brechbt

It's obvious that the audio system in the TL must have a DAC, because it can play files from flash drives connected to the USB. Can anyone tell me if the TL's DAC is used in playing music from an iPod, or is the iPod doing the converion?

I'm asking because I'm looking at getting an iPod just for the car, but have been reading a lot of dissatisfaction with the sound quality in current gen iPod classics. The TL's DAC, on the other hand, seems to do a good job; I'm pretty impressed with the sound quality I'm getting when playing files from a flash drive.

If the TL is handling all conversions, then I'll get the current gen iPod classic--bigger drive, more robust feature set, etc. If the conversion is occurring in the iPod and an analog data stream is just getting passed to the TL's system, then I'll probably go with an older iPod classic that has a more highly regarded DAC chip.

I searched already here; couldn't find anything. Thanks to anyone who has some answers.

sluzynsk

The iPod DAC is doing the conversion. The stereo can't deal with .m4a files unless they are coming from the iPod - you can't play them from a disc or a USB stick.

I use an iPod nano, I just leave it in the center console plugged into the USB port and it works great. Sound quality isn't as good as a DVD-A but it works.

ll_22

I have a different experience, I had been using USB drive to play mp3's but I recently switched to an iPod and the mp3's actually sound noticeably cleaner!? I'm not sure if it was just me but if the music is converted in the iPod instead of in the TL audio unit then this makes sense. Also I leave certains types of music (classical, jazz, vocals) in .wav format to play off the iPod (4th gen nano).

I hate Apple but they have no real competition for the iPod thus far.

avmike

[QUOTE=sluzynsk;13063594]The iPod DAC is doing the conversion. The stereo can't deal with .m4a files unless they are coming from the iPod - you can't play them from a disc or a USB stick. [QUOTE]

Can't be, if the ipod is connected via USB. USB is a digital connection so the digital to analog conversion is happening in the Acura. Unless of course toy have the ipod hooked up "old school" to the analog input.

brechbt

[QUOTE=avmike;13064251][QUOTE=sluzynsk;13063594]The iPod DAC is doing the conversion. The stereo can't deal with .m4a files unless they are coming from the iPod - you can't play them from a disc or a USB stick. Sluzynsk: FYI, .m4a files are playing just fine for me from a thumb drive. I have the Tech package--not sure if that makes any difference.

avmike: Your answer makes perfect sense. However, I'm not really sure about it. iPod's are designed to interface with a variety of docking stations that have powered speakers. For these boom-box style devices to work, they are either converting a digital signal coming from the iPod, or they are simply amplifying an analog signal coming out of the iPod's docking port. It's not obvious which of these is the case--it would seem that letting the iPod do the conversion is simpler and let's the docking station be simpler and cheaper to produce. If the iPod is in fact outputting analog signals through the docking port, then the Acura engineers could have decided to use them--the USB connector is just a set of wires, and presumably could be engineered to transmit a variety of signal types.

I may have to see if Acura technical support can clear this up. Thanks for the responses.

avmike

While the Ipod connector may indeed carry analog, the USB port on the Acura is a standard USB port. Used for digital USB data only. Not possible to pass analog audio through it. Nor will the apple-supplied Ipod to USB cable pass analog.

ll_22

I think we may both be correct. I am mistaken in saying that music hookup via USB is using the iPod DAC because it cannot be an analog output. However, the music stored on the iPod is likely converted to another digital audio format that is then ported over the USB to the TL stereo system.

I don't know what the correct terminology is but the iPod is doing decompression and conversion of music files separate from the TL system. The TL system cannot convert .wav files from an USB for example, and therefore the iPod is doing this conversion then sending it out via the USB in a digital format whatever that is. This conversion processing appears to be superior (irregardless of file format) from the iPod is my conjecture.....

brechbt

Here's an update on this question. I contacted Acura customer relations about this. The person I spoke with was not a technical expert, and did not have a technical support person to transfer me to; he researched this himself and got back to me. His answer is that all analog conversions are taking place in the Acura's head unit. However, as ll_22 speculated, the iPod is outputting a digital signal to the Acura that has been converted in some fashion. This is to allow the iPod to handle DRM content. The nature of this interim digital file isn't clear, but I have my answer: the type of iPod you connect, and its DAC, is not relevant to the sound quality you're getting in your TL, since all analog conversions are taking place in the TL's electronics.