AudioBear

To say I am not over-whelmed with the Bose system in my 2014 A6 TDI would be an understatement but knowing that source material can have a big impact on audio output quality, I have searched the forums for advice on what is the best medium for audio quality playback. It appears that most digital inputs to the MMI system are limited to 320 kbps and 48kHz sampling. See snagitseven's post at:

https://www.audiworld.com/forums/sho....php?t=2840907

This is certainly not as bad as a highly compressed MP3 on an iPod but it is not full CD resolution either. Obviously playing a music CD would allow full CD audio but would be limited to 16 bit word length at 44.1kHz sampling. After playing around with various input sources using the same source CD (Chesky's Rebecca Pidgeon, The Raven), I subjectively came to the conclusion that the CD player sounded best of all the inputs I tried. I know nobody wants to play CDs anymore, they are just so 20th century, but this got me to thinking.

Knowing that the DVD standard allows for 192Khz/24 bit resolution PCM audio, and that the DVD player would play audio but not video while the car was in motion (yes I know that can be changed), I wondered if a Music-DVD containing hi-res audio files would sound better than a CD. I made a Music-DVD using Toast 10 (Mac OSX) that contained the Chesky recordings of SaraK's What Matters and Rebeca Pidgeon's Four Marys both recorded as 192kHz/24 bit AIFF files. These uncompressed full resolution files are big so I was only able to get two albums on a DVD. The resulting sound was in my subjective opinion stunningly improved. I won't bore you with all the audiophile verbiage because I am not an audiophile.

I would note that the industry asserts that good audio can't be heard in a car because of all the noise and the small and difficult acoustic environment. Balderdash! My Acura sounds a ton better than the Bose junk in our Audis and it plays a DVD-Audio disk that sounds quite good, and the Lexus standard audio system absolutely buries the Audi Bose. There is just no excuse for a high end car to have such a mediocre sound system. But, the high-Rez sound I heard with the Music DVD was strikingly better than anything I had heard out of the system before. Unfortunately it also betrayed the faults of the system like the thumping one note bass that is rendered from any music that has any kind of bass in it.

Having heard the improvement offered by 192/24 files, I made a similar disk with files encoded at 96/24. I could not detect a difference in sound from the 192/24 encoded disk. I did not pursue this further but it is possible that 48/24 would sound as good. It's possible that the 24bit encoding is making the biggest difference; and it's also possible that the audio decoding in the DVD section is just better. More possibilities could be explored here.

In the near future I plan to make a disk using ALAC (lossless encoding) files to compress the file size further. If this works it should be possible to put the equivalent of 8-10 albums of music on a single DVD which is a reasonable size for a playlist. If ALAC at 48/24 sounds good enough, some fairly long playlists could be saved onto a DVD. I hate going back to physical media and all its disadvantages but I am going to make a few DVDs and use them on long trips. I don't mind the Bose for trips around town but for a long days on the highway, I'd prefer the sound that I heard coming from the hi-res encoded DVDs.

I'd be interested in know if anyone else has a better solution. Specifically has anyone managed to get hi-res audio sources into the system any other way? I couldn't do it using the USB and Chip inputs. The screen appeared to read the files and often got the title right but said the track couldn't be played in one way or another--usually track error. One thing I also want to try is a small portable Hi-Rez audio player (eg. FiiO X5) plugged into the analog stereo audio-in jack using 3.5 mm pin or RCA jack output from the player. It could be that good analog signal in will produce a favorable audio output. Has anyone tried this? How good is the analog audio in? If it is good a small player would be preferable to DVDs for sure.

All things considered, I now realize that i should have sprung for the B&O audio upgrade. I will probably be going for an aftermarket audio upgrade. In the meanwhile, DVD encoded music will have to suffice.

Sorry for the long post but I thought there might be someone else out there who either wanted to know how to get better audio out of the system or who had a better way to do that.

DeerHunter

There's a timely article here about the relative importance of ultra-high-bit-rate recordings. It's a short read, but the conclusion is that it's vastly more important to start with the best quality and engineered sources possible. After that, the author states that there's little audible difference between CD quality (44.1/16) and anything theoretically superior. You might want to try downsampling your albums and seeing if there's a difference. You might be able to store 9-10 albums on a DVD instead.

I hear a lot of complaints about the Bose system but I honestly don't think it's that bad. I play all my music, using high-VBR MP3s, off SD cards and am reasonably happy. A touch more low-end would be nice, but the imaging and mid-range is fine. I don't have tin ears either, and have seen fit to splurge on a home theatre system that is head-and-shoulders above most things I've heard (and would otherwise have been sufficient to purchase a mid-range car).

subterFUSE

I did a full system upgrade to my Bose, and I'm very pleased.

As for audio sources, I don't think that the DVD player will play Apple Lossless files. Apple Lossless is not supported by the SD drive or Jukebox on the MMI, so I don't see any reason to think the DVD player would work. But I can't say for certain because I've never tried it.

You are correct that the best quality source for the MMI system will be CD/DVD physical disc.

As for me, my music collection is kept in Apple Lossless on iPods and my iPhone. I use 24/48k whenever possible, as this is the maximum resolution currently supported by iDevices. But the majority of my music is simply 16.44.1k because I ripped it from CD and there's no point in ripping at a higher resolution than the original.

I use the AMI input most of the time, but I did have an external D/A converter installed for my iPods. It's called an iStreamer 12V. If I use that, then it bypassed the MMI system completely and runs directly into my aftermarket processor (Audison BitOne).

My Audison BitOne processor has digital inputs and supports 24/192k audio, so in theory I could get a playback device with an optical output and go directly digital into my stereo.

NightCrawler

I'm no fan of the Bose myself and if I had to do it over I would pay for the B & O. As it is I listen to Audible 90% of my time in the car so it's tolerable. I came over from Acura and that system was much better. It too had the ability to play DVD Audio.

TheNit

Just a quick note that I went to the dealer and complained about "too little bass" with the Bose system and the tech found a TSB that he applied for the amp (code 30 to 40?) and I can actually hear the subwoofer now. Much better sound. I have MMI version 649 in a 2013 A6.

AudioBear

I can hear the difference between 44.1/16 and 48/24 using the same source material but I really agree with you that the biggest difference is to be found in the quality of the source material. The second most important difference is the playback system and maybe after that comes audio formatting that I am trying to optimize.

My Bose system has bass, it's just one note: thump thump thump. That's probably because Bose is asking a lot out of a pair of small woofers with no enclosures. They can't violate the laws of physics. When it comes to audio one man's reasonably happy may not be another's. It's all very subjective...but if you hear a big difference between the Audi Bose system and other makes like Acura and Lexus then it means that for you, it makes a difference.

subterFUSE

Yes, original recording quality and mastering are most important factor.

The Bose front midbass speakers actually do have ported enclosures, but the woofers are very small. Like. 4 or 5 inch.

DeerHunter

Go and ask for the update mentioned by TheNit. It must have been done to my system at one point or another, because the character of the bass changed considerably. To wit: It's no longer one-note. Sure, it could go deeper, but it's much better than before.

The Audi Bose system, btw, uses a single 12" woofer in the rear deck, running free-air. Apparently, it's a wimpy little thing that only weighs about 5 lbs. A lot of the mid-bass comes from the door woofers (8", IIRC) that are in tuned enclosures. In any case, I already have my aftermarket free-air sub and am just working up the nerve to tear the back of my car apart.

NightCrawler

I think that's my issue. I only plan on keeping the car for another 18-24 months. I just can't see ripping the vehicle apart to do upgrades that won't raise the value of the vehicle in any way. It isn't terrible, it just isn't as good as I would expect for a car at this price point. If the B&O had been half the cost it was I would have gotten it. Next time I'll just suck it up and get it.

salvadorik

Former A6 C7 with prestige package here. Not sure about Acura but Mark Levinson in Lexus (I have '14 Lexus IS350 F-Sport) is not impressive to say at least. Bose in A6 was/is marginally better than ML in Lexus. Bose sounds better at any volume level. Bose more clear and less distortions than ML. I had both cars at the same time and I compared side by side. Maybe ML in LS is awesome but not in IS/GS that is for sure.