AppleTV 4 surround sound issue

Alright, all. This discussion is way above my pay grade and well over my head. So for this simple guy who has a pretty nice 5.1 setup, which is the best audio option for watching iTunes movies & TV shows and Netflix for me to select? Dolby digital or Best Audio Available? I just want the audio to sound as good as possible.

The basic "rule of thumb" here is, "If you hear a difference and it makes a difference, then use whichever mode sounds the best to you." As bodosom said, use the Best Quality mode {PCM} if you wish to maximize potential playback quality and guarantee maximum compatibility with multichannel formats greater than 6 channels and/or source audio formats having bandwidths greater than 640Kbps. However, it will not improve the quality of your source audio so don't expect miracles here. In fact, moderate quality PCM audio output may sometimes seem "duller" than your Dolby Digital 5.1 output since it does not "colorize" the audio in the way that Dolby decoder algorithms tend to do. On the other hand, you are always free to make whatever adjustments to settings and/or employ whatever AVR feature options you feel best enhance your listening enjoyment which is, for most of us, somewhat subjective.

I wouldn’t hold your breath, It’s actually been over 2 years since the lack of pass through, on the Apple TV4 and now the Apple TV4K, was mentioned and still nothing. I, and many others, have submitted feedback requests to Apple on this and again still nothing.

I think I'll up my AC3 passthrough requests to one-a-week and add a second weekly enhancement request for tvOS to also support AAC surround sound if they want to "decode" everything sent to the tv device.

It sounds like this issue has been fixed in the latest iOS 11 / tvOS update. At least to my untrained ears.

anyone else hear a marked improvement? I did a side by side with my trustworthy Apple TV3 and thought the sounds were very similar where before the ATV3‘s sound was much better than the ATV4.

Michael

I know this is a year later but no it is not set to global reduce dynamic range and the Apple TV for still has this issue Apple has completely ignore users on this has never been fixed I hope that with the new Apple TV 4K this issue will be fixed but I’m not holding my breath I don’t know why Apple doesn’t just give you an AC three pass-through mode

I wouldn’t hold your breath, It’s actually been over 2 years since the lack of pass through, on the Apple TV4 and now the Apple TV4K, was mentioned and still nothing. I, and many others, have submitted feedback requests to Apple on this and again still nothing. This is why, IMO, the device has no business being attached to my high end avr, which I purchased to handle the audio. I, personally, do not want a $200 hockey puck performing this function.

Yes same problem exactly with mine. I tried it using HDMI to TV then optical from TV to Surround system. I could get sound but as you say, only in Stereo, and was unable to get DTS in any way.

I returned mine and won't buy another until they restore the optical out.

1. Are you feeding HDMI to your TV and then taking optical from your TV to your amp? If so then some TVs don't support DD and/or DTS passthrough from HDMI to optical, and others require that you enable it in a configuration menu.

2. You may need to alter the audio output settings in Apple TV 4. I think they are not helpfully labelled. My Apple TV 4 was playing Netflix content in PCM multichannel (i.e. decoding the Dolby Digital audio to multichannel PCM) by default, and only when I changed the audio setting did I get a Dolby Digital bitstream to my Amp over HDMI instead. It may be your Apple TV is defaulting to PCM 2.0 output rather than bitstreaming because it doesn't think your TV can handle multichannel PCM (or Dolby?)

Just a couple of thoughts.

Hi Steve,

What setting did you change in the Apple TV to get Dolby Digital?

I tried all of the options on mine and could get sound but it was always PCM out of the TV.

Tried the options within the TV itself and still no joy.

I've not had the chance to investigate this (mine hasn't arrive yet) but it's been reported that while setting the Surround sound option to 'Auto' produces a PCM output, setting it to 'Dolby Surround' produces Dolby Digital when the source material provides it.

Settings->Audio and Video->Surround Sound->Dolby Surround (sic)

My receiver indicates it is being fed 7.1 PCM when in Auto mode and playing Daredevil in Netflix - and the rear speakers in my 5.0 set-up are definitely getting surround content.

My receiver indicates it is being fed 5.1 Dolby Digital when in Dolby Surround mode and playing the same content in Netflix, and again I'm getting rear surround content.

Thanks Roger and Steve,

I did try setting it to Dolby Surround in the ATV4 but then there was no sound at all via Optical Cable from TV to the Audio receiver. When I set auto I got PCM to receiver.

It may just be that you are mixing up your nomenclature, but Dolby Digital and DTS are different things.

Have you checked for any audio passthrough settings in your TV?

HDMI audio passthrough to Toslink is a hit-and-miss affair with TVs. Some TVs will only accept PCM 2.0 audio over HDMI, and only output Dolby Digital audio when it is received on broadcast received by their internal tuners.

Some will accept DD and PCM 2.0 via HDMI and output this via Toslink. (Some may even accept DTS)

If your TV doesn't offer a solution then you could investigate something like this : http://www.amazon.co.uk/ZILONG-Extractor-Converter-TosLink-Version/dp/B010LRHNTW /ref=sr_1_1?ie=UTF8&qid=1446381753&sr=8-…

Some HDMI Audio extractors only extract PCM 2.0 - others will modify EDID to indicate Dolby Digital support to sources and allow for DD audio to be extracted to Toslink.

You may need to alter the audio output settings in Apple TV 4. I think they are not helpfully labelled. My Apple TV 4 was playing Netflix content in PCM multichannel (i.e. decoding the Dolby Digital audio to multichannel PCM) by default, and only when I changed the audio setting did I get a Dolby Digital bitstream to my Amp over HDMI instead. It may be your Apple TV is defaulting to PCM 2.0 output rather than bitstreaming because it doesn't think your TV can handle multichannel PCM (or Dolby?)

On my system, the global "Surround Sound" setting determines the audio format output by the unit irregardless of the audio format encoded in the source file. In the "Auto" mode, the TV4 outputs audio in PCM with the source track mapped to 7.1 channelization—i.e., my enabled DD ProLogic 2 AAC stereo track is output as PCM stereo mapped to 7.1 stereo channelization and my secondary disabled DD5.1 AC3 surround audio track is output as PCM surround audio mapped to 6 of the 7.1 channels as programmed. On the other hand, if the global "Surround Sound" switch is set to "Dolby Surround," then my primary AAC audio track is output as stereo AC3 mapped to DD5.1 channelization and my secondary DD5.1 track is mapped to all 6 channels. Lastly, the global "Surround Sound > Stereo" setting outputs both my stereo AAC and AC3 DD5.1 audio tracks as Stereo PCM. In all cases, applicable receiver "Effects" settings worked normally. As a final test, I sourced some HiRes (24-bit 192.0 KHz) WAV stereo PCM audio files through the same TV4 global "Surround Sound" settings with the same results—i.e., the global setting determining the output compression format and source channelization determined the maximum possible number of channels mapped to the surround output format. However, it is still unclear if source PCM and AC3 source content is "passed through" natively or if all audio is "converted on the fly" by the TV4 to the user's targeted global "Surround Sound" setting and if so, what sampling settings are used.

These pictures might help.

With Optical Cable from ATV3 to Sherwood receiver I get Dolby Digital with most movies - surround sound is perfect.

With ATV4 and using Optical Cable from TV to receiver, I only get 'DSP" The sound is clearly softer / flatter and very little surround.

If I set Dolby Digital to ON with the ATV 4, no sound comes out of the TV's optical output.

If I set it to Auto or Off I get the "DSP" from the TV optical output.