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Discussion Starter #1
I had an interesting conversation with a product rep yesterday. I was questioning him as to why no one has an optical iPod connection, considering that if you're doing the decode of the audio file inside of the head unit via USB, then you have the audio in a decoded digital stream and you should theoretically be able to drop it on the optical output with minimal effort.

He was telling me that Apple restricts them from outputting the audio of an iPod digitally, so they're forced to run it through the DAC in the head unit and sent it out analog.

Can anyone confirm or deny this? I'd love to know if it's true or not.

I realize this is all hearsay, so take it for what it's worth.
 

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Please re-type this as I can't understand this.
 

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Discussion Starter #4
Well the point wasn't about the technical details of how it can be done, I know that it's possible. My question to the rep was mostly around why it hasn't been done yet with their head unit line. His answer to me was that Apple restricts them from doing so as part of their agreement and that they wouldn't be an authorized partner if they went ahead and did it. I'm just wondering how true that was or if there's more to it, and thought someone on here might have more insight.
 

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I don't think its just Apple. If you plug in a USB drive you can't get the digital signal out either on those units.
 

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Apple restrict all sorts of stuff, I was speaking to the Pioneer rep about the App radio and pointed out that I thought the menu on it was $h!t and he agreed-he then went on to explain that the units they have at HO that actually work the way you'd want them to and Apple restrict the way they work!
 

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I think the rep is full of crap and simply talking out his ass.

my ipod uses a USB interface and since USB is digital, it is certainly NOT sending the signal in analog form. if they want the HU to send the signal on an optical or SPDIF format. they would just need to add the electronics to support it.

I think people are confusing the digital stream coming out of the ipod with what the optical or SPDIF stream looks like. it is not raw digital. it still has to be processed into a format that the receiving end can use.
 

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Discussion Starter #9
This can't be the case since the Wadia 170i home transport extracts the digital from the ipod and outputs digital SPDIF.
Interesting note from a review that I read on the Wadia 170i. It was from 2008 so it's very outdated, but it does highlight the fact that Apple does indeed restrict this sort of thing. (Or at least they did)
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To be clear from the start, the Wadia 170i transport includes no D/A converter. The special feature here simply is direct access to the iPod's files in the digital domain (just what models are compatible can be found under 'facts' at review's end). This bypasses Apple's compromised internal DAC. Why more such devices aren't presently available isn't due to lack of know-how but licensing. Apple is selective. Wadia seems first in line to have been granted a license.
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Apple restrict all sorts of stuff, I was speaking to the Pioneer rep about the App radio and pointed out that I thought the menu on it was $h!t and he agreed-he then went on to explain that the units they have at HO that actually work the way you'd want them to and Apple restrict the way they work!
As someone who runs a software company that has developed a few iPhone apps, they definitely love to restrict the way you do things, so I can't say that any of that is a surprise to me. I'm *sure* there's some hype in there as well, but all in all, Apple doesn't always play nice with people developing products for their systems.

I think the rep is full of crap and simply talking out his ass.

my ipod uses a USB interface and since USB is digital, it is certainly NOT sending the signal in analog form. if they want the HU to send the signal on an optical or SPDIF format. they would just need to add the electronics to support it.

I think people are confusing the digital stream coming out of the ipod with what the optical or SPDIF stream looks like. it is not raw digital. it still has to be processed into a format that the receiving end can use.
You're probably right, as reps do tend to talk a lot of smack... especially when their product is sub par.

And to your second point. If you're going direct USB then you should be doing the decoding yourself, correct? So you're getting an MP3 or AAC/Apple Lossless in an MP4 container. If you've got to decode that, then you're taking it down to a common format and then sending it to the DAC. maybe that's not the case, so let's say that you're getting a digital stream in some format from the iPod, it's doing the decoding but you're getting a digital stream via the USB. Same situation. I just don't understand why it's so difficult to go ahead and dump it out the SPDIF in a PCM stream.

It just doesn't make sense. If you went through the trouble to get it in digital, why hit the DAC in the deck, then fire it downstream into a processor, where you'd going to hit an ADC, then EQ/X-over, then back to another DAC, etc, etc. It's a ridiculous cycle and I can't figure out WHY they wouldn't do this when they already built the signal path for CD.

Maybe I just love a good conspiracy theory, but it seems like a high end vendor would have fixed this already.
 

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I read an article in Mobile magazine recently about this exact topic. Apple has VERY strict rules that manufacturers have to abide by if they want their product to be authorized to work with Apple products.


Sent from my iPhone using Tapatalk
 

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question is where do you want this digital signal to go to? what deck do you have that you aren't happy with the internal DAC (from USB connection to the iPod/iPhone)?

there are only a handful of processors that accept digital inputs (Audison bit one/ten) and not many decks that have digital outputs.

if you want to use a higher spec DAC than the one in the deck, you'll need to consider the above mentioned Wadia 170i, but a recent posting showed there is a cheaper dock.

Amazon.com: PURE i-20 Digital Dock for iPod/iPhone with Hi-Fi Quality Audio and Video Output: MP3 Players & Accessories

I'm currently researching about using this dock along with a home DAC I have and putting it into the glove box. The DAC will then output ANALOGUE to the deck. since all my processors/EQ are in the analogue domain, there is no duplication of D/A and A/D.

to connect this, I was thinking of a dock extender cable like this extending out of the glove box.

dockXtender: Dock Extender Cable for iPad, iPhone and iPod

Given the Pure i20 dock will have power, it'll charge my iphone and output the digital stream also to my Musical Fidelity V-DAC --> aux RCA input on the deck
 

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You're probably right, as reps do tend to talk a lot of smack... especially when their product is sub par.

And to your second point. If you're going direct USB then you should be doing the decoding yourself, correct? So you're getting an MP3 or AAC/Apple Lossless in an MP4 container. If you've got to decode that, then you're taking it down to a common format and then sending it to the DAC. maybe that's not the case, so let's say that you're getting a digital stream in some format from the iPod, it's doing the decoding but you're getting a digital stream via the USB. Same situation. I just don't understand why it's so difficult to go ahead and dump it out the SPDIF in a PCM stream.

It just doesn't make sense. If you went through the trouble to get it in digital, why hit the DAC in the deck, then fire it downstream into a processor, where you'd going to hit an ADC, then EQ/X-over, then back to another DAC, etc, etc. It's a ridiculous cycle and I can't figure out WHY they wouldn't do this when they already built the signal path for CD.

Maybe I just love a good conspiracy theory, but it seems like a high end vendor would have fixed this already.
in my case, it uses the ipod as a simple data source. the file is transfered into the HU where the HU does the decoding, then runs it through a DAC for RCA and internal amplifier duty. if it had an optical or SPDIF output then it could take that decoded stream and run it out of either of those interfaces.
 

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What he said^. Don't worry about it. It is all digital when using USB with it not being tampered.
 

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Discussion Starter #14
question is where do you want this digital signal to go to? what deck do you have that you aren't happy with the internal DAC (from USB connection to the iPod/iPhone)?

there are only a handful of processors that accept digital inputs (Audison bit one/ten) and not many decks that have digital outputs.

if you want to use a higher spec DAC than the one in the deck, you'll need to consider the above mentioned Wadia 170i, but a recent posting showed there is a cheaper dock.

Amazon.com: PURE i-20 Digital Dock for iPod/iPhone with Hi-Fi Quality Audio and Video Output: MP3 Players & Accessories

I'm currently researching about using this dock along with a home DAC I have and putting it into the glove box. The DAC will then output ANALOGUE to the deck. since all my processors/EQ are in the analogue domain, there is no duplication of D/A and A/D.

to connect this, I was thinking of a dock extender cable like this extending out of the glove box.

dockXtender: Dock Extender Cable for iPad, iPhone and iPod

Given the Pure i20 dock will have power, it'll charge my iphone and output the digital stream also to my Musical Fidelity V-DAC --> aux RCA input on the deck
It's mostly just me being picky.
1) I want head unit control. Touching the iPod isn't an option.

2) When the PXA-H800 hits the states, I'll have one. :) I have a 701 now that's optical from my DHA-S690 DVD changer, but my head unit doesn't have the optical pickup or I'd be using that as well. (I have a W407 with no CD player) I'm about to start a build in my second car where I'll be using a BitOne and Audison Voce amplifiers, with digital signal paths. Granted, AI-Net is actually a nice analog system, but I want more. Yes, I know... I'm being ridiculous.

3) I still buy all of my CDs and rip them myself into AAC using Exact Audio Copy and Nero's AAC encoder, so I'd appreciate it if my radio paid the same attention to quality that I do, not just shove it through whatever the cheapest route is. Again, I'm being ridiculous but it's just irritating to see that the vendors won't put an effort into making this a reality and won't cough up a real reason as to why.

4) If I did a PC in the car, I'd have an optical signal path that would work for all of my music, but I'd really rather have something designed with audiophiles in mind. :)
 

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Discussion Starter #15
in my case, it uses the ipod as a simple data source. the file is transfered into the HU where the HU does the decoding, then runs it through a DAC for RCA and internal amplifier duty. if it had an optical or SPDIF output then it could take that decoded stream and run it out of either of those interfaces.
I have a W407, so I'm in the same boat as you. (If your sig is current) This is actually the unit that set me off about the whole thing, since it's claim to fame was this new and improved signal path for the iPod. But in the end, it still fires through the DAC and we're left without optical with no explanation or change to buy a more expensive unit that has it. I went from a CDA-117 to a W407 and actually think the 117 sounded better when connected via AI-Net to the 701. (I also had an H100 as well. I've tried both with the same results)

Again, I get that I'm being picky here, and my W407 doesn't sound bad even though the 701 has noisy inputs, it's still impressive. I just want more, that's all. So, when the H800 appeared and I knew I could finally clean up the processing stage of my system, I went on a quest to figure out how to clean up the signal source as well.
 

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P99RS is the solution to most of these problems. Digital stream from ipod to deck, with plenty of processing onboard. No DA-AD-DA conversion, just one DA stage, post processing, in the deck.
 

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As someone who runs a software company that has developed a few iPhone apps, they definitely love to restrict the way you do things, so I can't say that any of that is a surprise to me. I'm *sure* there's some hype in there as well, but all in all, Apple doesn't always play nice with people developing products for their systems.
Go try an ipod on an AVH3300BT/6300BT etc and then try the SPH-DA01 and you'll quickly see the AVHs ipod menu is far superior.

The SPH you can't "slide" your artist/album/tracks up and down, or select by touching the track name-you have to hit a little up/down arrow and then an "ok" button-Apple restricted this as they believed it would be distracting to use the "slide" function while driving.

I'd warrant their, more irritating, system provides more of a distraction as while it looks like you should be able to do it the way you'd expect the way you have to do it makes you pause to think and then "concentrate" harder on changing your track than driving.

Another interesting Apple fact: £12 per unit to get the Apple/Made for ipod sticker for your box-quite a % when ipod charge and control radios sell for £70.00!
 

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Something that worth to consider :
1. As said before, knowing the circuit design then only we can know how to deal with this...
2. connecting to our equipment using analog or digital connections will change how the DSP perform.... Just take an AV amp for example, using RCA, the chain on that amp will be analog > digital > DSP > analog while using optical the chain will be digital > DSP > analog and it will be louder....

At the end of day, 2 equipment playing important part, the iPod and the AV amp(in this case)... I can say with a special adaptor the iPod will send out "digital" signal or another way round because the AV amp will behave differently on the source of the signal...
 
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