 seconds restores correct functioning.

My experience has been everything works just fine for many days, and then I try some different source that "blows up" the surround and then it stays "blown up." This will continue for days and then mysteriously disappear. The last time it disappeared, there was a power outage very close to the time it mysteriously corrected itself.

What is worse is that it seems to be coming from youtube which is a collection of stuff people upload. Audio here can be completely butchered and corrupted and could cause havoc with devices expecting to see proper data streams. This could be another matter completely: "How to handle corrupted digital audio?"

 

[MrCreosote]

IT WAS THE TV!

Long story short:

If TV turned on and it comes up in the TV tuner, LOOM when watching non-5.1DD apps.

If TV turned on and it comes up in a HDMI input, everything is fine.

How to fix if LOOMing?

1. Select HDMI input,
2. Turn Off
3. Turn ON

FIXED!​

I'm happy because the H-K AVR 430 is a decent sounding AVR. Now I'll have to see if I'm brave enough to do a firmware update... I do have the serial cable to do it.

 

[whoaru99]

If you are going to do a firmware update and it's by serial I STRONGLY suggest using a real serial port, not USB serial adapter.

 

[MrCreosote]

Oh yessss.... I'll put my XP machines to good use! (now if I can only find that cable I specifically bot to do this job...)