shenzi Posted February 8, 2009 Share Posted February 8, 2009 There's a new series of articles on this starting on UK tech news site The Register. They're fairly robust about these things (and usually platform agnostic), so it should be interesting. First part is at http://www.reghardware.co.uk/2009/02/06/apple_tv_hacking_part_1/ Link to comment
The Computer Audiophile Posted February 20, 2009 Share Posted February 20, 2009 Hi Jeff - I finally got around to doing this experiment for you. Everything I played off the local AppleTV hard drive came out at 44.1. I tried 88.2 and 96k tracks without any bit perfect luck. They were all downsampled to 44.1. Native 44.1 works bit perfect every time. Founder of Audiophile Style | My Audio Systems Link to comment
HarryHWombat Posted February 25, 2009 Share Posted February 25, 2009 Is there any way to tell if this is 44/16 or 44/24? Link to comment
The Computer Audiophile Posted February 25, 2009 Share Posted February 25, 2009 Wow, the one test I didn't conduct! this one may be a little tougher because I'll have to find some 24/44.1 content that is HDCD just to see if it will pass 24 bit content. Hmm, let me work on this one. Founder of Audiophile Style | My Audio Systems Link to comment
HarryHWombat Posted February 25, 2009 Share Posted February 25, 2009 Chris -- I read somewhere, possibly on a manufacturers forum, that bit-perfect output from OS X is only achieved (for 44.1 music) through 44/24. This is a little strange and I can't figure out why. It would be interesting to see what 44/16 music was output at - Audio Midi defaults to 44/24 which suggests that this is Apple's preferred output. No need to hunt around for 44/24 music - just see what 44/16 outputs as. [EDIT: The above information has the status "I read it somewhere" so may in fact be completely false. On the same forum some ears have preferred 44/16 output and some 44/24 - ah hi-fi ] Link to comment
The Computer Audiophile Posted February 26, 2009 Share Posted February 26, 2009 "I read somewhere, possibly on a manufacturers forum, that bit-perfect output from OS X is only achieved (for 44.1 music) through 44/24" I hope you read this one in your dreams :~) It's misinformation. I can output a bit perfect signal at 16/44.1. Founder of Audiophile Style | My Audio Systems Link to comment
bottlerocket Posted March 1, 2009 Share Posted March 1, 2009 I am also interested if the ATV can output hi-res files. Also is it possible to get hi-res audio (96/24) into Itunes if using Itunes on Windows/XP? Itunes Windows/XP >>> ATV >>> Cambridge Audio DACMagic >>> NAD 712 >>> ADS L7 Link to comment
Ashley James Posted March 1, 2009 Share Posted March 1, 2009 I think all Apple streams are SRC'd to 16/44, probably to avoid wireless issues. I've got some 24/172 files that I play on mine at 16/44 and you can't here the difference, so I wouldn't worry. We've got much more revealing kit than normal passive speakers and we're done a lot of comparisons by changing the sample rate of our DACs whilst playing music and you don't hear any difference between 16 and 24 bit, which is what is predicted. The big advantage of 24 Bit is at the production and recording stage. We get loads of emails from people who've found 24 Bit recordings that sound better than 16 Bit ones, but who haven't realised that the difference is the relative quality of the recordings themselves and not the number of bits. Some sound worse too. Recording quality is what matters most. Ash Link to comment
bottlerocket Posted March 1, 2009 Share Posted March 1, 2009 Ash, are you saying if you have a 24/96 his res music file and play it back at 16/44, it will sound pretty much the same as playback at 24/96? Or are you a 16/44 file is indistinguishable from a 24/96? Link to comment
Ashley James Posted March 1, 2009 Share Posted March 1, 2009 I am really and it's not as daft as you might imagine. If you Google this one, you'll find quite a lot of experts saying this too. The reason is that an awful lot of CDs only use about 20 dB of the available 96 dB and Classical Music 45 dB, so the 120 dB of 24 Bit doesn't help. However during the process of recording, mixing and producing music, bits get used up, so if you start with more you end with more and that might make for audible difference. I think people are expecting more from 24 Bit that it'll deliver, far better to concentrate on building a system that makes all music sound better and by that I mean even historical recordings. I have a nearly one hundred year old recording that has been restored and turned into an MP3 and it's fanatastic. Email me at work and I'll send it to you. Ash Link to comment
Tog Posted March 2, 2009 Share Posted March 2, 2009 ash hits the nail on the head - this brave new world of CA brings into stark relief the truism that the original recording quality of the source has the single biggest impact on sound quality. You can throw all the complex reclocking dejitterizing updownaround sampling kit you like at the process but a great deal of it will ultimately be wasted effort. yours, beautifully engineered tog Link to comment
silverarrows Posted March 11, 2009 Share Posted March 11, 2009 I might have missed this but is it that the USB on the ATV not the same as the USB on another computer? That is, it can't be used to connect to a USB dac that does not require any drivers? if I want more than 16/44.1. For me the Mac Mini is too much for a media centre so maybe a good solution for me would the ATV. I have to say, for the money, a PS3 looks like a very good all round option as well. Link to comment
The Computer Audiophile Posted March 11, 2009 Share Posted March 11, 2009 The USB port will not output audio unfortunately. Founder of Audiophile Style | My Audio Systems Link to comment
nwjg Posted March 27, 2009 Share Posted March 27, 2009 I've got a question Chris, I don't know if you will want to guess at an answer... In the home system I am using a Meridian G68 as the DAC. I can go optical from Macbook, or Airport direct to the G68 or would I be better off going ATV's HDMI to take advantage of my new HD621's HDMI ability to up-sample before sending the signal to the G68? http://www.meridian-audio.com/media/105736/hd621-ds2.pdf Link to comment
The Computer Audiophile Posted March 27, 2009 Share Posted March 27, 2009 Hi nwjg - My opinion which is based on no specific research into your question is to use optical on this one. I'm not a fan of HDMI if you only need audio. If you like the upsampling of the HD621 it just might be the right move for you however. Founder of Audiophile Style | My Audio Systems Link to comment
nwjg Posted March 27, 2009 Share Posted March 27, 2009 Thanks for you opinions Chris, and for the site, great reading. Just wondering, why don't you like HDMI for Audio alone? Link to comment
dsbourque Posted April 1, 2009 Share Posted April 1, 2009 Might it be possible to use an HDMI splitter to extract a 96/24 stream from an Apple TV? Link to comment
DavidL Posted April 10, 2009 Share Posted April 10, 2009 A very informative thread. Apple seem to have no interest in upgrading the audio capability to hi-res. I don't buy the bandwidth limitation story mentioned in this thread as 802.11 wireless happily manages the higher data rates required for video; more likely is a desire by Apple not to upset commercial DVD content providers by allowing 24/96 audio to be streamed 'in the clear'. Are there any wireless alternatives, given that it is the whole Apple system for Airtunes that is limited i.e. can iTunes be played, transmitted and received at the source resolution? I store and playback 24/96 direct from iTunes in my Mac Pro. A quick search turned up the Netgear Digital Entertainer Elite EVA9150, but it is not clear whether this can handle 24/96 and there are several posts here from folk who've had problems with Netgear wireless transmission. I'm still a fan of Apple TV for CD-level playback, however I'd pass on my experience that the audio sound quality improved considerably when I moved the ATV from immediately adjacent to my DAC (Bel Canto DAC 3) to 1m away by using a longer length of optical cable. I guess the noise from the hard disk, power supply etc was the culprit; so I'd like to avoid a solution for playing hi-res music that requires a local computer. David ALAC iTunes library on Synology DS412+ running MinimServer with Samsung Galaxy Tab S2 tablet running BubbleUPnP for control > Hi-Fi 1: Airport Extreme bridge > Netgear switch > TP-Link optical isolation > dCS Network Bridge AND PS Audio PerfectWave Transport > PS Audio DirectStream DAC with Bridge Mk.II > Primare A60 > Harbeth SHL5plus Anniversary Edition . Hi-Fi 2: Sonore Rendu > Chord Hugo DAC/preamp > LFD integrated > Harbeth P3ESRs and > Sennheiser HD800 Link to comment
machinehead Posted April 10, 2009 Share Posted April 10, 2009 Hi David, One option would be to use a Macbook or Mac Mini to your DAC via optical, then stream your music wirelessly from a NAS or your Mac Pro. Depending on the size of your library you could get larger hard drive for either machine, I think 500 GB is the limit right now for laptop sized drives, for that matter I believe other forums have documented stuffing a 500GB drive in an ATV. I am with you that wireless can no doubt handle higher res data, as I stream HD content from iTunes from my airport extreme N router. Chris tested for us that 16/44.1 was the max output from the optical port of the ATV, so the ATV is the limiting factor. It would be interesting to hear from others that have tested the sound difference from an ATV optical into a DAC, vs a Macbook or Pro, or a Mac Mini optical into the same DAC. I have a feeling that the sound from the Macbook or Mini might be better. What do yall think? Jeff \"It would be a mistake to demonize any particular philosophy. To do so forces people into entrenched positions and encourages the adoption of unhelpful defensive reactions, thus missing the opportunity for constructive dialog\"[br] - Martin Colloms - stereophile.com Link to comment
nwjg Posted April 14, 2009 Share Posted April 14, 2009 Ok, so I tried to hook up my Macbook pro to my Meridian pre-pro. I know this is probably a noob question but how do I get the Mac to recognize the Meridian? When I plug the Toslink into the mac & G68 and play a song the computer's internal speakers play and the G68 does not. When I open up the MIDI there is only the built-in output to choose from. I use a Mini-dac at the office and it was plug and play. Are there drivers I need to download? Am I just missing something obvious? Thanks. Link to comment
The Computer Audiophile Posted April 14, 2009 Share Posted April 14, 2009 Hi nwjg - This is puzzling. It really should be simple. When you select the built-in output under the Properties For" selection does it say Internal Speakers? Founder of Audiophile Style | My Audio Systems Link to comment
machinehead Posted April 14, 2009 Share Posted April 14, 2009 If you hook the TOSLINK cable to the headpone jack out, does the other end of the TOSLINK, glow red? \"It would be a mistake to demonize any particular philosophy. To do so forces people into entrenched positions and encourages the adoption of unhelpful defensive reactions, thus missing the opportunity for constructive dialog\"[br] - Martin Colloms - stereophile.com Link to comment
nwjg Posted April 15, 2009 Share Posted April 15, 2009 Chris, yes, it says built in speakers machinehead, no, there is no glow Link to comment
nwjg Posted April 15, 2009 Share Posted April 15, 2009 sorry, tried to insert a snapshot but my html is weak Link to comment
nwjg Posted April 20, 2009 Share Posted April 20, 2009 Thanks for the help (especially the glow suggestion). Turns out I had a bad cable. Works like a charm now. Link to comment
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