Why does sound volume drop when pic quality rises?

[Kermit power]

I've only got one 4K TV channel (BT Sport Ultimate) so I guess they might have just chosen to have the volume level lower than it is on standard HD channels, but I've noticed that in turn, the sound level on any given HD channel will be quieter than its SD sibling.

Does anyone know why this is the case?

[Murph7355]

I suspect it'll be something to do with the sound being surround sound, splitting across channels and poor control at the broadcast end.

Gets royally on my tits with HD channels at the moment, and my new fangled Sony TV has no way I'm aware of to compensate. The one last frustrating thing for me with my current set up (well, that and the fact that Sony's YouView implementation doesn't allow reminders to be set up or recording/live TV pause etc...the alternative being their own guide that aesthetically was done by 16yr old intern).

[jontykint]

Murph7355 said:

I suspect it'll be something to do with the sound being surround sound, splitting across channels and poor control at the broadcast end.

Gets royally on my tits with HD channels at the moment, and my new fangled Sony TV has no way I'm aware of to compensate. The one last frustrating thing for me with my current set up (well, that and the fact that Sony's YouView implementation doesn't allow reminders to be set up or recording/live TV pause etc...the alternative being their own guide that aesthetically was done by 16yr old intern).

There’s no PCM output option?
Should be if you aren’t using surround speakers

[Murph7355]

jontykint said:

There’s no PCM output option?
Should be if you aren’t using surround speakers

Ironically on the TV in question I am using surround

[Zirconia]

Have you set up the Youview box options? There will be video and audio options. Manual should explain. Cant remember what the output is if there is no surround.

I tend to only use mine for 5.1 on the rugby, hence don't bother with the rest. I use the BT TV app on the Apple TV for all the other stuff. I avoid SD if I can (not always possible).

Edit. Through the amp it is fine.

[TimeforTea]

My panasonic plasma/5.1 amp results in a reduced sound volume when watching a HD channel. Audio is fed via an optical link to amplifier not through HDMI. hope this helps

[Kermit power]

Having had the same issue on different TVs, different amps, different connections (Optical/HDMI) and watching different channels, I can only assume that for whatever reason, the transmission goes out somehow with a lower volume level, rather than it being anything "wrong" with my equipment.

I don't have the faintest idea why that is, though, so had hoped that there might possibly be someone on here from the broadcasting side of things who could enlighten me.

[JimbobVFR]

A Dolby or similar sound track will generally have a greater dynamic range which means the difference between the lowest and highest sound levels.

[Zirconia]

Kermit power said:

Having had the same issue on different TVs, different amps, different connections (Optical/HDMI) and watching different channels, I can only assume that for whatever reason, the transmission goes out somehow with a lower volume level, rather than it being anything "wrong" with my equipment.

I don't have the faintest idea why that is, though, so had hoped that there might possibly be someone on here from the broadcasting side of things who could enlighten me.

If I set my BT set top to stereo, it is louder than the set top set to surround (it is in settings). Dolby will have all the elements from the sharp end with metadata file on levels. Part of the Dolby spec. is the ability to downmix, I think the level difference is the down mix pulling what it thinks you want out of it giving you a Lt/Rt feed. I think the downmix levels are set at the sharp end.

e.g. from site there will be a PCM and Dolby. The PCM may contain commentary and fx. That will be fed into the Dolby at site then on to the studio. I don't know what happens after that but the same elements are in there and there will be a metadata file setting levels etc. Dolby version you get is not the same as the OB sends out. One is a professional set up the other consumer.

SD probably has the PCM fed to it. HD and UHD can have dolby but I expect that if the set top is set to stereo, it is pulling out the PCM. Dolby is passing the Dolby to the TV and the TV is downmixing.

I think. It was always embedded when it got to me and we checked for errors more than levels (well, lots of things).

Sound engineer will know.

[legzr1]

JimbobVFR said:

A Dolby or similar sound track will generally have a greater dynamic range which means the difference between the lowest and highest sound levels.

This.

I recently sorted out an Arcam soundbar for elderly parents. It’s a revelation compared to TV speakers but not exactly ‘hifi’ . When watching HD or 4K channels with DD they complained that ‘voices are quiet then it’s too loud with bangs and crashes’..
After failing to explain dynamics and the reasons behind it I selected an option on the Arcam which levels the sound giving almost zero dynamics and they love it.

I give up....

[Kermit power]

legzr1 said:

JimbobVFR said:

A Dolby or similar sound track will generally have a greater dynamic range which means the difference between the lowest and highest sound levels.

This.

I recently sorted out an Arcam soundbar for elderly parents. It’s a revelation compared to TV speakers but not exactly ‘hifi’ . When watching HD or 4K channels with DD they complained that ‘voices are quiet then it’s too loud with bangs and crashes’..
After failing to explain dynamics and the reasons behind it I selected an option on the Arcam which levels the sound giving almost zero dynamics and they love it.

I give up....

I'm with them on that!

It's great having all that dynamic range when you're watching a film in a soundproofed cinema, but a right pain in the arse if you're trying to watch something without disturbing kids who've gone to bed or pissing off the neighbours!

Fortunately, my amp has a setting which boosts the centre channel where most of the speech is, so I no longer have to choose between all the actors whispering or replacing all my windows after an explosion if the actors are talking normally!

[Zirconia]

Have you tried changing the audio settings? On the BT set top? There are two, one is stereo and one is surround.