Weird volume behaviour

[tonybonner]

The other night I stumbled into channel 57 (U&Eden) - not a channel I normally watch - while Kessler was on and it was VERY LOUD. So, I turned the volume down - or at least I tried to. The Humax volume bar went all the way
down to 0 but the sound remained VERY LOUD. I tried several other channels and the volume control behaved as expected then returned to ch57 and the problem remained. As I wasn't interested in the programme I moved on
and put it down to being 'one of those things'.
However , last night I thought I'd check again and there was still the same issue with Kessler on ch57. Haven't checked it at other times to see if ch57 is always like that but it seems pretty weird.

Just wondered if anybody else has experienced the same behaviour? Not overly-fussed about it - just curious.

 

[prpr]

Depends what channels you normally watch I suppose.
You have Digital Audio Output set to Multi-Channel in the Settings/Preferences/Audio menu and you have selected a service on PSB3.
This happens with all the HD channels, so I guess you don't watch any of them, and the three SD services thereon - namely 46 5SELECT, 57 U&Eden, 69 LEGEND XTRA.

 

[Black Hole]

From a long time ago (but nowhere near as long as we've known about this):

Here's what happens with HDR-FOX (may be the same with 5000T): if the audio preference is set to "multichannel" (ie surround sound), the audio feed output to HDMI is taken directly from the broadcast stream so as to preserve the surround sound information when the service is capable - ie a HiDef channel. The sound stream is accompanied by command codes to tell the TV (or whatever) what the volume control setting should be.

All StDef services, or all services (including HiDef) if the audio preference is set to "stereo", are converted to PCM for the HDMI output, and the PCM is scaled according to the volume setting.

This means that if the TV (or amp) is not capable of interpreting the volume commands, the HiDef services will be presented at full volume unless the audio preference is set to "stereo" (at which point you lose any surround sound). You have the choice of setting the volume using the TV (set the volume on the Humax to maximum), or settling for stereo.

Two work-arounds:

1. Set HDR-FOX audio to stereo not multichannel; or...

2. Set HDR-FOX volume to max and only control volume using the TV's remote.

 

[MymsMan]

2. Set HDR-FOX volume to max and only control volume using the TV's remote.

I do this and have also disabled the VOL buttons on the Humax remote incase I forget

 

[tonybonner]

Thanks for the responses - prpr nailed it in every respect. Box is set to multi-channel and I don't tend to watch those channels as reception for that mux is a bit more marginal than the others.
I used to have it set to stereo but recently got a new Panasonic Freely tv and messed around with various settings when setting everything up. I think I left on multi-channel as it seemed a better match for the new tv.
Audio for the tv is routed out to a soundbar so I can use the volume on that remote if I should want to watch one of these channels but SWMBO only uses the Humax remote. ;-)
No worries and thanks again for the quick answers/advice.

 

[Owen Smith]

Audio for the tv is routed out to a soundbar so I can use the volume on that remote if I should want to watch one of these channels but SWMBO only uses the Humax remote. ;-)

It is a huge pain that the Humax remote cannot be programmed to control the TV or soundbar or AVR volume by infrared when in PVR mode to control the HDR Fox T2. Why on earth can't it do such an obviously useful thing? Switching to TV or Audio mode isn't the same, it takes more button presses and a huge graphic appears on screen disrupting the picture showing the mode change.

 

[Luke]

a huge graphic appears on screen disrupting the picture showing the mode change.

For HDR-FOX T2s that have c/f installed the ir package adds an option for that to be suppressed.

 

[MymsMan]

It is a huge pain that the Humax remote cannot be programmed to control the TV or soundbar or AVR volume by infrared when in PVR mode to control the HDR Fox T2. Why on earth can't it do such an obviously useful thing? Switching to TV or Audio mode isn't the same, it takes more button presses and a huge graphic appears on screen disrupting the picture showing the mode change.

While we can use the ir package to remap the remote control keys that happens within the humax,
We have no way of changing the the codes generated by the Humax remote control to codes that the TV would see.

But if you were to use a programmable remote control you should be able to set it up so that the volume buttons did control the TV.

 

[Owen Smith]

For HDR-FOX T2s that have c/f installed the ir package adds an option for that to be suppressed.

Where is that? I don't recall seeing it.

 

[Black Hole]

Where is that? I don't recall seeing it.

WebIF >> Settings >> Setting for ir package >> Click here for options >> Block remote control mode change icons? = YES

Simples. Same place to disable volume controls (for those wanting to reserve volume adjustments to the TV).

 

[Owen Smith]

WebIF >> Settings >> Setting for ir package >> Click here for options >> Block remote control mode change icons? = YES

Simples. Same place to disable volume controls (for those wanting to reserve volume adjustments to the TV).

Thanks. I've never installed the IR package, and all previous discussion I've seen about it was for changing what functions are on which buttons of the remote which I have never wanted to do. I've never seen anything about it having these other features.

 

[prpr]

Block remote control mode change icons?

Presumably it blocks the actions and doesn't just stops the icons from appearing?
That would then seem to be better as "Block remote control mode changes".

I've never seen anything about it having these other features.

Perhaps you should be more curious.

 

[Luke]

Presumably it blocks the actions and doesn't just stops the icons from appearing?
That would then seem to be better as "Block remote control mode changes".

The ir package option does not stop the action being completed.
The action is to change the device mode on the remote. The option stops the change mode image being displayed by the HDR-FOX/HD-FOX if the remote does send any of the ir codes for the device buttons.

In the words of the original and first post that announced the ir package:

This package also adds the option to disable the on-screen notifications of remote control mode changes which appear with later Humax firmwares and newer remote controls. The option is under Web-If >> Settings >> Remote Control Settings >> Options >> (scroll down to) 'Block remote control mode change icons' >> On >> Then reboot the Humax.

 

[Owen Smith]

Perhaps you should be more curious.

Many years ago hummy.tv was so active and changes so frequent I couldn't keep pace and did not read everything. Now I'm playing catchup finding out what is possible.

 

[Black Hole]

I've never seen anything about it having these other features.

You can also use it to reassign buttons and create macros. IR has far more capability than just provide a virtual RC!

 

[Owen Smith]

You can also use it to reassign buttons and create macros. IR has far more capability than just provide a virtual RC!

Reassigning buttons and creating macros was what I thought it did. But I have no need of that so I never looked at the IR package.

 

[/df]

What I've found is that when using the Freeview multi-channel sound the volume can be out of balance between HD (perhaps DVB-T2 in fact) even within a single TV set (Sony 2013), the "HD" sound being significantly fainter, almost as if it had discarded the centre channel. No Humax kit involved yet.

With two set-ups involving HDx-Fox T2s, and

2. Set HDR-FOX volume to max and only control volume using the TV's remote.

I get low sound on "HD" channels unless the digital sound o/p is set to Stereo.

Case 1: HD-Fox T2 -- HDMI--> TV

Case 2: HDR-Fox T2 --Component video+optical audio--> Denon AV --HDMI--> TV

So what is the point of the multi-channel digital output?

Does it only work in some hypothetical broadcasting scenario where all channels have multi-channel sound?

Does the Stereo digital o/p contain encoded surround signals that the TV, for its virtual surround mode, in case 1 and the AV in case 2 should be able to decode? (According to BH's post quoted above, no).

In Stereo mode, the AV is only seeing PCM/L+R input according to its on-screen Info. In Multi-channel, it's Dolby Digital with 2/0/.0 or 3/2/.1 depending on content.

Also in case 2 (test: Corridors of Power E5, BBC 4 vs 4HD, ignoring full volume per quoted 2. above), apparently changing the Humax volume has no effect on the volume at all regardless of Stereo/Multi-channel. The only change is that Stereo causes the "HD" and non-"HD" volume to match while "HD" is at least 3dB down in Multi-channel. The AV Info menu reports "Offset -8dB" (no offset is shown for PCM; setting the AV's Source level adjustment for "Digital Inputs" to +12dB, reducing the master volume to compensate, brings the "HD"/non-"HD" closer, as I hear.

Is it possible that the volume commands sent by the Humax code are wrong or that there are competing versions of the spec?

 

[Black Hole]

Also in case 2 (test: Corridors of Power E5, BBC 4 vs 4HD, ignoring full volume per quoted 2. above), apparently changing the Humax volume has no effect on the volume at all regardless of Stereo/Multi-channel.

I don't understand that. In Stereo mode, the volume of the audio signal should be baked into the PCM output from the Humax.

 

[Owen Smith]

I run in multi channel mode and yes the audio volume is substantially lower for HD channels, always has been. I set my AV amp to about 50 volume to watch SD channels, whereas for HD channels (even when they're only broadcasting stereo sound) I set my AV amp to about 58 volume. Those numbers are roughly in db.

In Stereo mode, the AV is only seeing PCM/L+R input according to its on-screen Info. In Multi-channel, it's Dolby Digital with 2/0/.0 or 3/2/.1 depending on content.

That's how it's meant to work. ITV1 HD and C5 HD are always in 2.0, BBC HD channels and C4 HD are sometimes in 5.1.

The HD channels audio is broadcast as AAC which is actually stereo and then some difference channels to convert that to 5.1. The Humax transcodes that to Dolby Digital 2.0 or 5.1 at 640kbps (max for DD) when in multi channel mode. In stereo mode the Humax takes the AAC stereo, discards any conversion extras to 5.1, and converts the AAC stereo to LPCM (at which point any meta data like volume offset is lost).

The only change is that Stereo causes the "HD" and non-"HD" volume to match while "HD" is at least 3dB down in Multi-channel. The AV Info menu reports "Offset -8dB" (no offset is shown for PCM; setting the AV's Source level adjustment for "Digital Inputs" to +12dB, reducing the master volume to compensate, brings the "HD"/non-"HD" closer, as I hear.

The "Offset -8db" you are seeing matches almost exactly how much I have to turn the volume up for HD channels. The HDR Fox T2 has always been like this.

 

[Owen Smith]

So what is the point of the multi-channel digital output?

To get discrete 5.1 multi channel output when it is broadcast. And it does sound much better on my AV amp surround speakers than having the amp do a matrix surround decode (eg DTS Neural:X) of stereo audio.

Does it only work in some hypothetical broadcasting scenario where all channels have multi-channel sound?

No, it only works when the programme being broadcast has 5.1 sound.

Does the Stereo digital o/p contain encoded surround signals that the TV, for its virtual surround mode, in case 1 and the AV in case 2 should be able to decode? (According to BH's post quoted above, no).

Depends on what the stereo as broadcast contains. On SD channels the MPEG stereo audio can be Dolby Surround encoded. On HD channels the AAC stereo can be Dolby Surround encoded eg on ITV and C5 since they are stereo only. On the BBC and C4 stereo programmes might be encoded, and for 5.1 content that is supposed to be encoded in the stereo mix down and if you have multi channel output set then the extras channels to extract from the stereo should remove the surround encoding from the stereo (because it's part of the extra audio that now goes to the rear speakers in the 5.1 channels).

It is is all a lot more complicated than first appears.