Bluetooth car audio issues

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d3Xt3r

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Topic # 129165 5-Sep-2013 17:03

Hi all,

I just upgraded my car's head unit and speakers from the factory setup and it sounds awesome!
However, I'm really disappointed by the quality of the bluetooth streaming from my Nexus 4 to the deck unit (Sony WX-GT90BT).
The sound is a bit distorted - with some crackling and doesn't have much clarity.
Now I'm not sure if it's the Bluetooth of the N4 or the Sony that's cause of the issue.

Assuming it the N4's Bluetooth that's not up to mark, suppose I pair my phone with an external high-quality Bluetooth car kit, and connect the said car it to my deck via aux, would it improve the quality? If so, any recommendations for the best quality Bluetooth car kit money can buy?

Edit: It looks like the N4's Bluetooth *is* the culprit! So, looking for recommendations for the best Bluetooth car kit! :)

Edit2: Wait, I wasn't thinking clearly. If the N4's bluetooth is bust then using a bluetooth car kit won't make any difference. :(

I might just have to go and buy another phone which has a good BT output..

Edit3: It looks like some Bluetooth headphones work just fine with no distortion - then perhaps, could it be an issue with the Bluetooth protocol / implementation used by car stereos? Perhaps the car kit idea may just work afterall?

Klipspringer

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Reply # 890472 5-Sep-2013 17:58

you sure ur phones media volume is not on Max? mine distorts when it is.

d3Xt3r

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Reply # 890638 5-Sep-2013 21:13

Klipspringer: you sure ur phones media volume is not on Max? mine distorts when it is.

Hmm, good point. I had to set my vol to max because the output was so low.. I'll lower it but increase the deck volume and see how it goes. Thanks!

Klipspringer

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Reply # 890655 5-Sep-2013 21:54

d3Xt3r:
Klipspringer: you sure ur phones media volume is not on Max? mine distorts when it is.

Hmm, good point. I had to set my vol to max because the output was so low.. I'll lower it but increase the deck volume and see how it goes. Thanks!

Set the phones media volume to about 95%

Check if your head unit has an SLA (source level adjustment) setting. My Pioneer has.
It will give you the ability to equalize the volume between the difference sources.

richms

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Reply # 890679 5-Sep-2013 23:29

Plenty of bluetooth modules cant handle the full output, On my craptastic warehouse stereo I have to run the phones at about 3/4 of the way up the bar to not get clipping.

However even when not clipping, its noticeably worse than the aux in connection for sound quality, even on low quality rdio playback its way worse on the bluetooth. Unfortunately the line in on that cheapie is one that goes thru the faceplate so is noisy as anything.

Richard rich.ms

d3Xt3r

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Reply # 890743 6-Sep-2013 09:19

Thanks guys, a combination of a lower volume and a fix on the XDA forums seems to have cleared up the crackling issues, but the quality is still poor - probably as bad as FM.

----

I've come across a couple of projects using a Raspberry Pi as a bluetooth receiver, might give that a go instead.
Just need to buy a Bluetooth 4.0 receiver and a USB DAC.
Might even attach an LCD to it to display Artist/Title info. :D

Klipspringer

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Reply # 890757 6-Sep-2013 10:03

How is the quality poor?

Is playing the same thing via an aux cable noticibly different to playing it via bluetooth?

For me the poor quality comes from the source. Ie, low bitrate mp3's, listening to online streaming etc ...No different if I play it via bluetooth or aux cable.

Try playing a good quality mp3 (256kbps bit rate or higher) over bluetooth and see if that improves things. Compare that with aux cable and that should narrow things down.