Alpine CDA-9887 Apple Lossless vs CD
 

Howdy,

I have an Alpine CDA-9887 with an iPod connected via "Full Speed" USB.

According to a rep at Alpine, the iPod sends a digital signal over USB to the deck, and then the deck's 24bit Burr-Brown DACs D/A it.

According to Apple, Apple Lossless, which is part of the MP4 AAC-LC spec, should be identical to the digital source.

So here's the weird thing.

When I A/B the same song from a retail CD and the Lossless file that was ripped from that very CD, there is a noticeable difference. I've had other people listen and they agree. The CD sounds cleaner and more defined.

So, my question is this. (Bracing for guesses and conjecture and opinions)

Is there a difference because:

1- Apple Lossless isn't really lossless.
2- The iPod decodes all audio into PCM, badly, and sends that.
3- Someone is lying and the iPod's crappy DAC is doing the D/A and sending analogue.
4- I'm hearing things

Thanks!

-Drunkenrobot

here is a good read for you ;)


http://www.audiokarma.org/forums/sho...d.php?t=137477

So, there is a possibility that the ECC ripper in iTunes introduced artifacts into the Lossless file... I will re-rip the CD with EAC and transcode it to Apple Lossless and have another listen. Maybe that's the issue. Thanks!

...and unless you do a proper abx test with the two, you can't be sure you're actually hearing a difference, or if it's psychoacoustics playing tricks...same old story. Anyway, if you feel one sounds better, then by all means use what you like better...if your mind tells you one sounds better, who cares what anyone else says!

Yeah. That's why I was wondering if I was hearing things! :-)

I wish it wasn't so hard to do a double blind.

I also wish I could find out if the iPod was sending PCM or straight encoded data.

Is the deck decoding the audio to PCM for the DAC or is the iPod decoding PCM for the DAC?

Did you do apple lossless without correction?

I ripped a brand new, just out of the wrapper CD with iTunes, with ECC (error correction) turned on, and encoded it into Apple Lossless.

I REALIZED YOU HAVE A 9887 WITH A 422i CABLE..THAT SYSTEM WAS ANALOG AS FAR AS I RECALL, IT OFFERED HIGH SPEED FILE SEARCH AND DOWNLOAD, BUT THE OUTPUT WAS ANALOG. THE NEW DECKS USING THE 440i CABLE LIKE THE CDA 117 ARE PURE DIGITAL, SO THE DIFFERENCE YOU HEAR IS PROBABLY CORRECT.
check this thread out for more info specific to the high speed cable:

http://www.diymobileaudio.com/forum/member-reviews-product-comparisons/30884-alpine-cda-9887-full-speed-connection-analog-digital.html

Hmm. Good point. It may be just a level thing. The cd is certainly much much louder, and I have to turn the sub down quite a bit, relatively. I'll try ripping the test track again with EAC and re-encode it and see how it comes out.

I also wonder if the deck or the iPod does the decoding to PCM. The deck may be using the Burr-Brown to do the D/A, but which one is doing the decoding to PCM?

I changed my reply if you missed it above...the 9887's ipod out is analog meaning the ipod does the dac'ing..the signals through the 422 cable are analog. check back my reply it has a link to a thread that discussed this in more detail. Sorry for some reason I thought you had a cda 117 which is pure digital.

Hmm. Sounds like nobody know really still.

Alpine told me it's all digital all the way.

That site you mentioned is still in both camps. (Both sides insisting that they are right).

Hmm, whatever.

I'm pretty sure it's analog as I checked back all the brochures from when the 9887 came out and none mentioned the pure digital stream unlike the products that now have it. That's usually the best way to know, as it would have been a big deal at the time when the 9887 came out. Until a few years nobody had direct access to the ipods digital stream, even in home audio it wasn't until the Wadia itransort dock came out. Right after that many more head units came out with direct digital usb hook up. The first Alpines with it were the x series ipod controllers around 2008/9. The big deal was the 24 bit burr brown dacs and imprint when the 9887 came out.

Do you have any of the eq settings on on the iPod?

I'm pretty sure the eq settings will affect sq only if it's an analog output, as it's processed in the analog domain. With a pure digital out, only the oriinal digital stream is outputted..I guess that's an easy way to check if it's analog or digital. If someone with a cda 117 or 105 can check this it would great, and an easy way to know if you have a digital output. Unfortunately, I have an analog output and I know the eq affects the sound as I've tried it a number of times.

The EQ settings only affect the headphone out, not the line.

I was holding out for proof that it was an analog connection. Nobody seemed to have proof, only opinion.

So I decided to test it myself. I disconnected the left analog pin on the iPod 30 pin cable, and the left channel went dead. I reconnected it and sound came back. So, all evidence points it to being analog. What a waste of 24bit Burr-Brown DACs, I only get to use them with the CD player, nothing else.

I think the thing that is missing in mp3, mp4 etc vs. CD's it that CD's have more dynamic range (at least the newer releases in the CD "era") then any compressed or non compressed format. I think a copy of media can have the same sound quality but lack the dynamic range (or punch as some would say) that the original does
If you have a high quality system, the differences would be more pronounced then a cheap one.
that is why if I want the best sound, I am staying old school and sticking to CD format, even if they are harder to find.

cheers

randy

I think most of us are forgetting that the cd comes from the data on a computer to start with. After the tracks are all mastered, they are burned to a cdr or stored on a drive and sent to the cd manufacturer...it is this info that creates the glass master, father and mother pressing discs that make the cds that we buy. So, to assume that a file of the exact information that is on the cd is not as good as the plastic disc makes no sense..it all originated from a stored file on a computer. If the file is corrupt in some way, then certainly that will affect quality, but if it's bit accurate lossless, then it's the same information.

Actually my set up with a 9833 and 420i ipod interface is analog, but I can still use the eq in the ipod (through preouts/dock connector). I guess after Alpine went to high speed the eq function no longer functions (9887). According to the techs at Wadia (makes of the 170i ipod digital interface), the eq will function with digital out as it's part of the dsp. I have not tried it yet...my next system will have the ipod digital input (just waiting to see the next Alpine line up in the spring).

true

but when you compress music SOMETHING has to go... even when you use lossless compression there still is a trade off somewhere as with the old saying "can't get something from nothing"
so I could be totally wrong, but this is why I believe CD still can sound better then mp3, mp4 etc

cheers

randy

lossless means lossless...just like a zip file unzips to give you all the info to run your program..so does lossless. This seems to be a hard concept for everyone to grasp. Just google it. Something does not have to go, not if you know what the missing parts are, and can fill them in when expanded. That's what the compression codec does. example: all CAA cards in south central ontario start with 620 282 xxxxxxxxxx, if I wanted to store a million card numbers in a file and reduce the space it takes up, but still have all the information when expanded. I can just add the xxx numbers, and when expanded, the program will just add 620 282 in front of all of them. That's how a lossless codec works. That's why it can pass a bit checker for accuracy and be mathematically identical to the original (obviously it's much more complicated than that, but that's the general idea).

thanks very much for the info. so what can explain the difference in sq that some people are claiming? (my equipment is pre mp3) I do know when I plug in the kids ipod into our receiver at home it lacks the punch of the original cd.

thanks again

randy

well lots of things...what is their mp3's origin, did they get it after it was recorded of the radio and then digitized..very common, or recorded using analog means. where did it come from...my space, you tube, napster, etc...many of those mp3s are impossible to know the source. I can tell you that a properly ripped mp3, aac, etc.. at a reasonable bit rate, say 128 kbps and above, is very good, and all but a few with really transparent equipment would have a tough time telling the origianl from the mp3. Another factor is the ipod levels. I've found that ipod output levels are significantly lower than the cd's level in my deck and most others as well. This causes you to think that the louder one is better quality (common psychoacoustic effect which is probably the number 1 reason most people can tell th difference between 2 sources...when the sources are level matched..it becomes much harder). Yet another factor is just plain prejudice, we all have been influenced over the years by all the audiophile claims that this can't sound as good as that, and that you need 1000.00 cables to have great sound, and mass produced electronics can't sound as good as 10,000.00 esoteric audio components, etc...The idea that a pocket sized device tht can hold thousands of tracks can actually sound good is blasphemy!