Has anyone else noticed that the CF card offers the best sound quality of all the music devices in the car. I havnt really played directly from the indash CD player, but im guessing that might actually be the best. After using the CF and music box for a while, then switching to the 6 CD changer in the trunk, that trunk unit sounds low and the quality is terrible in comparison. My guess is that because the trunk changer is hooked up through some sort of aux cable which allows more distortion threw the lines. The music box sounds great as well, but the cf card is hands down the best IMO. Some songs on half volume are louder then songs in the changer at full. Another reason for this im guessing is because im running all burned cd's in teh changer, and through the cf card there is no file conversion as its strictly drag, drop and listen.

 

the quality of mp3s vary greatly based on the encoding algorithm. If your mp3s on CF card are encoded at higher than 132kbps max that the music box encodes at, that would explain something.

I've used a couple of complex jazz CDs in the trunk changer and it sounded no different than the head unit player.

 

^YUP^ Digital is digital. Sound quality in digital media only depends on the encoding/decoding process. I'd understand if the comparison was between cassette and CD (analog vs digital) where there truly is sound quality loss but the digital format is all read by the same decoder chip in the sound system. 010101010 is the same on CF as it is on CD and hard drive.

 

beyond just bitrate the other options make a difference. joint-stereo, etc etc. the encoder algorithm makes a big difference too. LAME is one of the best mp3 encoders out, and depending on the track, lots of people can hear huge differences between lame encoded and fraunhofer encoded mp3s. of course the decoder, and headphones/speakers can make a big difference too.

 

theoretically its true that digital is digital. in a perfect world, that would be the case. i think its also important to consider, in addition to encoding and decoding, that most systems have some type of error correction that fills in missing data. a purely digital line coming from the trunk area could have some noise introduced. also, the gain at both ends may be different and the changer in the trunk could have a different processing algorithm.

all purely speculation here, but i'm sure it's not unlikely that the different source options are not perfectly matched and the listener could detect the difference.

 

The assumption here is that the trunk changer and the in dash changer are digital up to the DAC. It's entirely possible the trunk changer uses a built-in DAC and sends analog (haven't actually looked at the wiring or the specs). I'd be a little surprised considering it'd require two DACs and the expense would be silly to do such a thing.

Error correction on the reading device can make a difference, but that assumes that we're dealing with discs that have read errors. If we're talking interference on the run, we're talking some serious electrical interference (and I mean the kind that would have serious affects on your radio) to corrupt a non-optical, electrical digital signal assuming the cable is even remotely shielded. Gain should have nothing to do with it. Digital is digital, a bit is a bit no matter what. Now, gain may affect the integrity of the signal, but once again, with such a short run, we really are talking major EMI.