Poor Dynamic Range - Even with Full enabled

[Snoopy4]

So I played with this a bit, plus there was an update to 9.1.1 so I'm not sure which worked.

In settings:

Surround Sound (Auto)
Reduce Loud Sounds (Off)
Navigation Clicks (Off)

Either shutting the above off or the update seems to have improved the dynamic range. Can someone else check this and confirm? I was watching a movie at -30 and my wife stomped on the floor for me to take it down a notch. I used to set it on -30 when I wanted it to be quiet.
[doublepost=1454040042][/doublepost]

I am confused. Can someone confirm if its best to leave the audio to "Auto" (where I get PCM output) or "Surround" (where i seem to get DD output)? Thanks.

Typically auto. I believe the options are "Auto" and "Dolby Digital" and "Stereo".

 

[geesus]

So I played with this a bit, plus there was an update to 9.1.1 so I'm not sure which worked.

In settings:

Surround Sound (Auto)
Reduce Loud Sounds (Off)
Navigation Clicks (Off)

Either shutting the above off or the update seems to have improved the dynamic range. Can someone else check this and confirm? I was watching a movie at -30 and my wife stomped on the floor for me to take it down a notch. I used to set it on -30 when I wanted it to be quiet.
[doublepost=1454040042][/doublepost]

Typically auto. I believe the options are "Auto" and "Dolby Digital" and "Stereo".

Could just be because you are watching a different film? I find they do tend to vary drastically. I've tried setting all the audio menu sounds music etc to 'OFF' and not noticing any difference switching between them, when watching the same film.
[doublepost=1454089848][/doublepost]BTW have you maybe changed your surround mode from 'AUTO' to 'Dolby Surround' - that makes drastic differences to my audio with a LOT deeper bass in Dolby mode. Very odd how different receivers seem to react differently to this setting. It is massively more dynamic to my ears any way.

 

[JeffPerrin]

That wouldn't explain why the exact same movie played through an ATV 3 sounds better/more dynamic.

It may have been mentioned earlier, but the ATV3 is just passing the Dolby ac3 track on to the receiver for decoding (referred to by others as "passthrough"). With the new ATV 4 gen, the ATV itself is now doing the decoding onboard and passing the resulting audio as raw PCM down to the receiver**. After many hours working to port my own surround content over to the ATV 4, I've noticed several things happening to this processed audio:

1. Overall output is lower compared to the same track output from the ATV3. (not a big deal in and of itself...)

2. Subtle compression is being applied to the audio (even with "reduce loud sounds" off), resulting in the potential loss of dynamic range (the amount of compression varies with content).

3. Perceived reduction of audio quality. (Musical content seems to lack the "punch" and "clarity" when compared to the ATV3.)

Original master recordings were used to directly compare the side-by-side output from both the ATV3 and 4 gen models.

Anyway, I hope this helps clear up a bit of the confusion with how the ATV4 currently processed Dolby tracks, as well as encourages users to send feedback to Apple about improving the surround sound audio quality for the new Apple TV.

Jeff

*Bug reports were primarily focused on provable "unwanted compression". Audio quality is more subjective in nature and thus, can be difficult to quantify in a bug report...

** EDIT: If you select "Dolby Surround" in the ATV Audio settings, the ATV will (apparently) encode the processed audio back and output a new Dolby Digital stream.

//

 

[Snoopy4]

Could just be because you are watching a different film? I find they do tend to vary drastically. I've tried setting all the audio menu sounds music etc to 'OFF' and not noticing any difference switching between them, when watching the same film.
[doublepost=1454089848][/doublepost]BTW have you maybe changed your surround mode from 'AUTO' to 'Dolby Surround' - that makes drastic differences to my audio with a LOT deeper bass in Dolby mode. Very odd how different receivers seem to react differently to this setting. It is massively more dynamic to my ears any way.

That's interesting. Will try that.

 

[geesus]

It's very strange but changing that setting does more than it is letting on. e.g. since changing it, even when using Infuse, which passes through DD and DTS, the sound is different, when it shouldn't be. Setting it to Dolby Surround changes the dynamics drastically in all apps. I do only have a 5.1 set-up, so I resume that the LPCM 7.1 track was causing problems with my Yamaha amp somehow, maybe because of the 2 missing speakers. Either way, something is fundamentally wrong with that setting. I'm happier for now anyway.

Also, even with it set to Dolby Surround, it still plays back music in PCM 2.0, which strikes me as strange.

 

[priitv8]

With the new ATV 4 gen, the ATV itself is now doing the decoding onboard and passing the resulting audio as raw PCM down to the receiver.

If that is really the case, does it mean then, that my Sony is cheating on me, if it displays genuine DD 3/2.1 stream, not raw PCM??
When playing music, I see Linear PCM (this stream is probably manipulated by aTV during HomeSharing playback, as the source is 320kbps MP3):

When playing a movie with AC3 track, I see DD 3/2.1, 640kbps, 48kHz, DN=31:


I have to admit, I have a TV set inbetween (aTV-HDMI-Bravia-TOSLINK-AVR), and it may also manipulate the stream in transit. Most def, it won't pass DTS through.
[doublepost=1454155075][/doublepost]

Also, even with it set to Dolby Surround, it still plays back music in PCM 2.0, which strikes me as strange.

It sounds as proper to me. Would you want to receive your music as a re-encoded AC3 surround sound? Actually, not long time ago, that was precisely a bug in tvOS which has been fixed. Music was played back (but only in Computers app, not in Music app!) as 5.1 surround stream with only front L and R channels carrying any sound, others were just silent.

 

[geesus]

If that is really the case, does it mean then, that my Sony is cheating on me, if it displays genuine DD 3/2.1 stream, not raw PCM??
When playing music, I see Linear PCM (this stream is probably manipulated by aTV during HomeSharing playback, as the source is 320kbps MP3):
View attachment 613335View attachment 613340
When playing a movie with AC3 track, I see DD 3/2.1, 640kbps, 48kHz, DN=31:
View attachment 613336 View attachment 613337 View attachment 613338 View attachment 613339

I have to admit, I have a TV set inbetween (aTV-HDMI-Bravia-TOSLINK-AVR), and it may also manipulate the stream in transit. Most def, it won't pass DTS through.
[doublepost=1454155075][/doublepost]It sounds as proper to me. Would you want to receive your music as a re-encoded AC3 surround sound? Actually, not long time ago, that was precisely a bug in tvOS which has been fixed. Music was played back (but only in Computers app, not in Music app!) as 5.1 surround stream with only front L and R channels carrying any sound, others were just silent.

No, no, it is exactly how I want it to be. It didn't act that way previously, but as you say, was a bugged feature before. I'm not convinced that it is fixed now! Watching an old file now in Infuse, which was encoded using MP3 2.0 - if it follows that if my audio is being properly treated, then why is the ATV4 decoding that into Stereo Dolby Digital? Shouldn't that be being pumped out as PCM 2.0 too? How does it know it is film audio and not just music, seeing as it is an MP3 it could be both.

 

[priitv8]

Watching an old file now in Infuse, which was encoded using MP3 2.0 - if it follows that if my audio is being properly treated, then why is the ATV4 decoding that into Stereo Dolby Digital? Shouldn't that be being pumped out as PCM 2.0 too? How does it know it is film audio and not just music, seeing as it is an MP3 it could be both.

So far I am really confused where this multichannel PCM discussion started. As I am trying to prove, my aTV 4 outputs AC3 tracks as AC3-encoded, never see anything PCM.
I only see PCM while listening to stereo music or stereo AAC tracks.

 

[geesus]

So far I am really confused where this multichannel PCM discussion started. As I am trying to prove, my aTV 4 outputs AC3 tracks as AC3-encoded, never see anything PCM.
I only see PCM while listening to stereo music or stereo AAC tracks.

It's the most confusing audio configuration I have seen on *any* device I've ever owned, and I'm becoming increasingly frustrated with it tbh. Some of the features Apple choose to include, and others they omit stagger the mind e.g. why even have the option to 'Disable Siri' in there at all, considering you have to press a button to even activate it anyway!? Then they leave out 24Hz video playback, and no audio pass-through - two options that have been on every device I've ever owned, including cheap £20 media players from China. It truly blows my mind that they would leave two media critical features such as these out.

Back to audio, I wonder again if some receivers just react differently. Even if I feed mine an AC3 signal, my receiver reports it as a PCM source, even when my Apple TV is set to output Dolby lol

The audio set-up on this device is a hopeless mess.

 

[priitv8]

There is one area, that I've been constantly overlooking thus far - the EDID!
Because HDMI provides means for the source and sink to negotiate supported formats, aTV 4 may freely make different decisions when it meets proper AVR on the other end. Connected to my TV, it can only select between the formats that my device supports:
-----------------------------------------------------
------------ EXTENSION EDID BLOCK 1 ---------------
-----------------------------------------------------

CEA-EXT: CEA 861 Series Extension:
----------------------------------
Revision:..............................3
First DTD block at offset..............62
Display Supports:
overscan
basic audio
YCbCr 4:4:4
YCbCr 4:2:2

Data Block Collection:......#1 - Type 2
Video Type: standard CEA Timings
#1: 1920 x 1080p @ 50Hz - 16:9 - '1080p50' is not native (31)
#2: 1920 x 1080p @ 59.94/60Hz - 16:9 - '1080p' is not native (16)
#3: 1920 x 1080i @ 50Hz - 16:9 - '1080i25' is not native (20)
#4: 1920 x 1080i @ 59.94/60Hz - 16:9 - '1080i' is not native (5)
#5: 1280 x 720p @ 50Hz - 16:9 - '720p50' is not native (19)
#6: 1280 x 720p @ 59.94/60Hz - 16:9 - '720p' is not native (4)
#7: 720 x 576p @ 50Hz - 16:9 - '576pH' is not native (18)
#8: 720 x 576p @ 50Hz - 4:3 - '576p' is not native (17)
#9: 720(1440) x 576i @ 50Hz - 16:9 - '576iH' is not native (22)
#10: 720(1440) x 576i @ 50Hz - 4:3 - '576i' is not native (21)
#11: 720 x 480p @ 59.94/60Hz - 16:9 - '480pH' is not native (3)
#12: 720 x 480p @ 59.94/60Hz - 4:3 - '480p' is not native (2)
#13: 720(1440) x 480i @ 59.94/60Hz - 16:9 - '480iH' is not native (7)
#14: 720(1440) x 480i @ 59.94/60Hz - 4:3 - '480i' is not native (6)
#15: 1920 x 1080p @ 23.98/24Hz - 16:9 - '1080p24' is not native (32)
#16: 1280 x 720p @ 23.98/24Hz - 16:9 - '720p24' is not native (60)
#17: 640 x 480p @ 59.94/60Hz - 4:3 - 'DMT0659' is not native (1)

Data Block Collection:......#2 - Type 1
Audio Type Block
Supported format: Linear Pulse Code Modulation (LPCM), on 2 channels
Supported freq: 32kHz, 44kHz, 48kHz,
Supported bit depth: 16 bit, 20 bit, 24 bit,
Supported format: AC-3, on 6 channels
Supported freq: 32kHz, 44kHz, 48kHz,
Maximum bitrate: 640kHz


Data Block Collection:......#3 - Type 4
Speaker allocation data block
Rear Left Center / Rear Right Center not present
Front Left Center / Front Right Center not present
Rear Center not present
Rear Left / Rear Right not present
Front Center not present
LFE not present
Front Left / Front Right present
Front Center High not present
Top Center not present
Front Left High / Front Right High not present

 

[JeffPerrin]

If that is really the case, does it mean then, that my Sony is cheating on me, if it displays genuine DD 3/2.1 stream, not raw PCM??

Sorry, I was talking about the "Auto" settings resulting in outputting PCM. If you select "Dolby Surround" in the ATV Audio Settings, apparently the ATV will still apply signal processing to the audio and spit out* a "new" Dolby ac3 track, and is likely why your Sony reports the DD stream. There is no ac3 passthrough option on the ATV 4 gen.

*excuse my rough terminology while we await official documentation or statement regarding the Apple TV 4's audio DSP...

 

[priitv8]

Sorry, I was talking about the "Auto" settings resulting in outputting PCM. If you select "Dolby Surround" in the ATV Audio Settings, apparently the ATV will still apply signal processing to the audio and spit out* a "new" Dolby ac3 track, and is likely why your Sony reports the DD stream. There is no ac3 passthrough option on the ATV 4 gen.

*excuse my rough terminology while we await official documentation or statement regarding the Apple TV 4's audio DSP...

Nope, I have it on Auto. But now checking my telly's EDID, I can see why I only ever see 2-channel PCM and 6-channel AC3. That's all my TV set supports! If you connect aTV directly to a late AVR via HDMI, the negotiated formats may be different.

 

[JeffPerrin]

Nope, I have it on Auto. But now checking my telly's EDID, I can see why I only ever see 2-channel PCM and 6-channel AC3. That's all my TV set supports! If you connect aTV directly to a late AVR via HDMI, the negotiated formats may be different.

Interesting. Then you're likely still getting a processed AC3, just as if you had selected "Dolby Surround".

 

[kagharaht]

Sorry, I was talking about the "Auto" settings resulting in outputting PCM. If you select "Dolby Surround" in the ATV Audio Settings, apparently the ATV will still apply signal processing to the audio and spit out* a "new" Dolby ac3 track, and is likely why your Sony reports the DD stream. There is no ac3 passthrough option on the ATV 4 gen.

*excuse my rough terminology while we await official documentation or statement regarding the Apple TV 4's audio DSP...

Thats the rub for us with mid-high end AV setups. ATV4 is processing its own DD AC3 track improperly. Where the dynamic range is massively reduced. Watch the intro on Tomorrowland where the Fireworks Explosion and rocket flyby happens. The deep bass of the explosion and rocket rumble is missing. Yes there is some bass, but stick the ATV3 there or use Auto on ATV 4, multichannel and you can feel the difference. Problem with Auto/Multichannel is that if you have a 7.1 system, two of the speakers are silent. The AV Receiver cannot process the sound to apply PLX II, EX or even DTS 7.1 to all your speakers. Two will always be dead silent.

That and the continuing random jerkiness of movies streamed directly from iTunes Home Sharing Library. It just randomly becomes jerky even after the movie has already loaded into ATV4.

Ridiculous Apple.

 

[Colonel Badger]

Thats the rub for us with mid-high end AV setups. ATV4 is processing its own DD AC3 track improperly. Where the dynamic range is massively reduced. Watch the intro on Tomorrowland where the Fireworks Explosion and rocket flyby happens. The deep bass of the explosion and rocket rumble is missing. Yes there is some bass, but stick the ATV3 there or use Auto on ATV 4, multichannel and you can feel the difference. Problem with Auto/Multichannel is that if you have a 7.1 system, two of the speakers are silent. The AV Receiver cannot process the sound to apply PLX II, EX or even DTS 7.1 to all your speakers. Two will always be dead silent.

That and the continuing random jerkiness of movies streamed directly from iTunes Home Sharing Library. It just randomly becomes jerky even after the movie has already loaded into ATV4.

Ridiculous Apple.

Wait, so you're saying that Auto/a la PCM is giving you the full dynamic range vs the Surround Sound option on an ATV 4, comparable to an ATV 3?

That's new info. So far I was unaware of anyway to get the sound quality of the ATV 3 out of an ATV 4.

Theory; given the EDID thoughts above perhaps those that are happy with the sound are those using Auto with their receiver receiving a PCM feed. Those of us using either Surround Sound or Auto where their receiver is requesting DD 5.1 via EDID are getting poorer quality because the ATV 4 is re-encoding the stream.

 

[Rigby]

Thats the rub for us with mid-high end AV setups. ATV4 is processing its own DD AC3 track improperly. Where the dynamic range is massively reduced. Watch the intro on Tomorrowland where the Fireworks Explosion and rocket flyby happens. The deep bass of the explosion and rocket rumble is missing. Yes there is some bass, but stick the ATV3 there or use Auto on ATV 4, multichannel and you can feel the difference.

Could it be that they are dropping or mis-mapping the .1 (LFE) channel?

That and the continuing random jerkiness of movies streamed directly from iTunes Home Sharing Library. It just randomly becomes jerky even after the movie has already loaded into ATV4.

I have watched quite a few movies and TV shows via Homesharing on my ATV4 and don't have that problem. Could be a networking issue on your end.

 

[Colonel Badger]

Could it be that they are dropping or mis-mapping the .1 (LFE) channel?
I have watched quite a few movies and TV shows via Homesharing on my ATV4 and don't have that problem. Could be a networking issue on your end.

No there's definitely an LFE track. I hear bass from my subwoofer but it's just not as impactful.

 

[Rigby]

No there's definitely an LFE track. I hear bass from my subwoofer but it's just not as impactful.

That doesn't necessarily prove that the LFE channel is handled correctly. It could be your receiver re-routing low-frequency sounds from some of your other speakers (if you configured them as "small" or similar in the receiver's setup).

 

[westrock2000]

I have taken to just doing blanket +6db audio volume increases when ripping a movie. Granted I am using an ATV3, but I have noticed the volume is much lower when watching movies (though still sounds good).

 

[andrewstirling]

Anyone know if the new beta software fixes this?

 

[Snoopy4]

Anyone know if the new beta software fixes this?

It seems all they need to do is pass through the damn signal. I've got to think this Siri interface is the issue. What I want to know is how or why did Dolby sign off on this rubbish? Are they not testing product, or has Apple played a bit too much here and done some post certification mods to accommodate sound effect overlay?

 

[5097842]

I use Apple everything, and have had each AppleTV since they were released. But this issue with ATV4 sound is a deal breaker. While the UI is horrible on my 2015 Android TV, the audio is full range and the apps have consistent volume. I (for now) rent movies from Google Play and Vudu thru the TV, both of which have comparable picture quality but superior sound.

I am eager to get back to my AT4, so Apple please fix these problems. PS - I know this is not an Apple problem, but having Amazon Video and Vudu is nice too.

 

[john.burn]

Anyone know if the new beta software fixes this?

The menu item (surround sound) now gives three options -

Best Quality Available
Dolby Digital 5.1
Stereo

John.

 

[andrewstirling]

No improvement though with the new release.

 

[kagharaht]

The menu item (surround sound) now gives three options -

Best Quality Available
Dolby Digital 5.1
Stereo

John.

They change the wording. That's all. What a joke! lol