Audio streaming via bluetooth

Took delivery of my new 328xi sedan a coupel days ago, with the premium sound package. My dealer claims that it is possible to stream bluetooth from an iPhone4 via bluetooth. While my phone works perfectly well receiving and making calls via bluetooth, I cannot find any way to stream audio. Any assistance would be most appreciated.

Somehow if you do not have iDrive there's no way of enabling the Bluetooth audio, although the feature is indeed there -as long as your car is also equipped with Assist.

I have not seen anybody at any forum clarifying what is going on with this.

Thanks for the reply. I don't have iDrive. Rats, can't take the cables. It is such basic functionality - I wonder why it is not basic to all BT equipped vehicles?

i am on the new iDrive and i'm interested in the streaming audio from my iphone 4 via bluetooth also... please do tell!!

I spoke to BMW Canada - as noted elsewhere in the forum, all 3 series vehicles built after Sept 2010 are equipped to stream audio via bluetooth (even in the absence of iDrive apparently). The vehicle the I received Feb 1, as was assured was being built, was in fact built March 2010(!), so it does not support streaming.

Audio streaming via Bluetooth, while convenient, results in compromised sound quality. A direct digital connection or even an analog one via the AUX jack will sound considerably better.

Originally Posted by jmsent

even an analog one via the AUX jack will sound considerably better.

Perhaps this should be true but in practice I've found there is always noise via AUX. In my car in particular, the Bluetooth connection results in sound much superior to the AUX. Even my wife complained about the quality via AUX.

With a Windows 7 phone and a Zune pass the Bluetooth streaming is the bomb. I have the whole Zune catalog in my car at all times.

Originally Posted by jbrowne

Thanks for the reply. I don't have iDrive. Rats, can't take the cables. It is such basic functionality - I wonder why it is not basic to all BT equipped vehicles?

Yeah, this stinks and I'm not sure why BT streaming is not supported in a non-iDrive vehicle. I tried everything to get it to work on my post Sept 3 to no avail. Come on BMW, unleash this to all, it can't be that hard.

Originally Posted by jmsent

Audio streaming via Bluetooth, while convenient, results in compromised sound quality. A direct digital connection or even an analog one via the AUX jack will sound considerably better.

Wrong. A2DP profile (BT profile used for audio streaming) supports *at least* 44.1 kHz/16 bit/stereo, which is CD audio format. Many A2DP implementations support even higher resolutions.

Originally Posted by vadim

Wrong. A2DP profile (BT profile used for audio streaming) supports *at least* 44.1 kHz/16 bit/stereo, which is CD audio format. Many A2DP implementations support even higher resolutions.

CD audio format is uncompressed PCM. I haven't found any literature stating that A2DP supports this bandwidth.
From the Bluetooth site
"A2DP defines the protocols and procedures that realize distribution of audio content of high-quality in mono or stereo on ACL channels. The term “advanced audio,” therefore, should be distinguished from “Bluetooth audio,” which indicates distribution of narrow band voice on SCO channels as defined in the baseband specification.

This profile relies on GAVDP. It includes mandatory support for low complexity subband codec (SBC) and supports optionally MPEG-1,2 Audio, MPEG-2,4 AAC and ATRAC.

The audio data is compressed in a proper format for efficient use of the limited bandwidth. Surround sound distribution is not included in the scope of this profile."

Not saying you're wrong, but I haven't found anything to support your claim. Also, the high end home devices I've auditioned that feature blue tooth audio streaming have all used compression schemes, and sound decidedly inferior to e.g., a USB or WI FI implementation.

i was looking for a wwf throwdown or an answer... all i got was this empty box to write in. please continue discussion, if you will.

Originally Posted by jmsent

CD audio format is uncompressed PCM.

CD audio format (CD-DA) uses 44.1kHz/16bit/Stereo.

See http://makbit.com/articles/cd-overview.pdf, page 2.

I haven't found any literature stating that A2DP supports this bandwidth.
From the Bluetooth site "A2DP defines the protocols and procedures that realize distribution of audio content of high-quality in mono or stereo on ACL channels. ...
Not saying you're wrong, but I haven't found anything to support your claim. Also, the high end home devices I've auditioned that feature blue tooth audio streaming have all used compression schemes, and sound decidedly inferior to e.g., a USB or WI FI implementation.

See http://www.bluetooth.com/SiteCollect...P_SPEC_V12.pdf, paragraphs 4.3.2.1 and on.

"...For the decoder in the SNK the sampling frequencies 44.1 kHz and 48 kHz are mandatory to support. The encoder in the SRC shall support at least one of the sampling frequencies of 44.1 kHz and 48 kHz..."

I don't want to break this down any further, all the info is there.

The bottom line is that BT A2DP has enough bandwidth to deliver streamed MP3 audio in a lossless manner. Depending on implementation and source file format, it may or may not require additional transcoding of audio material, unlike Y-cable (which does introduce D-A in the iPod/iPhone and A-D in the car's stereo). So, BT A2DP is at least as good as analog connection, or better. The best option would still be using a USB stick and 44.1/16/S .WAV format. But even then, A2DP is capable of delivering that quality, so it is not the bottleneck. It is just that there are no A2DP-enabled sources (I may be wrong here, though) that could stream audio of high quality.The iPod/iPhone certainly is not up to par in this regard.

However, if we are talking about MP3, even if the highest bitrate encoding is used (320 kbps), it still is a lossy format which makes this discussion rather pointless.

Just use your iPhone's dock connector cable and plug it into the USB port in the center console.

Boom, done.

Originally Posted by meeksdigital

Just use your iPhone's dock connector cable and plug it into the USB port in the center console.

Boom, done.

Yes, although you lose the ability to browse directories as iThings store music files under meaningless names.

Originally Posted by vadim

Yes, although you lose the ability to browse directories as iThings store music files under meaningless names.

??? no idea what you're talking about.

Originally Posted by vadim

Depending on implementation and source file format, it may or may not require additional transcoding of audio material, unlike Y-cable (which does introduce D-A in the iPod/iPhone and A-D in the car's stereo). So, BT A2DP is at least as good as analog connection, or better. The best option would still be using a USB stick and 44.1/16/S .WAV format. But even then, A2DP is capable of delivering that quality, so it is not the bottleneck. It is just that there are no A2DP-enabled sources (I may be wrong here, though) that could stream audio of high quality.The iPod/iPhone certainly is not up to par in this regard.

However, if we are talking about MP3, even if the highest bitrate encoding is used (320 kbps), it still is a lossy format which makes this discussion rather pointless.

just a couple of points of clarification - the 2011 LCI 3-Series BMW's (the ones that don't use the Y-cable, but only the standard 30pin ipod to USB cable) do digital audio-over-USB (i believe) so would not be subject to the D-A/A-D issue you mention. in addition, when i last checked, iPods can store and play back uncompressed WAV files, so if one were looking for the highest quality audio (in a 2011 LCI car with USB/iPod connectivity in the armrest) then playing a WAV file through the USB connector over the single white USB to 30pin cable would (should?) provide the highest quality audio.

Originally Posted by vadim

It is just that there are no A2DP-enabled sources (I may be wrong here, though) that could stream audio of high quality.The iPod/iPhone certainly is not up to par in this regard.

Tell me more. Why isn't the iPhone up to the task? Is this about processing power or something else?

Originally Posted by craigrow

Tell me more. Why isn't the iPhone up to the task? Is this about processing power or something else?

I believe it is the processing power more than anything else. I have a Blackberry Audio gateway which is a BT streaming receiver connected to a home stereo. It works rather well most of the time, except for instances when the iPhone is overloaded (e.g. its screen is getting locked down or unlocked, or it is retrieving email, etc.) At those moments the audio stream may get interrupted, and often the pitch of the sound starts to fluctuate as in an old worn-down cassette player. This leads me to believe that the phone's processor simply chokes on the load it is not meant to handle. The same Blackberry gateway, when used with a laptop outfitted with a USB BT adapter, produces a perfectly good sound with no pitch variations and no interruptions.

Originally Posted by robingo

just a couple of points of clarification - the 2011 LCI 3-Series BMW's (the ones that don't use the Y-cable, but only the standard 30pin ipod to USB cable) do digital audio-over-USB (i believe) so would not be subject to the D-A/A-D issue you mention. in addition, when i last checked, iPods can store and play back uncompressed WAV files, so if one were looking for the highest quality audio (in a 2011 LCI car with USB/iPod connectivity in the armrest) then playing a WAV file through the USB connector over the single white USB to 30pin cable would (should?) provide the highest quality audio.

All this is correct. In this regard the iPod is no different than a dumb USB stick, as all functionality will move to the car's audio system, leaving the iPod as a mere USB storage device. However, unlike the iPod, the iPhone can not be interfaced with the car over a USB cable alone - it does require a Y-cable, the audio being transferred over its analog wire; hence the extra A-D/D-A.

Originally Posted by meeksdigital

??? no idea what you're talking about.

When sound files are imported into an iPod or an iPhone, their original names are lost. The iThing will store them under its own names which are meaningless. See the picture attached. It shows a raw file structure of an iPhone. The files on the right are actual songs, but what they are one can not tell until they are loaded in a media player which, of course, will read the tags and show all the info - Author, Album, Song, etc.

Originally Posted by vadim

CD audio format (CD-DA) uses 44.1kHz/16bit/Stereo.

See http://makbit.com/articles/cd-overview.pdf, page 2.

Please. I taught CD theory to engineering students. I don't need an internet document to tell me how it works.

See http://www.bluetooth.com/SiteCollect...P_SPEC_V12.pdf, paragraphs 4.3.2.1 and on.

"...For the decoder in the SNK the sampling frequencies 44.1 kHz and 48 kHz are mandatory to support. The encoder in the SRC shall support at least one of the sampling frequencies of 44.1 kHz and 48 kHz..."

I don't want to break this down any further, all the info is there.

Yes, so perhaps you should be a bit more careful with your claim that sampling of 44.1kHz and 16 bit word length are the only the only specs that define "CD quality"

The bottom line is that BT A2DP has enough bandwidth to deliver streamed MP3 audio in a lossless manner.

So A2DP can deliver a lossy format in a lossless manner. IOW, it doesn't further degrade already degraded data. MP3 is, itself, not lossless. But CD format is. So you can't deliver CD quality over A2DP, which is what you claimed.

Depending on implementation and source file format, it may or may not require additional transcoding of audio material, unlike Y-cable (which does introduce D-A in the iPod/iPhone and A-D in the car's stereo).

The quality of the DA in the iPod/Iphone is in fact quite good. Try an Apple Lossless file on it connected through the aux jack and see if you can hear any difference between it and the same recording played on the CD deck built into the radio. There's also nothing holding back the quality of the analog AUX input that I can see, unless you use a lousy interconnect cable that allows noise to intrude.

So, BT A2DP is at least as good as analog connection, or better.

Nope.

The best option would still be using a USB stick and 44.1/16/S .WAV format. But even then, A2DP is capable of delivering that quality, so it is not the bottleneck.

Nope. Lossy is not as good as lossless no matter what you say.

However, if we are talking about MP3, even if the highest bitrate encoding is used (320 kbps), it still is a lossy format which makes this discussion rather pointless.

But we weren't talking about MP3, we were talking about CD.

From my experience (post Sep 2010 with iDrive), bluetooth audio streaming from iPhone (3G, 3.1.3) has NOT been useful.
- Music skips constantly with MP3 compression at 128, 192, and 320 kbps bit rates, and AAC 256 kbps.
- iDrive DO NOT display music list or album cover. But you can fwd/rev with controls on steering wheel.
If anyone has better experience, please advise us.

Originally Posted by craigrow

Perhaps this should be true but in practice I've found there is always noise via AUX. In my car in particular, the Bluetooth connection results in sound much superior to the AUX. Even my wife complained about the quality via AUX.

With a Windows 7 phone and a Zune pass the Bluetooth streaming is the bomb. I have the whole Zune catalog in my car at all times.

If you're using the Aux jack, make sure to turn the volume on the ipod down; otherwise you get clipping.

Does the BMW iDrive support Android phones? My build was pre-sept/2010 so I guess bluetooth playback is out of the question?

My iPhone 4 and sept 2010 production 328 with iDrive work well through Bluetooth. The plus is to stream audio from apps. I have economist subscription, great to hear audio articles through car speakers. Very nice.