First 24/96 Experiences With iTunes

Hey I'm really noob at computer audio.

I realized that my Conexant SmartAudio HD thingy that my laptop came with can have the option to play back at 24/192 settings. Does that even work?

I've recorded a few tunes at 24/96 from vinyl and sent these to iTunes as .wav files. In experiments with playback of vinyl, digital to digital, digital to analog, etc., i.e. analog out of computer to analog in HT, digital out of computer to digital in X-FI HD to analog in HT, and digital out of computer to digital in X-FI to optical in HT, I cannot distinguish sound quality between any of these interfaces from computer to HT. My computer is a DELL Inspiron 14 which has an IDT  HD sound processor. My conclusion is I did not need to spend for anything other than a stereo mini out to RCA stereo connecting cable for really good Hi-Fi stereo sound. Also, I have discovered I cannot distinguish 16/44.1 from 24/96. In fact, I cannot distinguish SACD from some material downloaded to iTunes at 256 no matter how the material gets to my HT, a Sony TA-E9000ES with optical Toslink input which will accept a 24/96 signal for stereo or multi channel output. My system is very high-end and and my ears are O.K. too, so, I wonder whether anything over 16/44 has a benefit?

At any rate, sending any signal from my computer to my X-FI HD and then on to the Sony via optical Toslink will get it there at 24/96. Thing is, like you I, was not sure where the upsampling iwas taking place. I now know it's taking place at "sound properties" within the computer. Now, I wonder though if the up-sampling is effecting sound quality; but, so far, I can't distinguish.

BTW, although I question the need for any external DAC for getting computer audio to HT, the X-FI HD also works as an ADC. This allows me to digitize vinyl which is appealing. Thing is, I have not tried my mini mic input at the computer to compare the results between it and digital coming from he X-FI.

Quote:

Originally Posted by Red Jacket Mike 

I do not hear any difference when playing 16/44.1 material upsampled to 24/96 in the Mac Mini's audio/midi settings.  

 

I have downloaded the Steely Dan/Gaucho album in 24/96 from HD Tracks.  I also have an older copy of the CD, which I've ripped using iTunes.  When playing the downloaded 24/96 version, I do hear a difference over the CD version upsampled to 24/96 from 16/44.1.  I'm not sure if its better, but there is a subtle difference.

 

Most importantly, though, I think I'll just leave audio/midi settings permanently on 24/96 for iTunes to lock on to; then, when I do download/purchase the occasional 24/96 material, I won't have to go in and manually adjust settings.

 

So with my iTunes tracks playing from ripped CDs, the original material on the disc is 16/44.1; iTunes then upsamples it to 24/96, plays it back using the Mac's core audio (which passes it along unchanged); it then goes out the mini/optical jack and over to my DAC Magic, which upsamples it again up to 24/192.  

 

If all that juggling is doing anything negative to the signal, I certainly don't hear it.  Everything sounds great by the time it reaches my headphones.  Still wondering, though, if there's anything I should be doing differently . . .?

I've experimented with the same material as you, the "Gaucho" piece. And, I too have wondered about all this conversion/up-sampling stuff. It has provided me with hours of entertainment as well as distraction. I've slipped on the snake oil a few times so ( pun intended) I'm a little jittery about upgrading right now as I'm not convinced it's even possible, unless I go overboard on new speakers for my HT.

BTW, how do you get 24/96 to iTunes? I've done it, 24/96 .wav files; but, it was tedious, using software from Creative which pains my brain.

On the Mac at least I'm pretty sure the operating system will output at the speed you choose in Audio/Midi. The state of your LED's supports that, and so does the indicator on my receiver.

The best data I have is that when iTunes starts it gets the current speed from the operating system (i.e. what was most recently set in Audio/Midi), and then operates at that speed. So if you start out at 44.1, run iTunes, then switch to 96 in Audio/Midi and play a 96 source, iTunes will convert the 96 source to 44.1, because it thinks that's what the OS wants. The OS will then convert back to 96, because that's the speed you told it to use in Audio/Midi. Such a double conversion is undesirable, to say that least.

To avoid double conversion, if you want to play 96 data, and the DAC you're talking to can handle 96, you should exit iTunes, set the speed to 96 in Audio/Midi, and then restart iTunes.

If you play a mix of 44.1 and 96, you should probably leave the Audio/midi setting at 96. Then when you play 96 material, it will go through unchanged. When you play 44.1 material, iTunes will upsample it to 96, and send it to your DAC at 96. Normally DACs run at a fixed speed internally, and do speed conversion from the source. I believe 96 is the most common native speed. So depending upon what speed you set in Audio/Midi, when you play 44.1 material, the upconversion will either happen in uTunes (if Audio/Midi is set to 96) or in your DAC (if Audio/Midi is set to 44.1). It's certainly possible that the results will be different, because one or the other might do a better job. Supposedly current versions of iTunes do pretty good conversions, but I typically run iTunes at 44.1 and let my DAC do the conversion. because I trust the DAC more than iTunes. That is not necessarily true for all DACs.

I did not mention it; but, I'm using a Dell Inspiron 14 loaded with Windows 7. The internal sound processor is an IDT HD. Starting at the control panel, I see that the Creative Sound Blaster S/PDIF-properties is set at 24/96 for shared mode. While listening to iTunes (files recorded at 16/44.1) my Sony TA-E9000ES indicates, going from iTunes with USB out to X-FI HD, and then, optical out from the X-FI HD to optical in on the Sony, that the signal is received at the Sony at 24/96.

 Using Record Now software, I can convert vinyl to digital at 24/96, although separating tracks with software is tedious. Finished recordings can be automatically placed in my iTunes library at 24/96 .wav. At any rate, I'm a newbie with digital and computers in general  but find it all to be very interesting.

For the most part, it sounds to me, that were it not for an occasional snap, crackle, or  pop, I am unable to distinguish, CD, SACD, and ACC from vinyl.

Oh, where do you all think the up or down sampling is taking place? BTW, I have no way of adjusting any iTunes properties except regarding the import of CD's, which only allows for up to 16/44.1. These files appear at the Sony to be up-sampled to 24/96 unless I go to S/PDIF-properties and switch from 24/96 to 16/44.

I do my audio on Mac OS, so I'm not the one to ask about details of processing on Windows. Apparently things have gotten a lot better on windows in the last couple of versions. 

Unfortunately changes can occur at lots of different places: iTunes, when the OS gets it from iTunes, and when the OS sends it out. Furthermore, a lot of people use other audio processing tools. Indeed it used to be that you had to to bypass the lousy internal Windows processing, but that shouldn't be true for Windows 7. Each different piece of software can do something to the sound.

Here's Benchmark's instructions for Windows 7: http://www.benchmarkmedia.com/wiki/index.php/Windows_7_Audio_Playback_-_Setup_Guide

They make excellent external Digital to Analog Converters. They've done a lot of testing of both Mac and Windows to see how best to get sound out to their DAC. It should work for any external Digital device. 

Here's the more general background article: http://www.benchmarkmedia.com/wiki/index.php/Computer_Audio_Playback_-_Setup_Guide

They used to have an interesting article showing actual waveforms with various setups. Some of it was pretty horrifying. I can't find it at the moment, but maybe you can.

I took your advice and went to the Benchmark site. The manual says Windows 7 is performing up sampling for what ever sound properties is set to. Thank you for the link.

You may want to look at alternatives to iTunes for playback - PureMusic and Amarra provide iTunes integration and on the fly adaption between bit depth etc.

Better still, try AyreWave instead - same auto-adaption, zero cost.

Can't do it, Pure and Amm. are not available for PC.