HDMI vs Analog, Slight humming via HDMI

Ladies and Gentlemen,

Today I will go to the repair shop, to tell them the story, and to try and have the DVI monitor repaired.

If it is repaired I will repeat the setup to see if the PC-receiver HDMI setup will cause damage again.

If it does Ladies and Gentlemen of the electronics industry, then I have you by your BALLS, cause then I have proven that HDMI spec is somewhat FLAWED.

I was just thinking about the difference between Analog and HDMI experiment.

There was something else I NOTICED !

The HDMI connection to the receiver actually produces a SLIGHT HEARABLE HUMMING.

So there is apperently some voltage flowing into the receiver via the HDMI connection which is causing this.

This may seem irrelevant at first but it may actually be very significant.

My hypothesis is that this is the ETHERNET channel that is flowing over the HDMI connection, from laptop to receiver.

The laptop is sending ETHERNET packets over the HDMI cable... the receiver is expecting "audio return channel" packets, but instead receives ethernet packets.

Perhaps it is trying to interpret these packets as AUDIO packets and thus it produces HUMMING.

These are probably ETHERNET handshaking packets.

Very maybe it's possible to send RAW ethernet packets to the receiver with custom software.

In that case the HUMMING might be manipulated into sounding different, proving that this ETHERNET is indeed hearable on the denon 1909 receiver which is 1.3a HDMI.

GT 510 was 1.4 HDMI.

Today I will purchase GT 1030... HDMI unknown... will check later, but will probably not matter much.

IF YOU HATE HUMMING for whatever reason then HDMI is actually a DOWNGRADE HAHA.

FASCINATING ISNT IT.

Turning up the volume on the receiver will probably make the HDMI humming more NOTICEABLE.

Bye,
Skybuck.

wrote:
Ladies and Gentlemen,

Today I will go to the repair shop, to tell them the story, and to try and have the DVI monitor repaired.

If it is repaired I will repeat the setup to see if the PC-receiver HDMI setup will cause damage again.

If it does Ladies and Gentlemen of the electronics industry, then I have you by your BALLS, cause then I have proven that HDMI spec is somewhat FLAWED.

I was just thinking about the difference between Analog and HDMI experiment.

There was something else I NOTICED !

The HDMI connection to the receiver actually produces a SLIGHT HEARABLE HUMMING.

So there is apperently some voltage flowing into the receiver via the HDMI connection which is causing this.

This may seem irrelevant at first but it may actually be very significant.

My hypothesis is that this is the ETHERNET channel that is flowing over the HDMI connection, from laptop to receiver.

The laptop is sending ETHERNET packets over the HDMI cable... the receiver is expecting "audio return channel" packets, but instead receives ethernet packets.

Perhaps it is trying to interpret these packets as AUDIO packets and thus it produces HUMMING.

These are probably ETHERNET handshaking packets.

Very maybe it's possible to send RAW ethernet packets to the receiver with custom software.

In that case the HUMMING might be manipulated into sounding different, proving that this ETHERNET is indeed hearable on the denon 1909 receiver which is 1.3a HDMI.

GT 510 was 1.4 HDMI.

Today I will purchase GT 1030... HDMI unknown... will check later, but will probably not matter much.

IF YOU HATE HUMMING for whatever reason then HDMI is actually a DOWNGRADE HAHA.

FASCINATING ISNT IT.

Turning up the volume on the receiver will probably make the HDMI humming more NOTICEABLE.

Bye,
Skybuck.

That's a ground loop. You must have some analog audio
connected to the receiver, and the "selector" on your AV
receiver is currently selecting the analog audio.

If you flipped the selector to some other source, the
humming should stop.

Careful attention to ground loops can fix this. But
in a complex environment (exactly what AV receivers are
used for), sometimes these humming problems are unavoidable.

Radioshack used to make a "Hum Breaker", a device with
transformers for audio interconnect. The transformer bandwidth
was only 10KHz, but this was still considered "good", since
some inferior hum breakers only had a 3 to 4KHz bandwidth.
The transformer used in a hum breaker, must be wound
with extreme care, to avoid stray capacitance and other
parasitic effects.

An audio group or an AVForum, might have people skilled in
the removal of hum. They'd be better at it than I would be.

*******

Don't just go off and buy one of these. Try to fix the
problem some other way first. These can mess up the
sound, on the high frequencies, so they're a device of
last resort.

https://www.amazon.com/RadioShack-Sy.../dp/B002YGM5D8

Read the reviews for more than one model of "audio ground isolator",
to find one with a good passband (10KHz).

Using TOSLink between a device causing hum and the
receiver, would be another way to do it. But TOSLink
might not support enough channels. The plastic dental
fiber in a TOSLink, has no electrical path to conduct hum.

This example shows how a hum conduction path can be
broken with an optoisolator. Light shoots from one
side of the circuit to the other, without a ground
path being needed. You would need one instance of the
circuit for each channel in a 7.1 setup (8 circuit boards).

http://www.learnabout-electronics.or...rs/opto_53.php

Note that such a circuit idea is silly, in that the circuit
is not linear, and will cause a small amount of harmonic
distortion. There could be some "squaring" going on
in terms of the gain. A sine wave in, gives a distorted
sine wave out. Such a circuit must be carefully tested
by its author, with a tool like RightMark, to make
sure it isn't an analog disaster.

Paul

I found the source of the noise.

I have made a video comparing HDMI vs Analog.

https://youtu.be/7vfPUiGABwI

I tried out different settings.

And ultimately at the end of the video different audio processing options of the denon 1909 receiver.

For some strange reason audio processing is not available for the analog inputs, perhaps this is because HDMI is connected, when HDMI is disconnected maybe audio processing will become available again, not sure about that, will have to do a seperate test of that. (I will check manual too about this might be mentioned).

Anyway at the end of the video when playing around with last ninja music right before I switch to it I notice the "noise" on the speakers. It's maybe not hearable on the video unless maybe setting volume to max, but I do not recommend it for now, I may have to make a new video about this particular noise.

In the video at 13:36 and 13:40 you can see me switching to HDMI/HDP mode and that's when I notice the noise on the speakers (slightly).

I say: "Yeah"

(If you download video try playing it with windows media player, it's a bit faster than vcl media player for playing on low end systems).

I think I now know what/where this noise is coming from.

To re-produce the following steps have to be taken:

1. Switch to HDMI/HDP input

2. Have Auddyssey processing on

3. Have Dynamic EQ/Volume on.

What these "audio processing functions" do is:

They enhance "low volume sounds" which can be very cool especially in combination with 7 CH stereo for games like Warcraft Frozen Throne.

The AL/DirectX 3D sound positioning of the camera high above the battlefield will cause soft sounds like footsteps of soldiers or magic spells or creatures to be very soft/distant and basically not hearable on surround sound systems, maybe even stereo too.

What this denon 1909 receiver processing does, especially if in 7 ch stereo mode:

1. 7 ch stereo mode plays steroe on all channels, especiall sides and rear both basically.

2. The auddyssey processing and dynamic eq/volume further enhance low volume sounds and tune down high volume sounds.

So basically what is happening is:

Where there is no sound playing... apperently there is still a little bit of sound somewhere in the system... some voltages or signal might still be coming in over hdmi...

Maybe just sound from the universe or something.

And auddyssey/dynamic eq/volume picks up on this signal... maybe through fourrier transform techniques.

Or perhaps it's simply enhancing the noise in the denon receiver itself.

Somehow it's detecting a faint noise and basically boosting/enhancing it... which is ofcourse kinda weird.

Reminds me of tape casette decks and playing empty casette tape or something and basically playing noise ?!

Well that's my explanation at least for now.

Though I could do some further experimentation with this auddyssey and dynamic eq/volume and try and see what kind of noise this is by setting the volume really high.

Maybe it will pick up something interesting, ofcourse I shouldn't play any sound otherwise my ears getting blasted =D

Well at least this solves the mystery a little bit and I am not getting closer to solving/digging deeper into this mystery ! =D LOL.

Bye for now,
Skybuck.

^

Typo, I ment to write now, but I wrote not, a typo I frequently make.

Corrected:

Well at least this solves the mystery a little bit and I am now getting closer to solving/digging deeper into this mystery ! =D LOL.

(Or maybe I am never gonna get closer to anything lol, time will tell).

Description from/for youtube video:

"
In this video I try to find the source of the HDMI noise.

At 13:36 to 13:40 I notice it and I say: "yeah I hear the noise" something like that.

My explanation/hypothesis for this noise is as follows:

1. It's when HDMI/HDP input is selected.
and possibly
2. It's when auddyssey is ON.
and
3. It's when dynamic EQ/volume is ON

These are audio processing functions of the denon 1909 receiver.

These audio processing functions listen for weak signals in the audio HDMI input signals and ENHANCE then, low signals are increased in volume, loud signals are decreased in volume.

This can be nice for gaming, where weak signals might be unhearable because of 3D positioning/processing by game/directx/audio engines/camera positioning about battlefields like warcraft frozen throne.

Further enhancement can be done with 7 ch stereo playback, which sacrifices surround sound for massive increase in stereo sound, this will sound 2 channel stereo to all speakers.

For true surround sound direct 7.1 or multi ch should be selected, this great for games like World of Warships to hear sounds coming from certain directions and ofcourse for First Person Shooters like Quake, Wolfenstein and so forth.

(The right monitor is actually analog/vga too, it's remarkably sharp thx to it's auto config option in menu).

As far as I am concerned there is very little difference between HDMI and ANALOG audio quality.

The DACs are simply way too good. (Digital to Analog Convertors).

(Only advantage I see so far is more audio processing for HDMI on receiver side, perhaps unplugging HDMI might make this capability available for analog inputs too, not yet sure about that).
"

Bye for now,
Skybuck.