43 replies to this topic

[audible]

We all know that many alpine head units can control an I-pod. Those tiny white devices you can cram thousands of ripped songs onto and never ever have to insert a disc into your player ever again.

Interesting concept and for most people, a good thing. But not us. Car audio sound quality buffs like us would rather run naked thru the CBD than listen to an ipod thru our car audio systems.
This is what I have thought for years, well since 2005 when Alpine jumped into bed with Apple to create the first high speed head units.
Then one day, I heard about apple lossless compression. A way to have sound quality songs on an ipod and control it via an alpine head unit. Thousands of songs (talking about an hard drive ipod here) all at high SQ, never have to insert a disc ever again?

I had to try. So I bought one to try. Initially I thought to test it being the former SQ judge that I am. I chose a number of my favorite tracks I use for evaluating systems.
These tracks where applied in three formats;

Disc.
Converted to apple lossless ripped from the same discs used for listening.
Converted to "lossy" 192kbps apple what ever they call it.

Then I banged it all into the good olde sigma for a SQ test.
For reference, the head unit is the Alpine DVA-9861. Apple classic 80 gig ipod. Rest of the system is pretty much how it was last time it snaggled a SQ trophy.

The format was easy to switch between. Play the cd then switch to the ipod for easy back to back comparisons.
It was very easy to pick the lossy tracks out, as you'd expect. The real challenge here was the comparison of the lossless tracks to the original discs. Could I tell the difference? Yes. I could.

Overall the apple lossless killed the lossy tracks. Left them for dead. Compared to the original discs there where some slight differences. A slight loss of bass, a slight amount of stridence/sibulence. A slight loss of this and that. No matter what aspect of sq it was, harmonics, sibulance, etc, there was a very slight difference to be heard.
But hearing the difference was quite hard. I had to listen to both the disc and the ipod 2 or 3 times over to confirm what I was hearing. During casual driving/listening, I could not pick the difference when car/road/wind/passenger/etc and other back ground noises where introduced.
Only sitting in my driveway with the engine off and concentrating on listening is the only time I could pick the difference.
In the sigma, that is no mean feat. I also intend to do the same comparison with my home audio set up, but atm I lack the ipod to rca output docking thing. Then we will see what a Denon/B&W set up thinks of the ipod.

Everything I read about lossless compressions indicates that the songs should be identical to the originals in every way. So the difference in SQ I am hearing comes from somewhere else. ipod hardware or connection to the head unit are my number one suspects. I don't know the internal workings of an ipod but I suspect it's a fair way down the ladder compared to the DVA-9861.

Overall however, I am impressed. I'm faced with a slight downgrade in sound quality and in return a huge bonus in convenience. Since my comparison I have managed to cram 2053 songs into the ipod all in lossless. Alpine high speed lives up to its name as I can access the albums and tracks as fast as I can turn the dial.
It is an excellent marriage between the two, one that I'm happy to live with.

I am interested to hear about the technical aspect, to reinforce my ears findings. So feel free to discuss the topic and add your inputs.

Oh, and to anybody who thinks that mp3/apple whatever there equivilant is equals sound quality, you need to buy this

Edited by audible, 04 March 2009 - 05:39 PM.

[Pulse-R]

In deed, apple lossless is the best way to hear 'SQ' from an Alpine/iPod combo.

as for Audiclean ( ) - well, most people can learn the difference in SQ, but few really care.

I think the lack you are talking about exists in the iPods output circuitry. I believe that fullspeed still uses the analog signal from the ipod to the H/U.

There are several "mods" around for iPod to improve the SQ of the analog section (one by Red Wine Audio, for instance).

[shiny_car]

thanks for your findings audible - interesting. whilst i have a basic 8Gb Nano, with tracks recorded via iTunes at 192kbps, i have never tried lossless. of course, my Nano won't hold as many tracks as your iPod!

Pulse-R, on Mar 4 2009, 07:42 PM, said:

I think the lack you are talking about exists in the iPods output circuitry. I believe that fullspeed still uses the analog signal from the ipod to the H/U.

would be even more interesting to try using an iDA model, or CD HU via USB. both these methods would bypass the analogue iPod circuitary, and go straight with digital via USB, relying on the 24-bit DAC in the HU.

cos an iDA has no CD transport, you would need to compare via a CD changer.

[Riley.]

i rip videos off youtube....some actually sound ok-ish but the majority are rubbish

havent tried lossless myself either....although 99% of the tracks i have either from CD or the iTunes store are decent

i have had one or two tracks have a slight hiss or even static that i think is coming through the left tweeter

as much as i love listening to CD's, i find the having x amount of songs/videos at your fingertips its just too convenient

[Riley.]

shiny_car, on Mar 4 2009, 07:54 PM, said:

would be even more interesting to try using an iDA model, or CD HU via USB. both these methods would bypass the analogue iPod circuitary, and go straight with digital via USB, relying on the 24-bit DAC in the HU.

cos an iDA has no CD transport, you would need to compare via a CD changer.

i think most dealers can do a good deal for an IDA unit + CD/DVD changer these days....i did love the look of the IDA X001 although i still think the 9887 has the best iPod navigation on the fly, although that might be because i knew the layout of the 9887 and my iPod intimately. I find myself looking at the screen of the 502 too much....even though i have set my new iPod up in a similar fashion you cant just "feel" the buttons like you would on a normal head unit

[HEKYEH]

Riley., on Mar 4 2009, 10:47 PM, said:

i rip videos off youtube....some actually sound ok-ish but the majority are rubbish

havent tried lossless myself either....although 99% of the tracks i have either from CD or the iTunes store are decent

i have had one or two tracks have a slight hiss or even static that i think is coming through the left tweeter

as much as i love listening to CD's, i find the having x amount of songs/videos at your fingertips its just too convenient

Definitely agree that the iPod is way more convenient...I have about 60GB on my iPod at the moment...if that was in CDs...that would be a fricken LOT!!!

But the loss in quality is very noticeable....

Edited by nidekcus, 04 March 2009 - 09:56 PM.

[audible]

Pulse-R

Nice link you found there. I'll quote the relevant section for reference;

Quote

What you may not know is that that the 4th and 5th generation iPods use a very high-quality internal Wolfson Microelectronics DAC (Wolfson DACs are used in quite a few high-end home audio CD players).For the music lover in us, all of these features are worthy of our attention. However for the audiophile in us, sonic performance is our highest priority and what Red Wine Audio has found is that the circuitry that follows the internal DAC (the analog line-out stage) needed to be improved in order to achieve true high-end performance.

We came up with a list of improvements to the sound quality that we believe are required in order to achieve true high-end performance (again, using WAV/Lossless music files):

Tighter, more articulate bass (not necessarily more bass quantity but much improved bass control and definition)

A richer, more seductive midrange

A less flat and more expansive imaging (the soundstage needs to open up and become more 3D more wide, more deep, and with a better sense of height in recordings that offer this level of resolution).

Improved transients/dynamics

More detail retrieval and overall transparency

Superior treble extension and sweetness, as well as better decay of long held notes and delicate harmonics

Most of the points are probably padding, but the main area that lacked the most SQ was bass followed by sibulance/stridence which off course is most noticable in the higher freq range.
Overall the ipod had a slightly "harsher" sound which I guess you could translate into most of the padding here.

I'll have to work out what Generation my ipod classic 80gig is, likely to be 4th or 5th given it's new. I have heard elsewhere that there is a wolfson in these things.

Shiny

So the Alpine IDA's connect to the ipod in a different method to the regular CDA/DVA head units? Makes sense given they are all fitted with 24 bit DAC's.

Might be time for an upgrade then shiny. I picked up the 80 gig i-pod for a good price as it's a run out model. 2053 tracks in all with around 14 gigs left over.
Only issue is that it's a hard drive and a drop from more than 3 inches onto a pillow will toast the hard drive, but the head unit charges the i-pod via the docking cable. It can live in the car and only have to come out for loading tracks.

Edited by audible, 05 March 2009 - 10:15 AM.

[Dogo]

Definitely the iPod circuitry my understanding is the same as Pulse-R - that the fullspeed iPod connection still uses analogue out from the Ipod. Else the Alpine unit wouldn't be able to decode tracks that are in a format that it couldn't normally play ( such as apple lossless )

Edited by Dogo, 05 March 2009 - 10:47 AM.

[EXOTICA]

...this might be a stupid question but does i-tunes give you the option to rip cds into your library using the lossless format?

[fuddbutter]

yeah you can set up in itunes how you want to rip them.

i dont use lossless, but i rip at 320kbps to rip all my songs.
still, you can hear a difference, there is compression and bits taken out.. pretty much say's it all there.

[audible]

EXOTICA, on Mar 5 2009, 03:03 AM, said:

...this might be a stupid question but does i-tunes give you the option to rip cds into your library using the lossless format?

Yep. From the top drop down, edit -> preferences then the advanced tab.
atm by my understanding you can't download lossless tracks from the itunes store.
I'm hoping that one day, that will change. In either case, for somebody like me with a 300+ cd collection, ripping discs via lossless will do me for now!

[ScottyDo]

audible, on Mar 5 2009, 11:12 AM, said:

Shiny

So the Alpine IDA's connect to the ipod in a different method to the regular CDA/DVA head units? Makes sense given they are all fitted with 24 bit DAC's.

Might be time for an upgrade then shiny. I picked up the 80 gig i-pod for a good price as it's a run out model. 2053 tracks in all with around 14 gigs left over.
Only issue is that it's a hard drive and a drop from more than 3 inches onto a pillow will toast the hard drive, but the head unit charges the i-pod via the docking cable. It can live in the car and only have to come out for loading tracks.

Sorry to Hijack Shiny's reply, but here was the official tech story we were told by the Apple and Alpine engineers who built the new generation of Alpine iPod head Units.

All of the Alpine head units that support USB for iPod (in other words non-Full Speed) tap into the data stream within the iPod before the iPod's DAC.

Yes the iPod has a very good quality DAC however by keeping the data transfer in the digital domain the Alpine units avoid multiple D/A and A/D conversions. Yes the Alpine units use high grade 24bit DAC (with the iDA-X100 using a K-Grade unit), but the real story is the limitation of the number of conversions from Digital to Analogue and back to Digital.

Think about it this way with Full Speed.
1) Within the iPod there is a DA conversion to allow Analogue Audio to be transfered to the H/U
2) The H/U then does an A/D conversion so that you can apply bass, treble, Xover etc
3) The H/U then does a D/A conversion to provide the audio signal to the pre-amp stage of the internal amplifier or out the the RCA's

So minimum 3 Conversions, and that's not including if you add an external processor like the PXA-H701, PXA-H100 or a Theatre amplifier...

Now with the USB for iPod H/U:
1) Data fromthe iPod is transfered digitally to the H/U
2) The H/U performs bass, treble, Xover etc
3) The H/U then does a D/A conversion to provide the audio signal to the pre-amp stage of the internal amplifier or out the the RCA's

So only 1 Conversion! Shorter and Cleaner Signal Path = Better Sound Quality!

Combine that along with Apple Lossless Compression (still supported via USB for iPod which requires a Codec in the H/U) and...away you go!

Now can you hear it once the vehicle is actually in motion?!?

Lucky for me I'm already Deaf so it doesn't matter LOL! I'll let the SQ Experts decide if this is all just a good marketing story or IF there is an audible advantage...

Enjoy!

Scott

[Dogo]

which units support "USB for iPod" ? I haven't heard of that feature before.

[shiny_car]

audible, on Mar 5 2009, 11:12 AM, said:

Shiny

So the Alpine IDA's connect to the ipod in a different method to the regular CDA/DVA head units? Makes sense given they are all fitted with 24 bit DAC's.

errr, what ScottyDo said.

the iDA series is best cos of the display. it utilises digital/USB connection. however, these models lack a CD transport, so are only designed for iPod and radio/tuner. you have to add a CD changer for CD playback.

all other alpine HUs that have a USB port can also utilise the digital data transfer. plus play CDs. a model with a BioLite highres display will also offer good text. i believe - though not 100% - a CD HU with USB still has full control over an iPod like the iDA. not sure if the iDA offers even more functionality.

a nice model is the CDA-9886i. CD HU with USB and BioLite display. whilst it also have the FullSpeed connection - which can also run an iPod - it has the limitations already discussed.

http://www.alpine.co...asp?modelID=360

[pyr0maniac]

Slightly off topic sorry, but does anybody know how an audio CD burnt from FLAC files would sound in comparison with the original recording? I imagine it would sound the same as FLAC is "lossless" also.