04-25-2011, 10:48 AM

Music Playback in BMWQuality Format Choices
I received my 2011 550i in March 2011. I have been experimenting with the vehicle’s sound system using different music playback formats when connected to either the USB ports or the console AUX input port. I enjoy listening to music, so I wish to play back selected music in my car with the best reproduction quality and highest fidelity.
After extensive informal trials and testing, I have discovered the following results:
1. For me, the best choice is music files stored onto a USB flash drive. The flash drive is connected to the center console USB port. The music is stored as *.WAV PCM 16-bit, 48kHz sampling rate formatting.
The remaining choices were tested and resulted in increased degradation of music audio quality.
2. Playback of music CD's using the vehicle's CD player. CD's are 16-bit 44.1kHz WAV files, so only slightly worse than #1 above.
3. Files which I stored on the USB flash drive in AAC MPEG 4 format. Although audio between the two methods of AAC is similar, the MPEG 4 container is better since the MPEG 4 container displays the artist and album names. AAC MPEG4 has metadata embedded with each music track and is used by the car to display these artist and album names. The car displays 'Various Artists' for WAV and AAC ADTS.
4. AAC ADTS format. The music has comparatively similar sound to MPEG4, but as stated in #3 above, no artist and album name is displayed.
Both AAC MPEG4 and AAC ADTS have the capability of increasing the amount of playable music to store for a fixed flash drive capacity since these music files are compressed. However, simply stated, the sound quality is not as good when compared to the uncompressed WAV files.
5. Playback of music files from the iPod, iPhone or MP3 player. These devices were connected using the headphone jack (mini-plug) to the center console aux player. The playback quality of iTunes music downloads or music MP3s is significantly lower. I discovered that connecting the iPod headphone jack to the aux input is better than connecting the iPod to the USB Port for two reasons: 1. The video continues to display on the device. Using the iPod connector to the USB center console USB port will cause the video to go black. 2. At the same time the headphone jack is used to playback any audio, the iPod connector can be connected to the center console power plug to charge the phone when a charger adaptor is used.
My auto's build date does not support BMW Apps, so using the iPod connector to the USB port may access features in Apps of which I am not aware,
6. Copying music files from CD or flash drive to the BMW's internal hard drive. I do not recommend this approach. BMW's compression format used when storing files onto their internal hard drive has very poor audio reproduction quality through their own high quality sound system when music is played from the hard drive. Is this store to then playback from the hard drive problem unique to my car or do others of you have similar experiences? If so, isn’t it strange that the high quality sound system was not fully exploited when BMW decided to allow storage and playback of music files on the hard drive?
7. The Bluetooth music feature was not tested.
Note: Placing any device in the auto's glove box USB port allows the USB external device to copy files to the auto's hard drive only. Therefore do not expect to use this port for music playback.
Recommendations. As a fellow BMW owner, we should convince BMW to support and build into their vehicle sound system the encoding and decoding of high quality audio compression format files. This post suggests the use of WAV music files, an uncompressed format, because of the poor quality exhibited by AAC, MP3 and the BMW's hard drive compression. But since WAV files are large, BMW should also consider supporting two technologically current lossless compression music formats, FLAC and ALAC (Apple Lossless). These two formats would allow owners to have a choice of playing selected high quality, high fidelity music (particularly useful when taking a long road trip).
Also, BMW should support better-than-CD quality music files, such as 24-bit, 88.2 kHz or 24-bit, 192 kHz.
Under the current recommendation, using a 16 Gigabyte USB flash drive, an owner can store up to 20 albums (approximately 150 songs) of 16-bit, 48 kHz WAV music. It is akin to taking 20 CDs in the car. The driver periodically replaces the files on the flash drive, or uses a second flash drive to increase his selection while on the road. Using a home or office computer with conversion software, stored music and/or CDs, the owner can develop his own playlist and store onto the flash drive(s) prior to departing on his trip.
For my tests I used the following:
1. Linn Studio Master recordings of Beethoven Piano Concertos http://www.linnrecords.com/recording-ludwig-van-beethoven--piano-concertos-3-4-5.aspx, and singer Barb Jungr http://www.linnrecords.com/artist-barb-jungr.aspx originally stored on a RipNas server in 24-bit, 192 kHz and 96 kHz compressed in FLAC.
2. WAV-MP3 conversion software http://www.wav-mp3.com/ . After several experiments at different conversion formats, bit sizes and sampling rates, I discovered that the best the BMW would playback is 16-bit, 48 kHz WAV PCM.
3. LEXAR 16 Gigabyte USB flash drive.
4. My new 2011 BMW 550i sound system.
**Support analogue! Still the best audio reproduction quality. Vinyl LPs are making a comeback.