Head unit supporting USB audio?

[casm]

i guess. i have my ipod in my glove box (ipod cable) and the aux in (from the rear of the HU) coming up into my ashtray where my phone usually lives.

Understood. And that may be what I end up doing as well, but as I'm also looking at this in part as a component of a larger plan to (effectively) build in USB infrastructure, I'm keen to keep to USB if possible as a one-shot solution.

I have used a lot of audio to usb adapters, but the thing most people don't really realize is that the adapter is actually a sound card and has to be set up and recognized by the computer.

Correct, this is my understanding as well. However:

I don't ever remember seeing an actual protocol for straight audio over usb.

It's entirely possible that I'm not completely understanding the documents I've been going through, but my understanding is that it's possible to send data frames over USB that are specifically identified as containing audio. Further to that:

I have seen the protocol that allows the operating system to use the usb adapter as a sound card. That being said, you head unit would have to behave like a mother board and have drivers loaded.

This is where I'm thinking that the drivers may be necessary: if the standard for moving the audio frames over the wire only specifies the frame format but not the format of the data in the frames, then it would make sense that drivers may be needed to interpret the data inside the frame (though it seems like something that could potentially be handled by an application as well).

Remember that I'm just concerned with moving the audio stream over USB in a format that the head unit can understand when it receives it - the processing of the audio will already have been done when it hits the wire, so all that needs to happen is that the phone squirts a frame to the head unit, the head unit strips the frame from the data within it, and then plays that data as digital audio.

What I'm hoping for is a lowest-common-denominator method of achieving this that both devices support, and from the reading that I've done it looks like there may be something there that covers this. However, I really need to dig into it a bit more deeply to get a decent grasp on it; failing that, there may be something out there that can put my phone into an iPod simulation mode as far as audio connectivity and output is concerned, which would make this a possibility on stock iPod interfaces.

 

[casm]

Bluetooth may have just obviated the issue.

http://www.amazon.com/Sprint-Bluetooth-Receiver-Connector-Speakers/dp/B003V1619E

That's the Anycom FIPO Bluetooth v2.0 Stereo Receiver w/Dock Connector. Looks like it plugs into the iPod connector and lets you do AD2P Bluetooth streaming over the iPod interface, which is OK as a workaround for me. Price is right, too. Now I just have to find somewhere with it in stock.

 

[WebDog]

I did this with a sony HU with AUX box that had USB audio in, I had a computer connected to it and boy did that sound good, eliminating any analog sound cards got rid of my alternator noise.

Bluetooth is nice but I find it not as clear as hard wired.

 

[WebDog]

Here you go http://www.crutchfield.com/p_158XA300/Sony-XA-300.html?tp=1672

USB in for sony head units

 

[casm]

Bluetooth is nice but I find it not as clear as hard wired.

That's actually not much of an issue in this case - the majority of the audio streams I'm intending to send to the head unit are encoded at 128Kbps or less, so a slight loss in quality won't really matter since it's not great to begin with. As long as it's listenable it'll be fine.

 

[casm]

Just for anyone who may have been following this: I ordered the Anycom iPod Bluetooth adapter from eBay; item page is here. It was the best in-stock deal I found on it at $19.99 with free shipping and they have a bunch ready to ship; I'll post results in a few days when it's in.

 

[asp]

Sweet, good luck and be sure to let us know how it works.

I might be able to have my girlfriend's brother plug his HTC incredible into my head unit tonight or tomorrow.

 

[Blue 97 XJ]

ok i was too lazy to read the entire thing but i am running the pioneer ub4000 and i have a passport hard drive in the glove box with ALL of my music on it (over 65 gigs), i did need to wire up something extra so supply enough power but it works great! and i can still plug in a thumb drive if i want.

 

[casm]

ok i was too lazy to read the entire thing

Which means that you don't have the first clue about what is actually being discussed here.

but i am running the pioneer ub4000 and i have a passport hard drive in the glove box with ALL of my music on it (over 65 gigs), i did need to wire up something extra so supply enough power but it works great! and i can still plug in a thumb drive if i want.

Completely unrelated to the topic. Had you bothered to read the thread, you'd understand exactly why you're getting both the tone and quality of reply that you are right now.

 

[asp]

So today I hooked up a HTC incredible to my Alpine CDA 117.

The phone gave 2 options:
-charge only
-hard drive mode

Charge let the phone still do everything it normally could.

Hard drive mode renders the phone nearly, but not totally useless. The head unit saw the phone and played a file... but all it could find was the 'facebook pop' sound. Something to do with facebook notifications...

We were unable to play music off of the phone.

 

[casm]

The Anycom FIPO Bluetooth-to-iPod adapter showed up today. Verdict: the price is right and it does exactly what it's supposed to. Buy one

My setup is an older Alpine CDA-9856 head unit with the integrated iPod adapter and cable. It seems to work fine with this hardware, but I did run across posts from a few folks with other brands of stereo for whom this adapter didn't work. I took a gamble and it came up OK, but YMMV. FWIW, my initial test case with it was in a 5-year-old iHome clock/radio with iPod adapter and it also worked in that without issue.

Pairing was a breeze. The unit's default PIN is 0000, so Android automatically detected it as a headset and paired to it with no PIN entry required; once paired, it's locked to the device that it's paired with which should prevent contention if multiple devices try to pair to it simultaneously. It is possible to force a de-pair if necessary, but I only really glanced at that part of the manual so don't remember specifics on it. Feeding it a PIN of 9999 to do this sticks in my memory, though.

The unit itself is tiny - about the length & width of two postage stamps and maybe one-third of an inch thick. If you have a device that requires the iPod to fit into a recess in order to dock, this should easily fit that space with room to spare.

The only real caveats I've noticed about it (in a grand total of three hours' ownership) is that it doesn't normalise audio to line level, so you have to set the volume on the head unit and/or phone on a per-app basis. Also, it looks as though it passes through some data from the head unit about the state of the head unit controls, but the app needs to be aware of it in order to work with them. In XiiaLive, for example, the app responds to the head unit's play/pause button (but not any of the others); in Scanner Radio, though, it doesn't respond to any. Artist / Playlist / Title search, etc. do not seem to be functional, but that's not a big deal.

Sound quality is what I was expecting it to be: listenable. The streams I've been feeding it are 128Kbps (music and voice), and they're no worse than what I get on the same head unit over XM. There is some artifacting, but given that the streams are 128Kbps and there's no way to know what the source feeding the stream was originally encoded at, that's to be expected. Also, we only have EDGE speeds on GSM around here with drops to GPRS in places: audio was affected by this but as that's a network issue it can't be pegged on the Anycom.

Overall I'm happy with it thus far. Still need to make sure that it operates with the Griffin Road Trip iPod cradle/charger/FM adapter I have for use in vehicles without iPod integration, but I'm fairly confident that it'll work. The eBay sale that I purchased it from appears to have bumped the price up by $5 since I picked it up, but shipping's still free so even at $25 it's a good deal - and I ordered it from them in CA and it was in VA three business days later. Recommended.

 

[casm]

Gah. Misfire. Ignore.

 

[asp]

That's pretty slick. Sounds like an awesome solution to the problem. If I ever get a fancy phone maybe I'll go this route.

 

[casm]

That's pretty slick. Sounds like an awesome solution to the problem. If I ever get a fancy phone maybe I'll go this route.

It's definitely pretty nifty, and I really like the fact that it just does one thing and does it well. After driving around with it in there all day, it's turned out to be a good find. Bonus: I just found out that it does also work with the Road Trip FM transmitter, so it's a success all around.

 

[anthrax323]

This thread has made my brains hurt so I skipped the middle and jumped right to the end...

The Bluetooth receiver idea that you followed is what my buddy did in his Discovery - he only plays audio from an iPhone or iPad, and never listens to the radio. Thus, he got rid of his 1DIN head unit in favor of a custom-made iPad mount, and just has a little Bluetooth receiver hooked up to a 4-channel stereo amplifier. Very elegant and simple.

Now, a few comments on the USB thing... Although it is published within the USB spec (as you pointed out), I have yet to see any devices actually implement this. Everything I've ever seen is simply power, ground, and data - never audio. The iPhone's dock connector does allow you to accomplish this if desired, but you'd need to make a custom cable. From there, it'd be up to you to make sure any devices you want to use with it are capable of being compatible with it (FWIW, every dock connector/pinout I've looked at in recent history for media devices like Droids and iPhones does make provisions for raw line-level stereo output - just custom cabling from there).

I ran into a similar dilemma... I wanted to integrate my iPhone, but not relinquish controls to the head unit. I ended up buying a Kenwood KDC-X994, which gives you an "iPod By Hand" mode option (which prevents the head unit from interfering with the iPhone at all).

Strangely, though, I've given iPod controls back over to the head unit for the sake of changing songs and pausing more easily when driving (so I don't have to take my eyes off the road). This works fine for me since it's pretty much always on random. I became far more comfortable with the feature the moment I realized that it only took control over the iPod app itself - I can still play music through Pandora, and audio from other apps is channeled through the head unit as desired.

Oh yeah, and the Bluetooth receiver in the X994 is flawless - on rare occasions, I'll get the itch to pair my laptop with the receiver for audio output. Quite a convenience.

 

[casm]

The Bluetooth receiver idea that you followed is what my buddy did in his Discovery - he only plays audio from an iPhone or iPad, and never listens to the radio. Thus, he got rid of his 1DIN head unit in favor of a custom-made iPad mount, and just has a little Bluetooth receiver hooked up to a 4-channel stereo amplifier. Very elegant and simple.

I thought about going this route, but my concern is not having an AM/FM radio; being reliant on the cell network to get local info just doesn't sit well with me, and my lifetime XM subscription doesn't include streaming to the phone. Now that we've got Bluetooth-capable head units out there that can do all of that and ditch the CD player in the process (which I think I've maybe used a half-dozen times in six years), integration options are definitely getting better.

Now, a few comments on the USB thing... Although it is published within the USB spec (as you pointed out), I have yet to see any devices actually implement this.

The only one I've found that does claim to do it is the Griffin 4-port USB audio hub - but that was a) on the market nine years ago and seems to have disappeared without a trace, and b) it's unclear if anything that could plug into it ever took advantage of its capabilities.

I'm actually kind of surprised that USB audio support hasn't gained more ground in the marketplace - given how reliant devices have become on USB, it seems like the sort of thing that would make sense for manufacturers to start pushing compatibility with.

Everything I've ever seen is simply power, ground, and data - never audio. The iPhone's dock connector does allow you to accomplish this if desired, but you'd need to make a custom cable. From there, it'd be up to you to make sure any devices you want to use with it are capable of being compatible with it (FWIW, every dock connector/pinout I've looked at in recent history for media devices like Droids and iPhones does make provisions for raw line-level stereo output - just custom cabling from there).

Yup, found those out as well in researching. What I was trying to find was more of a one-size-fits-all approach, and the Bluetooth adapter turned out to be the most realistic way of accomplishing it. One thing I really wanted to avoid was having to deal with custom cables or similar that may or may not have been portable between vehicles; neither of the Subarus or the Crossfire have or are likely to get that ability, and all of them have head units by different manufacturers.

I ran into a similar dilemma... I wanted to integrate my iPhone, but not relinquish controls to the head unit. I ended up buying a Kenwood KDC-X994, which gives you an "iPod By Hand" mode option (which prevents the head unit from interfering with the iPhone at all).

That's good to know: I may be picking up another Subaru here shortly with no radio in it, and may as well just get something that doesn't require moving FM transmitters between vehicles when it comes time to outfit it.

Oh yeah, and the Bluetooth receiver in the X994 is flawless - on rare occasions, I'll get the itch to pair my laptop with the receiver for audio output. Quite a convenience.

Also good to know, as I'm planning on running audio from one of my ham rigs to the laptop for recording. They already work with the Anycom unit, but being able to monitor that through the vehicle speakers would be a huge plus. Apple makes great displays, but their laptop speakers leave a lot to be desired.