Bad audio quality SBS

[MrQuade]

I run my audio through my receiver and generally have Dolby Pro-logic enabled (movie mode) to upmix stereo to 5.1.

Just lately I've been noticing absolutely terrible audio quality on the centre channel when watching SBS. This has been particularly noticeable on recent episodes of Handmaid's Tale. Voices sound somewhat "crunchy" which doesn't help intelligibility.

I had a look at the bitrates and did notice that SBS's stereo is 192kbps whereas other broadcasters have been using slightly higher rates.

It's not so apparent on all shows. Perhaps it is just their stereo downmixer that is doing a poor job on some material?

Anyone else with a similar audio arrangement noticed this?

[peteru]

I had a look at the bitrates and did notice that SBS's stereo is 192kbps whereas other broadcasters have been using slightly higher rates.

192kbps stereo, even with MP3, should still be adequate for TV broadcasts.

It's not so apparent on all shows. Perhaps it is just their stereo downmixer that is doing a poor job on some material?

Almost certainly. None of the Australian broadcasters do even a half-reasonable job of maintaining reasonable levels of quality on what they broadcast. Audio, video, metadata, it's all < optimal. When Australia went digital, all the old school professionals retired or were "moved on". It's a shame, because the analogue grey-beards cared. I'm sure that there are still a few people out there that care, but they seem to be the exception and judging by what is being broadcast, those people don't get much say in how things get done.

Anyone else with a similar audio arrangement noticed this?

Sorry, can't verify.

Problem 1.
My Denon AVR blew the LDO VR on the digital board. At least that's my diagnosis. It's an obscure SHARP part that's hard to source and has a non-standard pinout, so I can't substitute parts. I'm contemplating building a completely separate circuit using a buck converter daughterboard and patching it in. However, given the current study load, exams and work load, that's still a few weeks away.

Problem 2.
Both my ears went bad earlier tonight. Right ear is -6dB at 14kHz and very sore, left one is -6dB at 18kHz and slightly uncomfortable. Normal hearing is usually -6dB at around 20-21kHz. (Yes, I can normally hear CRTs TVs when walking past people's houses.)

[peteru]

Just had an idea...

Can you compare T4, U4 and V2. Three different classes of drivers, three possible outcomes...

[MrQuade]

Can you compare T4, U4 and V2. Three different classes of drivers, three possible outcomes...

I'll have a crack. I've been noticing this on the U4.

[peteru]

Can you compare T4, U4 and V2. Three different classes of drivers, three possible outcomes...

I'll have a crack. I've been noticing this on the U4.

That's probably the worst model in terms of audio drivers. Try T4, it should be best, followed by T2 and T3 in that order. V2 is still an unknown quantity.

[MrQuade]

That's probably the worst model in terms of audio drivers.

I thought you might suggest that. I recall our conversation about the U4's driver situation and how the enhancements to the T4 audio wouldn't translate across.

[MrQuade]

In hearing the same effect on the T4 and V2.

I suspect this could be isolated to Handmaid's Tale itself. Bad conversion by SBS perhaps?

[sonicblue]

I've started noticing the audio on SBS 30 and 31 is quite bad too, on both T2 and a Tivo.

It sounds very "swishy", as if there is some compression artefacts with the higher frequencies.

It's noticeable on voices of a particular timbre, and also things like audience applause clapping.

It seems to affect some programs more than others.

My audio setup is stereo optical out of the TV into an Emotiva PT-100 DAC into a pair of JBL 305 monitor speakers.

I've also tried headphones directly into the TV and Emotiva and hear the same artefacts.

[sonicblue]

Channel 76 seems to have the same issue. I've observed this through 3 different DVB tuners and 3 different signal pathways in my equipment. The sound quality is like that of a low bitrate podcast. For example a high pitched female voice, Instead of being perfectly centered dual mono, has all this scratchy hissing distortion in stereo offset, almost like whispering. It's not on everything though, it seems to depend on the content.

[raymondjpg]

I've started noticing the audio on SBS 30 and 31 is quite bad too, on both T2 and a Tivo.

It sounds very "swishy", as if there is some compression artefacts with the higher frequencies.

It's noticeable on voices of a particular timbre, and also things like audience applause clapping.

It seems to affect some programs more than others.

My audio setup is stereo optical out of the TV into an Emotiva PT-100 DAC into a pair of JBL 305 monitor speakers.

I've also tried headphones directly into the TV and Emotiva and hear the same artefacts.

I don't know if this is relevant but I have just noticed that some SBS transport streams broadcast from Black Mountain Tower Canberra are carrying two audio channels. I only noticed it because I routinely mux .ts recordings into .mkv with MKVToolNix GUI which converts teletext to .srt subtitles (monochrome). Last time I did this (about a week ago) I did not see these two audio channels.

TSReader shows that as of this morning SBS One is carrying two MPEG1 Audio streams. SBS HD and SBS VICELAND HD have an MPEG1 Audio and an MPEG4 Audio stream, the latter described as Audio type: visual impaired commentary. Muxing two copies of an SBS HD recording from last night with one or other of the audio streams showed no difference in the material broadcast on those two streams. Possibly the MPEG4 Audio stream is designed to carry some visual impaired commentary eventually, just not yet.

SBS World Movies is still only carrying one MPEG1 Audio stream.

Possibly could be contributing to these reported audio issues, if like every other region, Canberra has been late to the party with audio updates in its TV broadcasts.

[exitguy]

I've started noticing the audio on SBS 30 and 31 is quite bad too, on both T2 and a Tivo.
It sounds very "swishy", as if there is some compression artefacts with the higher frequencies.
It's noticeable on voices of a particular timbre, and also things like audience applause clapping.
It seems to affect some programs more than others.
My audio setup is stereo optical out of the TV into an Emotiva PT-100 DAC into a pair of JBL 305 monitor speakers.
I've also tried headphones directly into the TV and Emotiva and hear the same artefacts.

Melbourne using a T2 with optical out to AVR. Noticed it a lot on Mastermind as they are using those pin on mikes, which could be the issue.
Got a new AVR and though it could be that, but all other stations are OK as well as other devices like BR/DVD Player, Foxtel IQ3 and Laptop.

[raymondjpg]

Melbourne using a T2 with optical out to AVR. Noticed it a lot on Mastermind as they are using those pin on mikes, which could be the issue.
Got a new AVR and though it could be that, but all other stations are OK as well as other devices like BR/DVD Player, Foxtel IQ3 and Laptop.

Mediainfo discloses that the MPEG4 Audio stream carried by SBS HD and SBS VICELAND HD is HE-AAC. I don't know how the T/U/V series handle that, I've never tried it. If with difficulty, then it might be exacerbated by particular pick up devices such as pin on mikes.

[Gully]

Mediainfo discloses that the MPEG4 Audio stream carried by SBS HD and SBS VICELAND HD is HE-AAC. I don't know how the T/U/V series handle that, I've never tried it. If with difficulty, then it might be exacerbated by particular pick up devices such as pin on mikes.

On my U4 I haven't had any problems with SBS HD or Viceland HD recordings which I do daily/weekly.

[MrQuade]

Just to be clear, the audio problems that I have noticed are not severe. But if you have a good quality HiFi system connected to the TV, then you will hear a distinct degradation of audio quality. It's like there is a low level underlying crunch of digital compression noise.

[raymondjpg]

On my U4 I haven't had any problems with SBS HD or Viceland HD recordings which I do daily/weekly.

Do you know if SBS HD or Viceland HD are pumping out dual audio streams in your neck of the woods? I think it's more likely than not given it would be a metropolitan transmitter.

[raymondjpg]

Just to be clear, the audio problems that I have noticed are not severe. But if you have a good quality HiFi system connected to the TV, then you will hear a distinct degradation of audio quality. It's like there is a low level underlying crunch of digital compression noise.

Is there any way to select an audio channel when viewing or recording in the T/U/V series, if more than one audio channel is broadcast? I couldn't see any options in settings or autotimers on a quick look at a U4.

[Grumpy_Geoff]

Do you know if SBS HD or Viceland HD are pumping out dual audio streams in your neck of the woods? I think it's more likely than not given it would be a metropolitan transmitter.

Yes in Perth -

[raymondjpg]

Yes in Perth -

I see an option to select audio track in a U4 through use of the Audio button on the remote. Is there some other way through settings to permanently make a selection for particular TV channels?

[MrQuade]

I see an option to select audio track in a U4 through use of the Audio button on the remote. Is there some other way through settings to permanently make a selection for particular TV channels?

MENU-Setup->TV->Automatic language->Prefer audio track stored by service

You can get to the same setting by pressing MENU from the Audio screen.

[raymondjpg]

MENU-Setup->TV->Automatic language->Prefer audio track stored by service

You can get to the same setting by pressing MENU from the Audio screen.

I see the MENU-Setup->TV->Automatic language->Prefer audio track stored by service thanks, but cannot find the "Audio screen". The next thing would be to work out how to store an audio track for a particular service. My thinking being that by avoiding HE-AAC one could possibly overcome any audio issues that may arise with that format. For example there is another post here that reports similar issues with channel 76, which I interpret as 7flix. A quick test recording this morning confirmed that the audio stream was HE-AAC.

[Gully]

Do you know if SBS HD or Viceland HD are pumping out dual audio streams in your neck of the woods? I think it's more likely than not given it would be a metropolitan transmitter.

Not sure why you would think that but yes I do have dual audio - MPEG and AAC-HE, here in Melbourne and it defaults to AAC-HE.

And as others have said, it is easier enough to access the audio menu and select which one or just toggle with the audio button. Pushing and holding ot brings up the audio menu

[raymondjpg]

Not sure why you would think that but yes I do have dual audio - MPEG and AAC-HE, here in Melbourne and it defaults to AAC-HE.

See my first post of today (above). It looks like dual audio has only just drifted into the ACT, like so many other "enhancements" already up and away in metropolitan areas. Interesting that it defaults to AAC-HE. Just quickly scanning this thread it may be that any issues arising with SBS audio may be more pronounced when played through AV receivers. Another possibility is differences between transmitters, although that would seem less likely.

[MrQuade]

but cannot find the "Audio screen". The next thing would be to work out how to store an audio track for a particular service. My thinking being that by avoiding HE-AAC one could possibly overcome any audio issues that may arise with that format.

By "Audio screen", I meant the pop-up that is displayed when you press the AUDIO button. Just open the pop-up and press MENU.

As for "storing" the setting, it's supposed to just remember the audio track that you selected when you last visited the service. If it doesn't, then it means the feature pass probably not working as expected.

[prl]

Two of the Canberra SBS channels have two audio streams:
SBS HD MPEG (English), AAC-HE (aus)
SBS Viceland HD MPEG (English), AAC-HE (aus)

The rest have one:
SBS MPEG (English), MPEG (aus)
SBS World Movies MPEG (English)
SBS Food MPEG (English)
NITV Food MPEG (English)

[MrQuade]

And as others have said, it is easier enough to access the audio menu and select which one or just toggle with the audio button. Pushing and holding ot brings up the audio menu

Other way round. A short press currently opens the menu. When PeterU did it that way round I argued for a short press to toggle.

[raymondjpg]

By "Audio screen", I meant the pop-up that is displayed when you press the AUDIO button. Just open the pop-up and press MENU.

As for "storing" the setting, it's supposed to just remember the audio track that you selected when you last visited the service. If it doesn't, then it means the feature pass probably not working as expected.

It might be worth trying to select MPEG audio for the SBS channels streaming dual audio, and see if that overcomes any sound quality issues, particularly if with those channels audio defaults to HE-AAC.

[exitguy]

It might be worth trying to select MPEG audio for the SBS channels streaming dual audio, and see if that overcomes any sound quality issues, particularly if with those channels audio defaults to HE-AAC.

OK, all fixed - went through all the channels and found SBS to be the only one that has Dual Audio with MPEG and HE-AAC on some of the LCN, changed all to MPEG and tonight Mastermind audio was as previously. Looks like HE-AAC is the culprit !!!

[Gully]

See my first post of today (above). It looks like dual audio has only just drifted into the ACT, like so many other "enhancements" already up and away in metropolitan areas. Interesting that it defaults to AAC-HE. Just quickly scanning this thread it may be that any issues arising with SBS audio may be more pronounced when played through AV receivers.

I am playing back through an AV receiver so not causing problems here as I said (sorry I should have mentioned that before.

[Gully]

Other way round. A short press currently opens the menu. When PeterU did it that way round I argued for a short press to toggle.

Sorry, you are right. I use the subtitle and that is the other way round which is confusing.

[raymondjpg]

I am playing back through an AV receiver so not causing problems here as I said (sorry I should have mentioned that before.

Is your AV receiver deploying some kind of audio channel mixing e.g. Prologic II or is it maintaining audio channel integrity with stereo signals from the BW i.e. sound coming from just the left and right speakers? It's possible that the issue arises from mixing to a centre speaker.

[Gully]

Is your AV receiver deploying some kind of audio channel mixing e.g. Prologic II or is it maintaining audio channel integrity with stereo signals from the BW i.e. sound coming from just the left and right speakers? It's possible that the issue arises from mixing to a centre speaker.

It does mix, it is a Dolby Atmos Receiver, obviously not for this DTS Neural:X

[raymondjpg]

It does mix, it is a Dolby Atmos Receiver, obviously not for this DTS Neural:X

My question is more does it mix stereo to a central speaker? If it does, then perhaps the fact you don't notice the issue and others do might be due to which PVR you are using. As peteru said (above):

Just had an idea...

Can you compare T4, U4 and V2. Three different classes of drivers, three possible outcomes...

[Gully]

It does mix, it is a Dolby Atmos Receiver, obviously not for this DTS Neural:X

My question is more does it mix stereo to a central speaker? If it does, then perhaps the fact you don't notice the issue and others do might be due to which PVR you are using. As peteru said (above):

Just had an idea...

Can you compare T4, U4 and V2. Three different classes of drivers, three possible outcomes...

Definitely doesn't just mix to the centre speaker, I get sound from all speakers. And sure it might be different for differnt models, but I can only post on the U4.

[raymondjpg]

Definitely doesn't just mix to the centre speaker, I get sound from all speakers. And sure it might be different for differnt models, but I can only post on the U4.

OK I see what you are saying. I wasn't asking if it only mixed to a centre speaker, just whether in the mode operating in the AV receiver it (among other things) mixed to a centre speaker. Prologic II on my receiver delivers audio signals to L/R/C/LS/RS but not LFE. The only mix is to the centre speaker.

The question posed by peteru was directed to MrQuade and continues a longer standing discussion about audio enhancements. I could stand corrected but my recollection is that enhancements were made for the T3 and T4 but not for the T2 or U4 (and I guess subsequently the V2). I don't know if these enhancements ever made it to release firmware, or whether they might or might not have any bearing on the audio issue at hand. I am however of the view that for some (at least) of the T/U/V series of PVRs the evidence would suggest that there may be some issue with processing of HE-AAC audio which manifests as distortion when mixed to a centre speaker. I haven't seen any consumer grade AV receivers capable of decoding AAC audio and AFAIK they all rely on source devices like the BW PVRs decoding to PCM which when passed to the AV receiver may be processed either as discrete channels, or according to surround modes as set in the receivers.

[Gully]

Not sure if there was a question in there but on my system, yes the signal is PCM stereo (looking at Viceland HD) and it gets mixed to all channels including centre, all surround, subwoofer, etc.

[raymondjpg]

Not sure if there was a question in there but on my system, yes the signal is PCM stereo (looking at Viceland HD) and it gets mixed to all channels including centre, all surround, subwoofer, etc.

No question, just clarification. With Prologic II as far as I can tell on my Yamaha 5.1 receiver the only channel carrying mixed audio from L and R channel sources is the centre channel. LS and RS may be utilising out of phase signals from the L and R sources, but these would be different from mixed signals from L and R in the centre speaker. The LFE (single) channel is not being fed. If the audio issue being addressed here is due to mixing L and R sources then under these circumstances it would only be evident from the centre speaker. As this speaker is literally front and centre to any surround sound system then it might be prominent enough to appear to come from all front speakers.

I can't speak to what processing mode you are using with your Dolby Atmos Receiver but I doubt it would be very much different from my more modest Yamaha Dolby/DTS receiver when it comes to processing stereo sources.

[MrQuade]

I also want to point out, that I don't hear this on all content.

The one that was originally grating on me was the Handmaid's tale.

The audio from this wad presumably downscaled to a Pro-logic matrix from a 5.1 master, compressed to AAC, broadcast, and then decoded at my end by a Pro-logic enabled receiver.

In day to day viewing, I haven't been as aware of any issues, and tis might be due to the fact that these probably come from a 50Hz sourced stereo master.

Could be lots of things.

If I still have recordings of Handmaids tale and can find a particularly bad clip, I might be able to post it as an example.

[raymondjpg]

I also want to point out, that I don't hear this on all content.

The one that was originally grating on me was the Handmaid's tale.

The audio from this wad presumably downscaled to a Pro-logic matrix from a 5.1 master, compressed to AAC, broadcast, and then decoded at my end by a Pro-logic enabled receiver.

In day to day viewing, I haven't been as aware of any issues, and tis might be due to the fact that these probably come from a 50Hz sourced stereo master.

Could be lots of things.

If I still have recordings of Handmaids tale and can find a particularly bad clip, I might be able to post it as an example.

My last recording of The Handmaid's Tale was from SBS ONE HD 15-08-2019, but at that time in the ACT SBS ONE HD only had one MPEG Audio (MP2) audio channel so I can't check for any HE-AAC associated anomalies on that. However I can assure you that it was only stereo and I would be very surprised if SBS ONE HD broadcast in your area would have been anything else.

[MrQuade]

My last recording of The Handmaid's Tale was from SBS ONE HD 15-08-2019, but at that time in the ACT SBS ONE HD only had one MPEG Audio (MP2) audio channel so I can't check for any HE-AAC associated anomalies on that. However I can assure you that it was only stereo and I would be very surprised if SBS ONE HD broadcast in your area would have been anything else.

Yes, it would have been stereo, but matrixed 5.1 Pro-Logic.

[raymondjpg]

Yes, it would have been stereo, but matrixed 5.1 Pro-Logic.

Is there any way to confirm that? There are apocryphal references to Pro-Logic being incorporated in stereo streams, but from ten years or so back, and suggestions that SBS HD discontinued multi channel broadcasting when VICELAND HD was introduced. I'd be interested to see technical specifications for all TV audio broadcasts in Australia.

[MrQuade]

I don't have documented reference as such, but I can absolutely confirm that some content is encoded with deliberate centre and rear content. When the surround channels engage in proper context, is a very good sign.

They're is practically no reason why anyone wouldn't downmix a multi channel source to pro-logic, so I don't see why they wouldn't.

[Star6key]

I must be one of the few people who hates all of this multi speaker tv audio output. Left/right/centre is good enough (and even then, I would prefer just centre).

[sonicblue]

76 (7Flix) here in Adelaide has mpeg only and still suffers the issue on both my TiVo and T2.

Still in the process of evaluating SBS's mpeg track. Hard to tell as sometimes it appears to be in the source (eg international news bulletins).

[stevebow]

Two of the Canberra SBS channels have two audio streams:
SBS HD MPEG (English), AAC-HE (aus)
SBS Viceland HD MPEG (English), AAC-HE (aus)

The rest have one:
SBS MPEG (English), MPEG (aus)
SBS World Movies MPEG (English)
SBS Food MPEG (English)
NITV Food MPEG (English)

Heck, I was wondering where the female commentary was coming from the other night watching Tony Robinson's Britain's Cathedrals! Just checking, yes, Sydney's SBS audio config is the same as Canberra's.

[tomw]

I have been getting squeaky sounds with Canberra SBS Viceland recently on my TiVo. After reading this thread, I tried the alternate audio channel, and that fixed the problem. Thanks.

[MrQuade]

I noticed something amusing last night. The Rocky Horror Picture Show had an alternate audio track on the aac stream that included a descriptive voicover for the visually impaired. I've not seen that on any other event to date.

[raymondjpg]

I noticed something amusing last night. The Rocky Horror Picture Show had an alternate audio track on the aac stream that included a descriptive voicover for the visually impaired. I've not seen that on any other event to date.

TSReader shows that as of this morning SBS One is carrying two MPEG1 Audio streams. SBS HD and SBS VICELAND HD have an MPEG1 Audio and an MPEG4 Audio stream, the latter described as Audio type: visual impaired commentary. Muxing two copies of an SBS HD recording from last night with one or other of the audio streams showed no difference in the material broadcast on those two streams. Possibly the MPEG4 Audio stream is designed to carry some visual impaired commentary eventually, just not yet.

[IanSav]

Hi All,

Just to add to the discussions here but today when performing one of my diagnostic scans I have noted that the ABC, like SBS, is now broadcasting optional audio tracks here in Melbourne.

Regards,
Ian.

[raymondjpg]

Hi All,

Just to add to the discussions here but today when performing one of my diagnostic scans I have noted that the ABC, like SBS, is now broadcasting optional audio tracks here in Melbourne.

Regards,
Ian.

Yep, same in the ACT, with what looks like a second "Audio type: visual impaired commentary" MPEG2 AAC audio stream on all ABC TV channels except ABC which has two MPEG1 audio streams. Not so when I looked a couple if days ago.

As an aside 9HD Canberra is still broadcasting 6ch AC3. There's hope yet!