Bluetooth HUs - audio quality?

[vebmetal]

I am shopping around for an ICE system for my Estilo, and I came across some HUs which have Bluetooth. Seems like it has two uses - to act as a handsfree option for your cell phone, and to be able to stream music to the system (i.e. from your mobile phone).

I tried the streaming option at a dealer, but the audio quality was terrible - most likely because it was being streamed over bluetooth, though there is a small chance the audio file was not very good in the first place. (Also my phone does not have a2dp - that could be the reason).

Does anyone have any experience with these? If so, what is your opinion? Should one go for Bluetooth HUs or is it a frivolous and impractical expense?

[hemanthisgreat]

Originally Posted by vebmetal

I am shopping around for an ICE system for my Estilo, and I came across some HUs which have Bluetooth. Seems like it has two uses - to act as a handsfree option for your cell phone, and to be able to stream music to the system (i.e. from your mobile phone).

I tried the streaming option at a dealer, but the audio quality was terrible - most likely because it was being streamed over bluetooth, though there is a small chance the audio file was not very good in the first place. (Also my phone does not have a2dp - that could be the reason).

Does anyone have any experience with these? If so, what is your opinion? Should one go for Bluetooth HUs or is it a frivolous and impractical expense?

it depends on the head unit u are buying and also ur phone. i have a pioneer 7850bt headunit. i have played mp3 music on the car audio through bluetooth on the phone. it plays really well. and this HU works really well when you use it to connect it to ur phone to make and receive calls. its really helpful if u listen to loud music, as when there is an incoming call, the music switches off and you will be able to speak through the mike and listen through the car speakers. its most useful if u are alone in the car, as everyone will be able to listen to the conversation on the speakers.

[devarshi84]

Delphi grundig X350BT

Clarion FB276Bt

JVC KD-BT1

Pioneer 7850BT (Dont know if it streams music)

Blaupunkts have BT but dont stream music.

Quality shouldnt be a problem if the phones support A2Dp. BTW if your phone doesnt have A2Dp, how did you play music in the first place?

[rocksterraghu]

Bluetooth has a total bandwidth of 721kbps (kilo bits per second not bytes, if you're not a techie) of data/voice which should be more than sufficient to stream the audio files on your phone. The question is, how capable is your phone and your HU.

I once tried streaming audio from my phone to my laptop that comes bluetooth enabled through the 'handsfree' port and the quality was pretty sad. So, I guess you need to stream stereo audio, the full bitrate from your phone to achieve the quality you desire. I really have no experience with streaming stereo audio.

[hemanthisgreat]

Originally Posted by devarshi84

Pioneer 7850BT (Dont know if it streams music)

i have this HU. it does stream music. it has got a feature called bluetooth audio, for streaming music from any external bluetooth device.

[devarshi84]

how much did it cost you?

[hemanthisgreat]

Originally Posted by devarshi84

how much did it cost you?

the pioneer 7850bt HU cost me 18500

[santosh.s]

Nice thread! I was actually very interested in getting details about bluetooth audio streaming.

Originally Posted by devarshi84

Quality shouldnt be a problem if the phones support A2Dp. BTW if your phone doesnt have A2Dp, how did you play music in the first place?

I only know that A2Dp is some thing which lets you stream some "good quality & stereo" music(??). Can somebody please give more details about it-

1. Does it transfer audio as raw samples (after decoding), or it just sends it as data files, leaving decoding for the destination device?

2. Max bit-rate? (already answered by Raghu: 721kbps). Is this rate guaranteed across all BT variants?

3. If it is raw audio, what is max sampling rate, bits per sample and number of channels? (with above bitrate, CD quality (2x16bit@44.1KHz) is not possible at all)

4. Is there any method to stream music other that A2Dp (most likely inferior, mentioned in fine prints in the manuals if there is no A2Dp support)?

[rocksterraghu]

Originally Posted by santosh.s

Nice thread! I was actually very interested in getting details about bluetooth audio streaming.



I only know that A2Dp is some thing which lets you stream some "good quality & stereo" music(??). Can somebody please give more details about it-

1. Does it transfer audio as raw samples (after decoding), or it just sends it as data files, leaving decoding for the destination device?

2. Max bit-rate? (already answered by Raghu: 721kbps). Is this rate guaranteed across all BT variants?

3. If it is raw audio, what is max sampling rate, bits per sample and number of channels? (with above bitrate, CD quality (2x16bit@44.1KHz) is not possible at all)

4. Is there any method to stream music other that A2Dp (most likely inferior, mentioned in fine prints in the manuals if there is no A2Dp support)?

CD quality (44.1 kHz 16 bit Stereo) audio requires 1411.2 kbps bandwidth in the transmission medium. The highest bitrate achievable over Bluetooth is 721Kbps. So, a codec, Subband Codec (SBC) originally developed by Philips is used which ensures that a player will compress the CD-quality-stereo file into a size that fits into the Bluetooth bandwidth, and the headphone or speaker on the other side decompresses the streamed audio.

Bluetooth specifies the Advanced Audio Distribution profile (A2DP), which define procedures that are specific to streaming of audio content over Bluetooth. Devices that implement the A2DP profile can play one of two roles, Source (player) of an audio stream or Sink (headphone or speaker) of the audio stream. This profile also provides for Quality-of-Service maintenance to ensure high quality audio transmission, through mechanisms such as Jitter buffers and variable bit-rates.

Also note that bluetooth also supports other optional Codecs such as MPEG-1,2 Audio, MPEG-2,4 AAC, and the ATRAC family.

[vebmetal]

So I assume my problem is basically that my phone doesn't have a2dp. Well that's ok since I don't really plan on storing music on my phone (which also means that I shouldn't really care about Bluetooth on my HU).

But for purposes of information, how is the sound clarity on Bluetooth as compared to streaming via a FM transmitter (like the iTrip) ?

[rocksterraghu]

Originally Posted by vebmetal

So I assume my problem is basically that my phone doesn't have a2dp. Well that's ok since I don't really plan on storing music on my phone (which also means that I shouldn't really care about Bluetooth on my HU).

But for purposes of information, how is the sound clarity on Bluetooth as compared to streaming via a FM transmitter (like the iTrip) ?

I don't have first hand experience, so I can't compare the two. However, looking at the two technologies, I think Bluetooth would be a better choice.

If you really want to buy an FM transmitter, please don't buy products like Griffin iTrip, they are really really bad. I bought an iTrip (Griffin) for about 2k and used it for 5 minutes and NEVER EVER used it again. You may consider superior products like - harman/kardon Drive+Play iPod interface, which I guess Sam uses in his Lancer .

Honestly, there are better ways of playing music in your car, like CDs, full speed cables connecting your audio source to the HU or USB drives for example. If you're looking for convenience, then USB drives are a good option - cheap and versatile!

[sushrutha]

Hi ...
Can someone explain me as how to use this feature.
I have a pioneer DEHP 5990IB HU, And a bluetooth enabled Mobile which has a feature " Play song via bluetooth device " .

[hemanthisgreat]

Originally Posted by sushrutha

Hi ...
Can someone explain me as how to use this feature.
I have a pioneer DEHP 5990IB HU, And a bluetooth enabled Mobile which has a feature " Play song via bluetooth device " .

your HU does not support bluetooth, its that ur phone has bluetooth capability, you cannot use the feature discussed in this thread

[sushrutha]

Originally Posted by hemanthisgreat

your HU does not support bluetooth, its that ur phone has bluetooth capability, you cannot use the feature discussed in this thread

Well my HU does support bluetooth. I think i have to put a dongle to HU via the USB cable . Is it so?
My HU manual says - BLUETOOTH ADAPTER READY ( vIA EXT).