Got 2013 G37 coupe with nav.
We all know that Bluetooth audio streaming has lower quality.
My question: is there a difference ,in your opinion, between a USB flash drive hooked into the car VS. your smartphone hooked with a USB cable?
Thanks

 

You cant hook up a smart phone via USB other than an Iphone.

Bluetooth sounds good to me. USB is equally as good.

An audiophile would have a processor with the device hard wired to the processor and by pass all of the factory stuff.

I have a bit ten D with a Galaxy note 2 wired in via 3.5mm to RCA cable. Im using flac ,wav, and 320kbps files.

 

Bluetooth streaming itself is no lower quality than any other delivery medium; its the bandwidth restrictions of the transfer mechanism that determine the overall audio loss. The iPhone will stream via Bluetooth with sufficient bandwidth to play uncompressed wav files so the Bluetooth is not the problem. Where things get dicey is when the signal degrades and the receive buffer on the car stereo empties. That causes audio drop out, dithering and compression; none of which is good for the audio quality. Providing your source material is high quality, you should not hear any difference whether you are streaming, using a flash drive or your iPhone through the data cable. A more important question for quality fiends would be what compression/storage method are you using to store your media?

 

Playing a mp3 on my cell phone (192 kb bitrate) via BT sounds worse than playing the same mp3 from a usb flash drive.

Phone is an evo 4g lte which supports BT 4.0, is plenty fast (8960 cpu). While the phone may support all the new fancy profiles, I believe the BT receiver in the car is significantly outdated.

 

there should be no difference between connecting an iphone via USB to having a flashdrive plugged directly to the USB, i have experienced lower sound quality over bluetooth as well playing the same exact file.