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ATV (Apple TV) - Bit perfect? AC3? DTS 5.1?

11K views 14 replies 9 participants last post by  Cheezmo 
#1 ·
I'm thinking of getting a new setup consisting of an Apple TV, Time Capsule and iPone. The questions is though whether the Apple TV can put out Bit-Perfect content (as the Airport Express can via itunes) and if I can playback ripped DVDs with AC3/DTS?


Anyone who has a clue about this?
 
#2 ·

Quote:
Originally Posted by Steiner83 /forum/post/13402707


I'm thinking of getting a new setup consisting of an Apple TV, Time Capsule and iPone. The questions is though whether the Apple TV can put out Bit-Perfect content (as the Airport Express can via itunes) and if I can playback ripped DVDs with AC3/DTS?


Anyone who has a clue about this?

yes - AppleTV puts out bit perfect digital (like AE - in fact the new Airport Express in 802.11n) - also passes DD5.1 ripped via Handbrake or Visual Hub (I haven't tried DTS);


However - in your setup you'll need to include a machine that can run iTunes (Mac or PC) that organizes, holds and most importantly streams the MP4 or music content to the AppleTV (Itunes store rental movies excepted).


Many of us (me included) expect Apple to introduce a product this year that essentially provides this link, not requiring an 'iTunes machine'; but that's conjecture and not all agree....


ken
 
#3 ·
Actually, Ken, the real test for bit-perfect in iTunes is its ability to play an audio DTS 5.1 WAV file:

http://www.sr.se/cgi-bin/mall/index.asp?programid=2445


from within iTunes turn off all processing (uncheck sound check, sound enhancer & crossfade playback) and then the AVR should receive it as DTS. That's how we confirmed it with the optical digital out of an Airport Express several years ago--I think that's what Steiner83 is looking for wrt the aTV. I have Macs at every HDTV so I don't have the ability to check it on an aTV.
 
#4 ·

Quote:
Originally Posted by chefklc /forum/post/13404385


Actually, Ken, the real test for bit-perfect in iTunes is its ability to play an audio DTS 5.1 WAV file:

http://www.sr.se/cgi-bin/mall/index.asp?programid=2445


from within iTunes turn off all processing (uncheck sound check, sound enhancer & crossfade playback) and then the AVR should receive it as DTS. That's how we confirmed it with the optical digital out of an Airport Express several years ago--I think that's what Steiner83 is looking for wrt the aTV. I have Macs at every HDTV so I don't have the ability to check it on an aTV.

yep - I know; That's precisely what I'm confirming for you;


AppleTV plays .wav wrapper of DTS files (AND DD5.1 for that matter) bit perfect and recognized as such by my Meridian G68 processor as a DTS input stream, properly decoded by such to 5.1 surround channels in full bit perfect DTS - I have 2 .wav test files in DTS (and 2 .wav in DD5.1) and I'm listening to one of the DTS files now as I type this, via iTunes streamed to my AppleTV, fed to my Meridian G68 which is displaying it as a DTS input stream (sounds wonderful by the way).


I haven't verified a ripped HB movie to some other (mkv or other) wrapper, but HAVE verified DD5.1 in mp4 wrapper ripped via HB, played through AppleTV.


Regardless of the HB encoding though - AppleTV is definitely bit perfect - and most especially if your definitive definition is passing of DTS via .wav wrapper.


ken
 
#5 ·
This may be true, and I only had an AppleTV version 1.0, but even optical PCM 2 channel stereo did not sound nearly as good as it does out of a mac mini. I have Infinity Kappa's upstairs and Klipsch THX ultra 2 downstairs. The difference was so noticable even my wife said it sounded better. The mac mini sounds 'fuller' and more similar to my H/K and Onkyo CD player where the AppleTV sounded soft and dull for what it is worth.


AppleTV 2.0 may have changed all that, but just my experience.
 
#6 ·
Ok! So if Im getting it right, all the content can be on the time capsule but I have to "decide" from e.g. my MacBook what to play and to where. Will Apple TV be a unit just as the Airport Express in iTunes? Do I have to configure Apple TV at all prior to playing the music, movies?
 
#7 ·

Quote:
Originally Posted by Steiner83 /forum/post/13412132


Ok! So if Im getting it right, all the content can be on the time capsule but I have to "decide" from e.g. my MacBook what to play and to where. Will Apple TV be a unit just as the Airport Express in iTunes? Do I have to configure Apple TV at all prior to playing the music, movies?

All the content can be on Time Capsule - Yes;

Have to choose what to play from your MacBook - No:

You use the iTunes running on your MacBook to 'authorize' and stream the music to AppleTV - but with your MacBook running the stream - you select what to play directly from the AppleTV (remote) and it's menu system; This will include any playlists you created in your streaming MacBook iTunes - they will be presented on your TV interface....


regarding the quality experience from doogie - I haven't experienced this. I play DVD-A, SACD, CD, and iTunes stored digital files (the later via AppleTV) through my Meridian DSP all digital system. I can't hear the difference between 'like rez' sources - but Meridian does a lot of buffering to 'fix' jitter and other issues, so maybe that explains some of the difference - not sure...


ken
 
#9 ·

Quote:
Originally Posted by Steiner83 /forum/post/13415479


Does anybody know if iPhone could be used instead of an ordinary laptop/stand alone Mac for creating playlists, organization etc?


Am I able to play content from my iPhone through Apple TV?

No on both counts; but with the new SDK out for iPhone - these kinds of capabilities may well come later this year...


ken
 
#10 ·
No iPhone remote control for iTunes yet. But I think its one of the top three wants now that the SDK beta is out.


I tried Signal but the web interface is too clunky. Prior to that I had a Sony Ericsson phone and Clicker but that was clunky too.


This will really hurt the Sonos business model unlress they adapt. I would buy some of their WiFi amps if I could forego the big remote and use the iPhone or the iTouch instead.
 
#11 ·

Quote:
Originally Posted by SoundKernel /forum/post/13419082


No iPhone remote control for iTunes yet. But I think its one of the top three wants now that the SDK beta is out.

I know this is not what you are looking for, but couldnt someone use remotebuddy and an iPhone to control the mac that is streaming to the aTV?


Not that you would want to. But if they can do that, perhaps remotebuddy can just get the iPhone to control the aTV directly?
 
#13 ·
I've been looking into thi on my own and came across this thread.


M-Audio replied to a product inquiry this way:

Quote:
Unfortunately bit perfect audio is theoretically compromised with

CoreAudio when the volume is altered regardless of which interface you

choose in OSX (with the exception of AC-3/DD/DTS pass-thru). For best

D-A performance, I would recommend keeping the volume turned all of the

way up in iTunes, then connect the optical out via the Transit to the

external converter. While there isn't a way for PCM audio to avoid

being resampled by the CoreAudio kernel, this will provide the least

modified (and therefore bit compromised) signal path.

So it seems you can stream AC3/DD/DTS bit perfect, but not PCM? My personal interest was in streaming Apple Lossless files ripped from my CDs at the best possible quality, but this seems elusive...
 
#14 ·

Quote:
M-Audio replied to a product inquiry this way...

Why are you using a Transit? Which Mac do you have?

Quote:
So it seems you can stream AC3/DD/DTS bit perfect, but not PCM?

In the case of an Intel Mac, aTV or an Airport Express, as long as you're going optical out, and have verified with the DTS wav test that you're getting bit perfect, any Apple lossless files that you play back/stream with iTunes and Airtunes will be received just as cleanly by that next device in your chain, like an AVR, pre-amp, etc. as well.


I wouldn't read too much into that M-Audio response--if the "PCM" you're talking about is redbook CD content ripped as ALAC there's no resampling going on by "the CoreAudio kernel" as long as you haven't messed within AudioMIDI. CoreAudio takes it's marching orders from AudioMIDI, 16/44.1 will stay 16/44.1, ALAC will remain ALAC, and there's no resampling or analog conversion going on as it is streamed to an Airport Express (or aTV) and out its optical port. As long as you're not ALSO playing back higher rez audio content with that instance of iTunes, you shouldn't change anything within AudioMIDI and CoreAudio won't resample any of your iTunes ALAC files.


Now, if you do start experimenting with high rez audio files as well as ALAC, and switch back and forth, that changes things--then you create situations where CoreAudio will resample a file after an app like iTunes has handed it off to it...either up or down, depending, which you might be able to hear...if this is the case, then are some easy rules about how to do it properly, but this doesn't really apply to you since you're concerned with ALAC streaming.

Quote:
My personal interest was in streaming Apple Lossless files ripped from my CDs at the best possible quality, but this seems elusive...

It's not elusive at all. Why don't you be more clear about what you're trying to achieve and what hardware you're using? Many of us here have already been dealing with Apple, iTunes and digital audio for years...


A question, though, as you've been reading and experimenting, are you also backing up any of these suspicions by actually listening to your music? That's important, listen to it all along the way in your various hardware setups, because if you don't, if you're just Googling, reading this link and that link, you risk getting more confused. I guess what I mean is asking questions is good, but don't stay in the theoretical. Make sure you're getting hands dirty, and enjoying your music all along the way, so you can better figure out for yourself what differences you can perceive.
 
#15 ·
I know this is an old thread, but FWIW, the AppleTV(v2) resamples everything to 48khz so will not pass DTS CD data the way the AppleTV(v1) did.


No idea if there is any way to encode multichannel audio that can be played through the new AppleTV (other than AC3 movie soundtracks wrapped in mp4/m4v).
 
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