Apple Reportedly Developing High-Definition Audio Format with 'Adaptive Streaming'

[.Locke]

Totally agree. What software did you use for ABX? What material? Did the ABX software generate the second version of the file and if not, what was used?

There was no PC involved...
We connected two Denon 3910 to a Pioneer vsx-ax5ai via iLink (firewire). Our amp was a Marantz SM-11S1 (Pioneer was used as a pre/pro) and the speakers were a pair of Pioneer S-1EX-W.

We had 2 copies of every disc. The 1st player was reading the stereo track of the SACD (or the DVD-Audio when available) and the 2nd player was reading the CD layer of the SACD disc (we used hybrid SACD). Note that when we were listening to a DVD-Audio we used the 24bit/192khz version of the recording.

One person was blindfolded at the listening position and the other was controlling the equipment. The person at the listening position was auditioning first the SACD / DVD-Audio, then the CD layer and afterwards a random choice of the two. He had to identify if the random choice playing was a CD or a SACD / DVD-Audio.

We tried 50 times each and the vast majority of the answers (I don't remember the exact number) were correct.
After that we rested for an hour and tried an easier for the brain AB test. We were listening (blindfolded) to the
SACD / DVD-Audio and the CD, until we could identify which was which. We could pick out the high-res source every time...

 

[KnightWRX]

Xiph.org posted a lengthy article about why 24/192 would be a big industry hype campaign with little substance, following these Neil Young and Apple stories :

http://people.xiph.org/~xiphmont/demo/neil-young.html

These are the guys behind FLAC and Ogg Vorbis. Interesting read. Especially interesting since they've also been in contact with Neil Young's people about this subject.

So really, it's not about bringing us lossless audio, it's about bringing us compressed audio with "higher resolution", which is basically just a bunch of extra wasted space on our hard drives. A good way to obsolete our current storage technology and make us buy new stuff with little to show for it.

I'm again saying what I've been saying all along : Just give us damn FLAC or ALAC.

 

[milo]

The 1st player was reading the stereo track of the SACD (or the DVD-Audio when available) and the 2nd player was reading the CD layer of the SACD disc (we used hybrid SACD).

Do you know for a fact that both of those versions were identical mixes, just at different sample and bitrates? If they're not and they did special mixes for the higher resolution, your test is meaningless.

Probably easiest to do a test like this using a computer, start with the higher resolution files and convert a 44/16 version using the best software you have available. Plus then you can use real ABX software.

 

[.Locke]

Do you know for a fact that both of those versions were identical mixes, just at different sample and bitrates? If they're not and they did special mixes for the higher resolution, your test is meaningless.

Probably easiest to do a test like this using a computer, start with the higher resolution files and convert a 44/16 version using the best software you have available. Plus then you can use real ABX software.

In most cases we used 2 identical SACD and 2 identical Universal players. One player was reading the SACD layer, the other player was reading the CD layer. In a few cases we used 1 DVD-Audio and 1 SACD of the same program and mix. (The studio had released the program in both formats)
Yes I agree, the easiest way is using a computer, but we wanted to make a test using only high quality audio equipment, without the use of a computer.

 

[milo]

Again, how did you confirm it was an identical mix, and not remixed for the higher resolution format?

And "using high quality audio equipment" is certainly possible with a computer, just use digital outputs.

 

[chirpie]

Again, how did you confirm it was an identical mix, and not remixed for the higher resolution format?

And "using high quality audio equipment" is certainly possible with a computer, just use digital outputs.

I have to agree. All it takes is for one master to be mixed 1db louder and it screws everything up. Even the different components could introduce a difference that large if one isn't careful.

I'd do a blind listening test by starting with a 24/96 recording and then just make my own down samples using something like soundbooth, logic platinum or even soundtrack pro.

Play it all off a back to back list from a computer.

Plus it makes the differences easier to spot as the typical aural memory is completely lousy.

My own two cents anyway.

 

[.Locke]

Again, how did you confirm it was an identical mix, and not remixed for the higher resolution format?

And "using high quality audio equipment" is certainly possible with a computer, just use digital outputs.

In the SACD that we used the studio had either made an original DSD recording or used the original master tapes to create a dsd master. For the CD layer of the SACD they downsampled / reencoded the DSD to PCM 16bit/44,1khz.

 

[pika2000]

Totally agree. What software did you use for ABX? What material? Did the ABX software generate the second version of the file and if not, what was used?

The easiest one to use is foobar2000. I use it all the time to ABX different codecs/bitrates. Doing ABX blinded test on hardware is doable, but not easy (which makes me think anybody that claim to have done it is lying if they cannot show their result).

 

[.Locke]

The easiest one to use is foobar2000. I use it all the time to ABX different codecs/bitrates. Doing ABX blinded test on hardware is doable, but not easy (which makes me think anybody that claim to have done it is lying if they cannot show their result).

Any result could easily be fake. Reading some 'results' is by no means a way to tell if someone is lying or not. The only way to be absolutely sure that someone is telling you the truth about an audio test is to be there when it is performed.

The difficult part on a hardware test is to own (or find someone to loan you - very difficult) the right equipment.
I was lucky that a friend of mine had the speakers and the amp mentioned above and I was very lucky to have an AVR that could connect using firewire to both players. Other wise we could never be sure if what we were hearing was the result of a different cable connection (digital vs analogue),different dacs (internal dacs of the player vs the dacs from the AVR) or the differences of the program itself!
So all I had to do was to drive at my friends place with my player and my AVR. Some may say a lot of work is required for such a test, but I see it as fun.

Even a PC with digital outputs or an external dac will not be as good as a dedicated system for music (or movies). One of the reasons we did a hardware comparison is that the hardware we own has a much better quality than our computers.

It is very easy for anyone to make an ABX test on any computer. The problem is that most computers cannot even come close to a dedicated hardware setup that costs thousands of euros...

 

[milo]

Even a PC with digital outputs or an external dac will not be as good as a dedicated system for music (or movies). One of the reasons we did a hardware comparison is that the hardware we own has a much better quality than our computers.

How is the digital output from a PC any worse (much less different) than the digital output of any other piece of gear, regardless of price? Sounds like you don't understand how digital audio works.

 

[.Locke]

How is the digital output from a PC any worse (much less different) than the digital output of any other piece of gear, regardless of price? Sounds like you don't understand how digital audio works.

Maybe you will change your mind if you hear a CD playing from the toslink of my panasonic BDT310 and then the same CD playing from the firewire of my denon 3910. (SPL matched of cource and both decoded at the AVR for a proper comparison)

Digital audio works quite differently than most people think. For some reason many believe that a digital connection is of the same quality regardless of the device and protocol... that is not the case. Try googling for jitter and how it effects a digital transmission.

Mac's optical out is of great quality but still, if you want something better you have to buy a good dedicated Universal Player. Of course you need good speakers, good amps, a good pre/pro and good mastering/mixing of the disc to unlock the potentials of such a player.

A computer is not of any help in my case. A multichannel DVD-audio or SACD cannot be transmitted through SPDIF (either toslink or coaxial). Not to mention that a computer is a very noisy environment (from an electrical point of view).
Of course for 256kbps AAC or ALAC files I'm very happy with my iTunes. I use them only for syncing with my iPod touch though (or a party, where changing disc is annoying). For critical listening I prefer my dedicated player...

 

[ph0enix2012]

Because I'd like the highest quality sound for plugging iPods/iPhones into my high-end home system, and even my high-ish end car system when I can't be bothered changing CDs.

CDs are recorded using just two channels (stereo). I can only imagine that by High Definition Audio, Apple actually means more channels than that. I was really disappointed when the DVD-A format died. I had some sample music recorded in 5.1 and the sound quality was simply amazing when played on my DVD-A capable player. I'm hoping that Apple's HDA will be similar to DVD-A but better.