MDI Interface

[Lance B]

Hi all,

I have an MDI Interface installed in my R36 Passat and connected to the standard stereo system and would like to know the best media device to use which does not degrade CD quality sound.

I know I-Pods use some sort of compression and will therefore degrade the sound but is it noticeable? Alternatively, can a large 200Gb+ hard drive be used with uncompressed CD's? Is there such an option?

Any suggestions would be appreciated.

[Steve]

As far as I'm aware, the MDI interface is incapable of playing uncompressed formats.

Just use high quality MP3's. You may notice some sound quality degradation, but not much.

[nting]

Yes, compression does not always mean the audio quality will drop to a poor level. High quality MP3s using higher bitrates (these will generally be larger in file size as a result) and still sound excellent. True audiophiles may argue, but you should try it for yourself to see if you are happy with it. You should create your own high quality MP3s to ensure that they are of the best quality possible.

[Lance B]

Yes, compression does not always mean the audio quality will drop to a poor level. High quality MP3s using higher bitrates (these will generally be larger in file size as a result) and still sound excellent. True audiophiles may argue, but you should try it for yourself to see if you are happy with it. You should create your own high quality MP3s to ensure that they are of the best quality possible.

So, what you're saying is that if I get an IPod and record it with MP3 quality, that should sound good enough?

[bennobee]

Firstly what cable did you get with the MDI ? You get a range of cable options from ipod to USB so that makes a difference. As for the output well if you go with ipod you can sue the apple loss less format. It means your not compress the sound at all and its as good as the cd. It takes up a LOT more room though so you will not get so many songs on the ipod but problem solved. DId you get the dynaudio package as well ?

[Lance B]

[QUOTE=bennobee;332951]Firstly what cable did you get with the MDI? You get a range of cable options from ipod to USB so that makes a difference./QUOTE]

I had the i-Pod cable installed.

As for the output well if you go with ipod you can sue the apple loss less format. It means your not compress the sound at all and its as good as the cd. It takes up a LOT more room though so you will not get so many songs on the ipod but problem solved. DId you get the dynaudio package as well ?

Not the Dynaudio, just the standard system which sounds quite good for a standard system - supplosedly 250 watts and 8 speakers although I think that would be peak watts not rms, although it doesn't have a pinch on my home system which is a Plinius 9200 amp with 350watts RMS into my 4 ohm Orpheus speakers with a Marantz SACD SA7001 KI player. My home system is amazing.

I just picked up an i-Pod classic with 120Gb hard drive, so I am sure this will be more than enough to put my uncompressed favourites on.

[Lance B]

Well, thank you to all those that responded to my thread about the MDI interface feature.

Many here that already have and use this feature probably already know how good it is, but for those that have not experienced the iPod interface, it is fantastic.

Being able to access all my CD's through the 120Gb iPod is wonderful, especially as the full functionality of the iPod is completely accessible, ie the fact that I can call up music either by album, artist, song, genre, or whatever, from the screen of the car's stereo, is a great feature.

Previously, as we all know, we could only have 6 CD's already loaded in the CD player and, depending on mood, they weren't always the one's we may have wanted to listen to. Even though I had another 15 CD's in the glovebox or in the centre console, it was always limiting as to what I felt like listening to and it would be a great hassle to find the right one, then have to get it out of the case, then load it up, all of which took time and is not safe when driving along. Now I have all my CD's recorded on the iPod, I can access them all very easily and quickly and there's still plenty of room left on the iPod disc drive! I think I've only used about 20Gb so far, so there's about 100 to go!!

The sound quality pretty much on par with the standard CD player, so this is better than I thought it would be. Highly recommended.

[stevielloydoakridge]

I am currently waiting for an ipod MDI for my R36 (next week)
As for sound quality I think probably the amp and speakers are more important than whether the format is compressed or not. A car is not an ideal listening environment, my stock standard (ie not dynaudio) sound system in the car sounds fine and Im not really that concerned about the compressed format given it is high frequency compression and that is where there is a lot of car noise anyway

[Lance B]

I am currently waiting for an ipod MDI for my R36 (next week)
As for sound quality I think probably the amp and speakers are more important than whether the format is compressed or not. A car is not an ideal listening environment, my stock standard (ie not dynaudio) sound system in the car sounds fine and Im not really that concerned about the compressed format given it is high frequency compression and that is where there is a lot of car noise anyway

Amp power and speaker quality are definitely the more important components and as you say, they are quite good in the standard form in the R36.

Having had the iPod installed for a few days, I love the fact that I can listen to any of my albums that I want. With iTunes, you can even adjust the EQ and output level (within reason of course) on your recordings, so this goes some of the way to addressing some short comings that the iPod system may have.

[Swallowtail]

Amp power and speaker quality are definitely the more important components

This is a religious argument - if the quality is not there in the source then no amount of good amp and speakers can bring it back. All they will do is amplify and faithfully reproduce the crap source.

Source / amp / speakers needs to be a balanced proposal for a good result, but at the end of the day - garbage in garbage out, regardless of how much you spend on super dooper speakers or big amps.

This is a fairly balanced comment on the subject:

http://www.uhfmag.com/book3.html

[Lance B]

This is a religious argument - if the quality is not there in the source then no amount of good amp and speakers can bring it back. All they will do is amplify and faithfully reproduce the crap source.

Source / amp / speakers needs to be a balanced proposal for a good result, but at the end of the day - garbage in garbage out, regardless of how much you spend on super dooper speakers or big amps.

This is a fairly balanced comment on the subject:

http://www.uhfmag.com/book3.html

I do agree but in a car environment, the nuances and subtleties of good source componentry are often lost. Things like placement of instruments, decay of instruments etc are generally not heard.

With my home system, I can readily tell the difference between source components, but then I can even more tell the difference between speakers and a good high power amp. As stated by me in a post above, I have very serious top end gear for my home system, so I am no stranger to good source componentry, as I have a Plinius amp @ 200W RMS into 8 ohm and 350W RMS into my 4 ohm Orpheus Speakers with a Marantz SA7001 KI SACD player. It sounds remarkable to say the least.

I have also installed high quality, high power systems into a few of my previous cars and realistically, the major improvements are made in the power amp, speaker and cable areas, not so much the signal source as these are really quite similar.

Having said that, as you say, you do need to keep a reasonable balance with how much you spend on each component, it's just that what I am saying is that in a car environment, much of the nuances that we hear and are available in our home system are lost.

I will add to this that I have done quite a bit of experimenting and testing with a sound level meter in my home environment on my previous home stereo system. It is quite amazing how different frequencies can either be almost lost completely or doubled up due to room acoustics. Moving even half a meter one side or the other can result in either a frequency being lost or accentuated depending on where you stand. It is also amazing to find that by moving large pieces of furniture even as little as 100mm can make a dramatic improvement or a detrimental impact on bass, also to imagery, depth perception, instrument placement, ambience and very importantly harmonics - which are very important to how an instrument sounds.

[Swallowtail]

Fair comment... Sound stage in a car is pretty limited. My setup at home is Arcam / Linn, although to be honest these days my primary source is a PC Media Center, which really doesn't show it off to best advantage.

My comments I guess were more in response to the previous comments about not being concerned about the source being compressed and that good speakers are more important than teh quality of the source.

That I disagree with. A 128kbps MP3 sounds crap compared with a 300+, and a good system will show that very obviously. The best speakers in the world won't rescue the mush of a 128kbps MP3.

Nor will a fantastic amp and speakers rescue the sound from a $99 K-Mart special head unit.

With cars with a good quality built-in head unit like VWs tend to have these days, I wouldn't bother replacing it - so in that case yes I agree that amp and speakers would be upgrade choice. But as to what the source that I push into the head unit in the case of MP3s etc, different story.

[Lance B]

Fair comment... Sound stage in a car is pretty limited. My setup at home is Arcam / Linn, although to be honest these days my primary source is a PC Media Center, which really doesn't show it off to best advantage.

My comments I guess were more in response to the previous comments about not being concerned about the source being compressed and that good speakers are more important than teh quality of the source.

That I disagree with. A 128kbps MP3 sounds crap compared with a 300+, and a good system will show that very obviously. The best speakers in the world won't rescue the mush of a 128kbps MP3.

Nor will a fantastic amp and speakers rescue the sound from a $99 K-Mart special head unit.

With cars with a good quality built-in head unit like VWs tend to have these days, I wouldn't bother replacing it - so in that case yes I agree that amp and speakers would be upgrade choice. But as to what the source that I push into the head unit in the case of MP3s etc, different story.

Can't argue there.

My iPod music is being recorded on MP4a and 256kbps, so it isn't too bad, but as you say, there is a very slight drop in sound quality, mainly at the high end, but I think most would not even hear it with the standard sound system. This is exactly what you are saying, and I do agree with overall, in that if we were to upgrade the amps and speakers we would quickly here the limitations of the source, but we would need to upgrade the amp and speakers in order to hear it, so it is basically an upgrade *all*, not just part.

[stevielloydoakridge]

Point taken about garbage in garbage out
I still feel the rate limiting step for car audio is the imperfect environment that the sound system has to perform in (interior of a car which is a little short of audiophile quality). The argument about compressed data may be different in a dedicated sound room/no ambient noise but in a car I personally believe that the small drop in quality of the compressed high frequencies is a much less significant factor than the listening environment of a car

[Swallowtail]

Point taken about garbage in garbage out
I still feel the rate limiting step for car audio is the imperfect environment that the sound system has to perform in (interior of a car which is a little short of audiophile quality). The argument about compressed data may be different in a dedicated sound room/no ambient noise but in a car I personally believe that the small drop in quality of the compressed high frequencies is a much less significant factor than the listening environment of a car

Do an experiment - rip a CD at 128kbps and play it in your car and then do it at 320kbps. Or against the original CD - although then you are bringing in another variable - your car CD player against its MP3 system.

Tell me then that there is no difference. Subject to obviously a half-decent car hifi system. 128 I feel is sub-par. I try to maintain at least 256, ideally 320. I have had some really bad ones at 128. You think they sound good until you listen to a better one. Storage is so cheap these days I see no reason to compromise to poor quality compression rates.